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L71 Incubating and Hatching Eggs

1. During the work on egg incubation while waiting for the chicks to hatch stud ying the structure of an egg can be a valuable activity This can best be done by hard boiling eggs and then chopping them in half along their long axis still inside the shell if possible Comparisons can then be made with a raw egg This is best studied by placing the egg in a dish lined with tissues and making a window in one side by carefully chipping away the shell and membranes with forceps or tweezers gure 11_ Opening up a raw egg Important features of the design of an egg are shown in Figure 12 and disc ussed overleaf 40 igure 12 The contents of an egg INNER MEMBRANE SHELL OUTER MEMBRANE AIR SPACE THE PARTS OF AN EGG AND THEIR FUNCTIONS OPENING UP FERTILE EGGS BEWARE OF PUPILS REACTIONS WHITE STRAND OF WHITE SUPPORTING YOLK ICHALAZA i The shell which is porous it must be to allow oxygen in and carbon dioxide out If possible look at a piece of shell under a microscope to see the holes ii The membranes which help to prevent too much water being lost through the pores in the shell a necessary evil to allow gas exchange Blood vessels from the developing embryo later form a network beneath the membranes which then act as a surface to help exchange of gases in and out Tuming the egg during incubation helps to prevent the embryo in its early development from sticking to the membran
2. A tiny still air incubator consisting of a clear plastic cylinder with octagonal end units An egg tray fits inside the cylinder with removable plastic dividers to adjust the size of the egg channels The eggs are gently warmed by heat emitted from 16 black element strips printed onto the plastic cylinder Eggs are tumed manually by just rotating the entire unit rather than opening it up and moving eggs individually The mercury thermometer fits into a socket in one end unit and is read through the plastic cylinder Humidity is provided by adding water to troughs at one end of the egg tray Ventilation holes pierce one end unit natural convective ventilation Manufactured to BS 3456 and EN 60 335 An easily accessible control plus electronic thermostat and indicator lamp display are fitted in one end panel Fine adjustments are made with a small screwdriver 10 hens eggs Yes if a special cradle is used The incubator is suspended in the cradle which then rocks the eggs from side to side through a 45 angle in each direction A motor in one end of the cradle slowly turns an arm which moves the incubator continuously through two tums per hour Viewed directly through the plastic cylinder However the heating strips obscure the view to some extent and as chicks hatch a build up of moisture causing condens ation may further reduce visibility 1 0 kg incubator 1 0 kg cradle 34 x 15 x 15 cm high With cradle 41 x 17 x 23 mm h
3. As well as manufacturing incubators Brinsea also supplies various books that will be of interest to schools intending to keep the adult chickens they have hatched or incubate the eggs of other species such as ducks geese or quail Contact Brinsea for a current list of titles Other suppliers also have books Contact individual suppliers for their latest lists Baby Animals series Chick 1844580873 Hdbk 10 99 For children 4 6 years information book with big bright photographs How Things Grow From Egg to Duck 1841383716 Hdbk 10 99 1844582566 Pbk 5 99 For children 4 7 years photographs and clear simple text Life Cycles series Ducks and Other Birds 1841388645 Pbk 5 99 For children 7 10 years an in depth look at life cycles This maintains and supplies rare domestic breeds as well as fertile eggs It prod uces a range of books in the Golden Cockerel series which ranges from guides for beginners to specialist books on rare breeds Details are on the DFT web site Watch Me Grow series Duckling 1405301600 499 For children 4 years an animal s eye view on the growth of a chick From Life Cycles Big Book series Lifestyle of a Chicken Big Book no SBN but code SBIGCHICK 18 50 This has large photographs showing every stage of the life cycle Life cycles series From Egg to Chicken 0749631449 5 99 For children aged 4 11 years a simple introduction ti life processes Watch
4. FROM THE DOMESTIC FOWL The trust produces a wide range of posters that feature many varieties of TRUST poultry waterfowl and other domestic fowl Call for details or see the web site FROM PHILIP HARRIS Life Cycle Sequences A23607 19 37 EDUCATION As from LDA FROM LDA Life Sequences Cards LL00642 1899 LIVING amp LEARNING 40 AS size full colour photographs illustrating the life stories of five organisms one set of these shows the chicken Time and Growth LL06014 9 99 Designed to help children understand the concept of time the pack contains 60 cards with colour illustrations rather than photographs showing changes over time One sequence depicts the changes from an egg to a bird FROM PICTORIAL CHARTS 4 Chicken Story PT T801 5 99 EDUCATIONAL TRUST PCET A laminated frieze 21 x 152 cm using photographs to show the development of a chicken FROM TTS Life Sequences Cards LSEQ 18 80 As from LDA Chick Life Story as from PCET SCHICK 5 75 The chick s life story shown in 8 photos in poster format 152 cm x 21 cm 4 MODELS FROM GLS Life Cycle Model sets 332377 69 99 Made from tough inert foam Designed to be handled by young pupils as part of their studies Includes the life cycle of the frog butterfly and flowering plant as well as a chicken Greatly simplified models show the key features and structures There is a guide and background notes 48 5 SLIDE SETS FROM BANTA LTD FRO
5. an egg must lose a certain amount of water during inc ubation if the chick is to emerge satisfactorily See section 5 2 for more formation WET BULB THERMOMETERS Some incubators are supplied with a wet and dry bulb thermometer The wet FOR HUMIDITY bulb is for obtaining readings of humidity However it is very difficult to ob VERY INACCURATE tain accurate readings with such a device and we would not recommend that they are used If used no reliance should be placed on readings obtained It is better to check humidity by assessing the effects on the egg as described later rather than to obtain actual measurements ELECTRONIC INSTUMENTS Relatively accurate electronic instruments for measuring humidity called hygrometers are now available but the most useful of these are quite expen sive A pocket sized combined temperature and humidity measurer code AHT 305 is available from ATP Instrumentation at 29 95 exc VAT which could be placed inside an incubator but this could be too large for the smallest models If schools would like details of such equipment they should contact the CLEAPSS Helpline Manufacturers also supply units which will control the humidity in certain of their incubators These are however more costly than the incubators themselves and so we have chosen not to consider them here These may be available locally as freezer alarm plugs or special units can be purchased from egg incubator suppliers Brins
6. so it is necessary to remove the lampshade or cover and insert at least a 100 W bulb Check that this produces a sufficiently high temperature in the brooder and if necessary use more than one lamp A thermometer to check the temperature in the brooder will be required a simple room thermometer can be used for this In the early days after hatching the chicks must be kept very warm at about 35 C 95 F As they increase in size the temperature can be reduced by about 3 C 5 F each week Chicks will need to be given some warmth in a brooder for about 6 weeks until they have acquired their adult plumage Experiment with the height of the lamp above the brooder to obtain the correct temperature before adding the chicks The lamp should not normally be lower ed so that it is within the walls of the brooder as overheating may occur When the chicks are installed watch their behaviour and adjust the height of the lamp if necessary It is normal for the chicks to avoid the central spot immediately below the lamp but if they move to the periphery of the enclosure and possibly also show some distress with open beaks and panting it is evidently too hot Huddling together tightly is a sign that chicks are too cold 6 3 Feeding and watering the chicks Chicks that have just emerged from the shell do not require food for the first 24 hours what is left of the egg yolk will provide nutrients during this period Once the birds are ready to
7. until their plumage has dried and they are able to stand They are then best picked up by cupping gently in both hands The legs should project through the fingers or the bottom of the cupped hands The aim is to restrain the animal and not squeeze it tightly The neck is particularly fragile so care should be taken when handling As the birds grow older essentially the same technique is used approaching the animal from behind and holding the wings down against the sides of the body while lifting with both hands To avoid undue stress to the chicks handling by children must be carefully supervised and Kept to a minimum See also comments on hygiene in section 9 While the chickens are immature sexing is definitely a job for the expert unless eggs are hatched of a particular variety which has slightly different markings on the plumage in males and females eg Warren variety For most people sexing at this stage is not really feasible As the birds mature however and begin to develop their adult features sexing becomes somewhat easier for example when the birds are 8 10 weeks old The males are generally larger animals with bigger and brighter combs on top of the head and larger folds of fleshy skin below the beak Both hens and cocks have a spur on the back of each leg but this tends to be larger in males 36 MAKING PLANS IN ADVANCE CONTACT RURAL amp CITY FARMS ONLY HENS OR ADULTS MAY BE ACCEPTED
8. with warm water during incubation foll owed by a drying out period just before birds start to emerge This can be dangerous if overdone and insufficient moisture is lost as a result It is better to raise moisture levels in the incubator a little and assess whether the correct humidity has been achieved by candling see page 25 and then make any nec essary adjustments Turkey duck and goose eggs may benefit from being sprayed with warm water after the shell has been broken pipping and the young bird is struggling free Pheasant eggs must have a very high humidity after pipping In all cases turning of eggs should be stopped around 3 4 days before hatch ng is expected 27 Table 3 Incubation data for various birds other than chickens Bird Incubation time days Temperature Egg size conversion factor Bantams 19 24 38 39C 100 5 102 F 120 Ducks 28 35 38 39C 1005 102 F 0 75 Geese 28 32 38 39C 1005 102 F 0 40 Guinea Fowl 28 38 39 5 C 100 5 103 F 170 Pea Fowl 28 38 39C 100 5 102 F 0 60 Pheasants 24 38 39 5 C 100 5 103 F 1 50 Quail 16 23 38 39 5 C 100 5 103 F 2 50 Turkeys 28 38 39C 1005 107 0 60 28 STOP TURNING EGGS ON DAY 18 INCREASE HUMIDITY FOR HATCHING ALLOW HATCHING TO OCCUR AT ITS NATURAL RATE DO NOT INTERFERE UNNECESSARILY HATCHING TIME IN OTHER SPECIES ALLOW NEWLY HATCHED CHICKS TO REST THEN MOVE
9. ACCOMMODATION INCLUDING A COVERED RUN WILL BE REQUIRED FEEDING THE ADULTS LIMITED KITCHEN SCRAPS A SOURCE OF GRIT CALCIUM and VIT D CHOOSE DUCKS OR OTHER SPECIES ONLY AFTER GAINING EXPERIENCE WITH REARING CHICKENS their consent may be prudent The full and whole hearted approval and co operation of the school premises manager is also quite essential It is not within the scope of this guide to give full details of rearing adults and there are several publications which can provide extensive discussion see section 11 Neverthe less a brief outline of what is involved is given below The adults will need housing that provides a secure dry shelter in which they can roost and escape inclement weather Consideration should be given to the probability that mice and rats will be attracted unless precautions are taken a shelter raised off the ground will make it more difficult for vermin to become established The shelter should have at least one raised perch and to facilitate cleaning out waste it is customary to fit a board below the perch onto which the birds droppings will fall The floor of the housing should be covered with wood shavings peat moss substitute and or straw Feeders drinkers and nest boxes will also be required If one of the aims of keeping adult chickens is to collect the eggs that are laid throughout the year it will be necessary to provide artificial lighting in the shelter to extend the natural day l
10. Humidity levels should ideally be varied during incubation but it is difficult to give precise advice As a general rule during the first half of the incubation period the humidity should be at a low to medium level the second half requires a medium level of humidity Some authorities recommend a dryer atmosphere around day 18 to help the chick break into the air space As soon as the eggs become pipped with the chick starting to break out of the shell the humidity should be raised to a high level for hatching It is essential that the eggs lose about 12 15 of their mass over the incuba tion period Humidity that is too high or too low will cause too little or too much mass to be lost Water loss can be monitored by measuring loss in mass by weighing the eggs or by observing the size of the air space using a tech nique called candling see section 5 3 Measuring the loss of mass is prob ably the better technique to use but is more troublesome to carry out and requires a reasonably accurate balance Candling requires some skill By removing a batch of eggs and weighing them at regular intervals the loss in mass can be monitored and adjustments to humidity made as appropriate It is better to measure the mass of several eggs and calculate an average loss per egg because the balance available is probably unlikely to be sufficiently accur ate for small masses Ensure that the eggs are not excessively chilled when they are
11. Pearson Customer Operations Edinburgh Gate Harlow CM20 2JE Tel 0870 607 7600 Fax 0870 850 1115 E mail customerservice dk com Web site www dorlingkindersley uk co uk FACE FARMING AND Arthur Rank Centre Stoneleigh Park CV8 2LZ COUNTRYSIDE Tel 02476 853089 and 02476 858261 EDUCATION E mail enquiries face online org uk Web site www face online org uk GAMEKEEPA FEEDS LTD Southerly Park Binton Stratford upon Avon CV37 9TU Tel 01789 772429 Fax 01789 774875 E mail info gamekeepafeeds co uk Web site www gamekeepafeeds co uk GLS EDUCATIONAL SUPPLIES GRIFFIN EDUCATION JOHN E HAITH PHILIP HARRIS HATCH IT INCUBATORS ROB HARVEY INSECT LORE INTERHATCH KORTLANG amp KORTLANG LDA LIVING EGGS IVAN MEARS NATIONAL FEDERATION OF CITY FARMS AND COMMUNITY GARDENS OXFORD EDUCATIONAL RESOURCES P AND T POULTRY PICTORIAL CHARTS EDUCATIONAL TRUST PCET SOLWAY FEEDERS LTD 1 Mollison Avenue Enfield EN3 7XQ Tel 020 8805 8333 Fax 0800 917 2246 E mail sales glsed co uk Web site www glsed co uk Bishop Meadow Road Loughborough LE11 ORG Tel 01509 233344 Fax 01509 231893 E mail griffin fisher co uk Web site www griffineducation co uk 65 Park Street Cleethorpes DN35 7NF Tel 0800 298 7054 Fax 01472 242883 E mail seeds haith com Web site www haiths com Findel House Excelsior Road Ashby Park Ashby de la Zouch LE65 ING Tel 0845 120 4520 Fax 01530 419492 E mail customerservi
12. THEM TO A BROODER HATCHING EGGS and REARING THE CHICKS TO ADULTS Towards the end of the incubation period after day 18 the eggs no longer need to be turned as the chicks have largely completed their external development and the animal is manoeuvring itself into the correct position to make the initial break in the egg shell the process called pipping Ensure that ventilation is adequate as there is a real risk that the chicks can be suffocated by a build up of carbon dioxide at this critical time Ideally the air in the incubator should be drier on day 18 to help the chicks break through the egg membranes into the air space As soon as eggs are piped however a high humidity is needed to stop exposed membranes from drying out becoming tough and leathery and preventing normal hatching In many situations however all eggs will not pip at the same time and so it will be mpossible to provide the best conditions for both pipping and hatching Thi when a second incubator used as a hatcher is ideal eggs are transferred in batches as they become pipped Without a separate hatcher wait until about a third of the eggs have pipped and then increase humidity At this stage do not keep opening the incubator to check on progress as this will allow the moist air to escape which takes some time to build up again 6 1 The chicks hatch On day 21 though there is often some variation in development rate the chicks should begin
13. The water container is fiddly to refill The all plastic construction is easy to clean Advice about this and other aspects of operating the incubator are contained in the detailed instruction book P and T Poultry imports red and yellow versions the red is cheaper 99 95 cf 108 99 but is not fully insulated A fully automatic version will be available from P and T Poultry in 2006 costing 138 99 and possibly also from other suppliers A converter plug is required All the suppliers will accept orders on official school order forms Please sce note about delivery costs in section 4 2 7 Curfew 136 and 137 These incubators or earlier versions were very popular and purchased by many educational establishments in the last 30 years They may still be in use and or made available for loan CLEAPSS made many attempts using all possible means to contact the last known owner of the company and did obtain one response indicating in July 2005 that the company would be trading again in about 6 months Further attempts to clarify the position have failed and so we can make no comment on the possibility or reliability of supply We have been informed by one supplier of Curfew incubators in this country Interhatch that it has spares for these models and will repair them too Model 136 Model 137 Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Ma
14. be moved to the brooder an initial feed of finely chopped hard boiled eggs is ideal After the first day in the brooder the chicks should be given high protein chick starter crumbs This diet could be main tained for the next 6 8 weeks but many introduce some chick corn into the diet after a couple of weeks Some authorities suggest that for the first week chick crumbs should be moistened with water or milk 32 PURCHASING FOOD FOR CHICKS EXPECT A LOT OF FOOD TO BE WASTED DO NOT USE OPEN DISHES CONSTRUCTING A D I Y FOOD HOPPER A local pet shop may be able to supply such foods but not necessarily very economically However supplies are available from John E Haith in 6 kg 15 kg and 25 kg packs Order High protein crumbs and Poultry com phone for a current price list Special diets are available for other birds if the eggs of ducks quail ete have been hatched Note cash with order is required with a delivery charge of 3 60 for orders less than 15 1 99 for orders over 15 and delivered free for orders over 16 The chicks are very messy animals and will scatter much of their food about the brooder where it will become contaminated with their droppings This wastage is inevitable so more starter crumbs or poultry corn will be required than might be imagined Because of the wastage it is difficult to be precise about the exact amounts of food to be ordered Food can be provided in sh
15. being weighed measurements should be carried out quickly Figure 3 overleaf shows the expected loss of mass as incubation progresses The loss should ideally fall on the solid line but some oscillation on either side of the line will not harm the embryo providing it is not too great If there is too little loss of mass ventilation should be increased and or humidity decreased If there is too much loss the ventilation is too high and should be reduced and or humidity increased 5 3 Checking development by candling Candling involves holding the egg in front of a bright light in a darkened room so that the light shines through the shell A simple way to do this is to cut a 4 cm hole in a piece of card and hold this over the bright light with the egg in front of the hole However there are ready made devices called candling or egg lume lamps All of the incubator manufacturers and suppliers listed in Table 1 sell egg lume candling lamps which consist of a lamp in a hand held holder with viewing window and push button operation Prices start at 7 83 for the Interhatch model E240 to 24 95 inc VAT for the standard model from Brinsea Products F150A 25 Figure 3 Graph of ideal loss of moisture from incubating eggs 15 Hy ds 2 a UN z iJ E y e F g Es E y v j b EX 5 T E i3 y E a iq B Y id Li 10 20 30 40 50 60 70 80 90 96 100 Incubation time COMMERCIAL There are a
16. falling through the hole There is a thermostat temperature adjustment is by a small easily accessible screw on the lid There is a red warning light The lid also has one ventilation hole The screw on the lid is turned by hand clockwise to increase and anti clockwise to decrease You do not need a screwdriver The heater light flashes when the temper ature is stabilising 24 hens eggs Yes Viewed through the transparent base and lid slightly obscured by the cage surround ing the heater and fan 2 7kg 41 x 30 x 20 cm Hatched chicks have a maximum head height of 17 cm at the sides of the base The standing height is reduced to about 10 cm if they are standing beneath the heater cage Maino Enrico Adriano Italy Banbury Cross 114 00 ine VAT Rob Harvey 119 99 inc VAT delivery Hatch it Incubators 90 00 ine VAT P and T Poultry 104 99 inc VAT Wheatcroft 0032 115 00 inc VAT A good incubator for school use It is easy to clean and store t comes with an instruction sheet which is translated from the Italian into a quaint English To replenish the water you have to take off the lid but as this will be for a very short time fluctuation in humidity and temperature will be slight It provides good views of hatching chicks The importer says that this model can also be used as a brooder once all the eggs are hatched because the temperature can be reduced to one appropriate for that purpose All the suppl
17. height this is clipped together so that the diameter of the brooder can be increased as the chicks grow n size Initially the diameter should be between 50 cm and 1 m for around one dozen chicks alternatively work on providing an area of 18 cm per chick Each week the area enclosed by the cardboard is enlarged If the brooder is on a table to allow small children to observe the chicks it is a good idea to cut a large hole in the cardboard and cover this window with a sheet of transparent acetate of the type used with overhead projectors igure 6 A d i y brooder CYUNDER OF CARDBOARDISTIFF PAPER 30 400m LARGE SHEET OF UGHT AS A HEAT SOURCE CLAMP AND STAND ML OBSERVATION WINDOW PAPER COVERED WITH CLEAR a ACETATE SHEET A SOURCE OF HEAT AN INFRA RED LAMP For newly hatched chicks the size of the brooder should be such that they cannot stray far from the heat source As they grow older they should be able to move away from the heat if they need to Cardboard boxes of increasing size as the chicks develop might also be used A suitable heat source for the brooder is required and this is ideally an infra red lamp which is suspended over the enclosure If you have borrowed an incubator from the same source you may also be able to borrow a complete brooder or just a heat lamp It may be possible to borrow a lamp and holder from a local secondary school science department so a few
18. hens eggs Semi automatic The eggs can be turned from the outside of the incubator by moving a knob connected to the egg tray This moves the tray sideways and as the separators remain still the eggs are turned The eggs are rotated by about 45 See Comments below for details of a fully automatic turning version The chicks are partially obscured by the fan and heater housing Maximum headroom for the chicks is 11 cm 3 7kg 37 cmx 25 cm x 29 em Novital Ascott PY283 109 99 inc VAT Dog Health C24 134 99 inc VAT delivery Interhatch ES17550 108 37 inc VAT delivery P and T Poultry 108 99 inc VAT An easy to use incubator The mercury thermometer is held in position in the clear rigid cylindrical plastic case by two springs which fall out if the case is opened quickly The case has a section which acts as a magnifying glass and this must be positioned over the reading scale of the thermometer This has a thick red line indic ating 100 F and there are two finer red lines one above and one below this There is no indication either on the thermometer or in the instructions as to the significance of these lines The temperature is adjusted by turning a recessed screw clockwise to inc rease and anti clockwise to decrease the extent of the turn needed to produce the required change has to be found by trial and error A small green light in the heater housing flashes as the temperature is stabilising
19. inc VAT Intethatch 512200 246 46 inc VAT P and T Poultry 179 99 inc VAT Solway 1130 279 94 inc VAT Wheatcroft 0017 248 19 inc VAT A similar design to the Hatchmaker but with a greater capacity and automatic egg turning the latter making it a preferable model for schools The observation window is larger than for the Hatchmaker but still provides only restricted viewing It is import ant to remember to tum off the automatic turning at the time of hatching there have been reports of injuries to birds caused by the moving platform All plastic construc tion so it is easy to clean out All the suppliers will accept orders on official school order forms Please sce note about delivery costs in section 4 2 14 Covatutto 7 Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A very small still air incubator moulded from polyurethane giving good thermal insulation The incubator has a bright yellow circular base and transparent plastic removable dome Heat is provided by a 15 W golf ball light bulb heater fixed in a black holder in the centre of the dome Humidity is provided by adding water to two troughs in the base unit Small ventilation holes are pierced into the clear dome The mercury thermometer is inside a plastic case and this slots into a hole in the dome Eggs are placed on a moulded platform
20. inside the base The bulb of the thermometer is above the position of the eggs Recessed requiring a screwdriver to adjust within a depression in the black lamp holder on top of the clear dome The heater bulb flashes when the temperature is stabilising 7 hens eggs No Viewed through clear plastic dome View partially obscured by lamp holder 0 95 kg Diameter 25 cm height 24 cm Hatched chicks have a maximum head height of 7 cm at the centre of the base 9 cm at the edge The standing height is reduced if the chicks are standing on eggs Novital Ascott PY293 49 99 inc VAT Dog Health c7 59 99 inc VAT delivery Domestic Fowl Trust INI2 59 99 inc VAT Interhatch E517400 40 38 inc VAT delivery P and T Poultry 48 99 inc VAT A very small incubator The mercury thermometer is held in position in the clear rigid plastic cylindrical case by two springs which fall out if the case is opened quickly The case has a section which acts as a magnifying glass and this must be positioned over the reading scale of the thermometer This has a thick red line indicating 100 F and there are two finer red lines one above and one below this There is no indication either on the thermometer or in the instructions as to the significance of these lines The temperature is adjusted by turning the recessed screw clockwise to increase and anti clockwise to decrease but the extent of the turn needed to produce the
21. on the top of the yolk This will how ever possibly cause some distress to pupils as the embryo although at this stage not recognisable as a young bird will inevitably die once the egg is opened Teachers must be very sensitive to the emotions of their pupils and consider whether this procedure is advisable or necessary because other mat erials are available to show the embryo within the egg In any discussions on this it might be helpful to point out that people who prefer free range eggs may at some time have eaten some which were fertile Once the eggs are incubated and the embryos become more recognisable as birds opening the eggs to examine them will certainly distress many pupils In these circumstances it would be most unwise for teachers to consider proceeding with such investig ations and they must discuss the issue with their pupils before starting In any event teachers must not open eggs containing live embryos which have been ncubated for more than ten days this is a legal requirement 4 FUNCTIONS OF THE ALLANTOIS One aspect of the development of the chick within the egg which is not easy to investigate is nevertheless quite vital for its survival This is the formation of an outgrowth from the embryo called the allantois see Figure 13 This enlarges quickly it grows over the embryo and lines much of the inner surface of the egg It functions as a gas exchange surface Figure 13 Dev
22. phone calls may be very cost effective 31 LAMPS FROM VARIOUS SUPPLIERS If it is impossible to obtain something suitable on loan a number of suppliers sell infra red lamps and holders For example Griffin Education supplies an infra red heater consisting of a lamp protective shield and built in reflector HCT 601 020B 53 85 spare lamp HCT 605 010D 10 50 both excluding VAT Brinsea Products and other suppliers sell an infra red brooding lamp 150 W or 250 W for 49 95 ine VAT igure 7 Infra red heat lamp SUSPENDING THE HEAT SOURCE OVER THE BROODER AN ANGLEPOISE LAMP AS A HEAT SOURCE BROODER TEMPERATURE INITIALLY 35 C ADJUST LAMP HEIGHT TO VARY THE BROODER TEMPERATURE FOOD FOR THE YOUNG CHICKS 009 Some means will be needed to suspend the lamp over the brooder It has been suggested that a stand used to measure a child s height might be employed for this purpose Alternatively a retort stand with a heavy base and clamp can be used These may already be available or might be borrowed from a local secondary school science department If they need to be bought they are sold by school science equipment suppliers If using the heater above the reflector should be suspended using the chain provided and not dangled by the flex An alternative possibly cheaper though less satisfactory source of heat is to use an anglepoise lamp This is not designed to be used with higher wattage bulbs
23. small or too large for the stage of development reached there will have been respectively too little or too much evaporation of water from the egg If the air space is too small ventil ation should be increased and or humidity decreased If the air space is too large the ventilation is too high and should be reduced and or humidity ncreased Candling should be performed as quickly as possible to avoid excessive chill ing of the eggs If candling reveals that eggs are infertile or the chicks have died the eggs should be removed from the incubator 5 4 Incubating the eggs of birds other than chickens A variety of birds other than chickens can be incubated and hatched if supplies of their fertile eggs become available These include bantams ducks geese guinea fowl pea fowl pheasants quail and turkeys Note that only eggs of domesticated species are to be studied For sources of supply see section 3 We do not however recommend that any of the above should be chosen by schools new ro incubation experience should first be gained with hens eggs The technique of incubation described for chickens is essentially the same for other eggs Obtaining reliable figures for incubation times and temperatures applicable for different birds is not all that easy Different incubation periods and temperatures are quoted by different authorities and as discussed on page 23 the design of the incubator will also influence the
24. the head office or look at the web site bookings section to find out if there is a franchise near you The price for the service starts at 225 There are of course many other sources of fertile eggs the problem some imes is locating them Yellow Pages can be consulted for local supplies look under Egg Merchants Egg amp Poultry Packers Farmers and Poultry Farmers remember to specify fertilised eggs when you ring Just as this guide was about to be printed we discovered a very usefull and extensive list of suppliers of fertile eggs on the Brinsea Products web site This list is buried away in the information about a new incubator which appeared on the market too late for us to consider for this guide the R Com digital incubator To find the list go to the Brinsea UK web site scroll down to the Incubator Packs section click on the R Com digital incubator and click on the link to the list The URL for this list of egg suppliers is currently www brinsea co uk uk products rcomeggs html Local farms are often a fruitful source including some city farms in urban areas The National Federation of City Farms and Community Gardens produces a listing of establishments contact the NFCFCG web site to find out if there is a city farm near you Kortlang and Kortlang supplies fertile duck eggs The minimum order is one dozen eggs and delivery an additional charge is arranged via Amtrak Check wh
25. to adjust within a depression in the top cover Indicator lamp displays when the heater is operating 36 hens eggs None Viewed through a double glazed acrylic window in cover only 10 5 x 10 5 cm 3 5 kg 36 x 36 x 20 cm high Hatched chicks have a maximum headroom of 13 cm and less than this if standing on eggs Brinsea Products Ascott PY33 139 45 inc VAT Banbury Cross 110 00 inc VAT Brinsea Products CHOLA 154 95 inc VAT Domestic Fowl Trust ING 154 95 inc VAT Hatch it Incubators 127 00 inc VAT Inter Hatch ES12100 131 79 inc VAT P and T Poultry 125 99 inc VAT Solway feeders 1126 149 95 inc VAT Wheatcroft 0015 132 95 inc VAT An effective and relatively inexpensive incubator which however is not ideal for schools because of the absence of automatic egg turning and the restricted view of the eggs For automatic turning see the Polyhatch incubator The incubator must be opened to add water to the compartments beneath the egg tray The Hatchmaker could also be used along with another incubator as a hatcher to which eggs are transferred just before the chicks emerge Easy to clean out AI the suppliers will accept orders on official school order forms Please sce note about delivery costs in section 4 2 a Octagon 10 Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments
26. 12 eggs and a maximum of 24 eggs will be appropriate See section 4 2 for the capacity of incubators currently on sale WHAT S THE BEST TIME OF YEAR TO INCUBATE EGGS WHAT ABOUT CARING FOR THE EGGS AND CHICKS AT WEEKENDS WHAT WILL BE NEEDED AND ARE THERE SUFFICIENT FUNDS AVAILABLE WHAT IF SOMETHING SHOULD GO WRONG There are a number of advantages in starting your incubation project in the spring Eggs obtained from free range hens or from birds kept in natural light are more fertile and their hatchability is highest at this time of year Fertile egg suppliers may only have eggs available for a limited period beginning in March But if you are borrowing equipment remember that others will prob ably also want to incubate in the spring so competition will be higher then Avoid incubation during the winter months if at all pos types used in schools may not be able to maintain constant conditions because of drastic falls in temperature at night or weekends if the heating system does not operate continuously Involvement of the school premises or site manager is essential Access to the school premises at weekends will be needed some of the time Even if the incubator has an automatic egg turner or the premises manager can be persuaded to turn the eggs at weekends the chicks will need attention once they have hatched Arrangements might be made to transport a non turning ncubator home at weekends but this will depe
27. 22 ESTABLISHING THE The correct temperature for the incubation of a chicken s egg is 37 5 C at the CORRECT TEMPERATURE centre of the egg Follow the manufacturer s instructions about setting the temperature In some still air incubators there is quite a large temperature gradient inside With some models in which the thermometer is situated at the top where the air is warmer the recommended temperature setting may appear to be too high However such a setting allows for the cooler correct ncubation temperature lower down INCUBATION TEMPERATURE In most incubators the thermometer should be positioned where the top of the OF 38 39 5 C eggs will be Manufacturers recommended temperature settings could there fore lie anywhere between 38 C and 39 5 C 100 5 103 F In normal ncubator operation temperatures may fluctuate slightly but they should not be allowed to pass outside this range As the eggs develop the embryos will give off some heat and this may require you to alter the thermostat setting slightly to decrease the temperature Some instruction books eg those provided by Novital for Covatutto models give temperatures only in degrees Fahrenheit For incubation temperatures of the eggs of species other than chickens refer to the information in section 5 4 AVOIDING PUPIL Once the correct temperature setting for the type of eggs to be incubated has INTERFERENCE been achieved it is wise to tape over th
28. D EGGS TOO QUICKLY CONSIDER THE SITING OF THE BROODER USING A PURCHASED BROODER The yolk sac attached to the developing embryo inside the egg see Figure 13 in section 10 is normally absorbed during the final days of incubation Occasion ally a chick may hatch with its yolk sac hanging out Its survival is endangered and the chick should be isolated The yolk sac may naturally be reabsorbed but this takes time and the chick must be kept in clean conditions to help prevent infection If given time reabsorption does not happen or the chick is obviously in distress it should be humanely destroyed as should any chicks with other deformities or evident illness see information in section 8 Any animal which is isolated and later returned to the brooder may be attacked by other chicks It is best if the animal is reintroduced at a time when food is given to all the chicks so that attention is diverted away from the newcomer A feature of the development of the chick is the formation of an external pouch and membranes called the allantois Waste materials are deposited in this structure The remains of the allantois and its wastes are sometimes seen still attached to the rear end of the hatched chick This is not something to worry about The remains will dry up and drop off Even with eggs set on the same day there can be quite a lot of variation in the time they take to hatch and so it is important to wait at least 72 hours before dis
29. E STUDYING EGGS and CHICKS There can be few more exciting activities in schools than incubating eggs and then watching the hatching process and early development of the birds Obv iously such activities will support aspects of work in the Programmes of Study at Key Stages 1 2 and 3 of the Science National Curriculum Several aspects of the work will provide a stimulus for further studies in maths English PSE etc Some suggestions are given below to provide ideas of the possibilities See also section 11 8 10 1 A study of reproduction and development Work on the incubation and hatching of chicken or duck eggs can be a part of a wider study on this topic in several animals including small mammals This broader approach is useful because it will allow the various important points of similarity and difference in the reproductive processes of different animals to be emphasised Thus in most fish and amphibia there is external fertilisation and development outside the body in the water in most mammals all stages of reproduction are completely internal The reproduction of the chick falls mid way between these two extremes with fertilisation and initial development which are internal followed by an extended period of external development which places few demands on the mother other than her contribution as a heat source There is clearly more protection inside the egg for a developing chick embryo than for young fish or amphib
30. E HUMIDITY LEVEL MONITORING LOSS OF MOISTURE FROM THE EGGS WEIGHING EGGS REGULARLY VIEWING THE EGG AGAINST A BRIGHT LIGHT COMMERCIAL CANDLERS With Octagon incubators eggs can be turned without opening the incubator by tipping the entire unit from 45 on one side to 45 on the other side How ever do not worry about opening the incubator for a short time to turn eggs Although the temperature will temporarily drop the developing chicks will not be harmed after all a broody hen does not sit on the eggs all the time Some authorities claim that eggs should sometimes be turned clockwise and then counter clockwise If eggs in a manual turn incubator are turned an odd number of times each day they will not repeatedly spend each long night time period in the same orientation By the 18th day the eggs no longer need to be turned Follow the guidance offered by the incubator manufacturer Various author ities quote a wide range of suitable humidities but it is difficult to produce an exact humidity in the incubator and to measure it accurately Ensure however that the water tray never dries out completely and equally do not have a very humid atmosphere together with poor ventilation If the eggs are in an egg tray on a dish cloth or piece of hessian do not add water to the material to make it damp Also do nof spray the eggs daily with a mist of water although this has been recommended by some authorities
31. EGG As discussed in section 5 2 page 25 the natural loss of moisture from the dev eloping eggs can be studied and allow pupils to make measurements and plot graphs As moisture is lost the mass of the eggs will fall The loss of moisture is an essential feature of development and a fall of between 12 15 of the initial mass during the entire incubation period will normally be seen if the correct humidity in the incubator is maintained Such measurements at regular intervals can help to check that an appropriate humidity is being provided in the incubator Batches of rather than single eggs can be weighed at say 0 7 and 14 days this will increase the mass to be measured and help to increase reliability if your balance is not very accurate The ideal loss of mass say 12 can be calculated from the initial readings and used to plot a graph of expected mass at various times during incubation see Figure 3 page 26 The actual mass of the eggs can then be plotted alongside to check progress Figures of about 1 2 either side of the ideal readings are acceptable without the need to adjust the humidity of the incubator Again ensure that eggs are not removed from the incubator for too long when they are weighed 10 2 The structure of an egg Eggs are familiar to most people but it would be unwise to assume that because of this children will have appreciated the detailed structure of the egg or related this to the needs of the embryo
32. HUMANE KILLING PREPARING PUPILS TO COPE IF CHICKS HAVE TO BE DESTROYED USE OF A LOCAL VET OR THE PDSA DEALING WITH UNWANTED DISEASED or INJURED ADULTS As discussed in sections 1 and 2 unless a decision has been taken to keep the hatched chickens it is essential that plans are made in advance to find a suitable home for them To avoid doing this is irresponsible and humane destruction should not be used as a convenience It is also unacceptable to assume that local contacts will automatically be willing to take your animals and so present them with a fait accompli once the birds have hatched Firm arrangements must be made before incubation work commences There are often a number of people willing to accept small numbers of chickens and local farms are obvious potential homes See Yellow Pages under Farmers for possible contacts in rural areas In urban areas there are a number of City Farms The National Federation of City Farms and Community Gardens produces a listing of establishments refer to the NFCFCG web site if you would like to find out if there is a city farm near you If you have borrowed equipment for the project from a local source it is possible that you will be able to include the chickens when you retur the incubator Contacts in local teach ers centres and agricultural colleges may also be fruitful It should be noted that some of the farms may only be able to take birds when fully matur
33. IRABLE FEATURES OF AN EGG INCUBATOR It will not normally be possible to pick and choose so the most suitable model may not be available Older incubators often those most likely to be offered for loan may not possess features which have improved the efficiency of curr ent models and may not have been well maintained so hatching success could be reduced Automatic turning may not be provided so what will happen at weekends Will the capacity of the incubator match the number of eggs you had decided to incubate Older incubators which use an outdated wafer type thermostat which looks like bellows may exhibit unsatisfactory temperature fluctuations unless working at full capacity If this type of incubator is avail able for loan incubating more rather than less eggs is preferable but then you could have more adult birds on your hands Before going too far in setting up your project decide how much you are pre pared to alter your initial ideas and requirements Using a loaned egg incubator can be a bit of a lottery so here are some points to remember If in doubt it may be wiser to refuse the incubator offered Mf hiring look at the total cost for the time you will need the incubator Check for delivery costs deposits and insurance too Check on other items provided with the loan service for example items for brooding feeding and watering see section 6 2 If they are not supplied you will have to provide these facili
34. It Grow series Duck 0749661194 599 For younger children helps develop an understanding of the needs reproduc tion and growth processes of ducks Ducks D Tomlinson 187358024X 7 99 A chatty readable book which provides interesting facts about all manner of ducks aT 2 BOOKS out of print Several useful titles are no longer available for purchase but may be easily accessible in libraries or even for sale on e Bay or Amazon web sites A selection of the titles is given below FROM DORLING Egg 0751351032 KINDERSLEY Over 200 excellent photographs with accompanying text illustrating the hatch ing of animals from their eggs It covers a wide variety of birds and also fi amphibia reptiles molluscs and insects Excellent material Shaped Board Books Chick 1859481027 A bright and colourful book in the shape of a chick illustrating the animal with many full colour photographs FROM DRAGON S WORLD Nature s Treasures series Ducks 1850282897 A well illustrated general information book on a variety of ducks FROM LERNER Natural Science series PUBLICATIONS Inside an Egg S A Johnson Hdbk 0822514729 Pbk 0822595222 An excellent well illustrated guide to chick development FROM TFH PUBLICATIONS Chicks and Ducks as Pets 0866224319 An introductory book written for pet owners at home FROM WEIDENFELD amp Little Book of Ducks 0297832433 NICHOLSON An illustrated book for young children 3 WALLCHARTS and PHOTOGRAPHS
35. JOURNAL of the ASSOCIATION for SCIENCE EDUCATION PRIMARY SCIENCE REVIEW Produces a wide range of resources ranging from an 8 page booklet Egg Production up to 30 copies free to The Egg File a comprehensive resource file for students of design and technology at GCSE 1 free copy per school There are resource banks which can be downloaded from its web site www eggsedu org uk Chicks in school L Pocock Volume 66 No 234 September 1984 Page 79 A collection of ideas for practical activities with eggs and chicks An eggciting idea Kay Rosie No 1 Summer 1986 Page 6 Driving us quackers Kay Rosie No 4 Summer 1987 Page 7 Accounts of an infant school teacher s success with incubating chick and duck eggs 49 12 ADDRESSES ASCOTT SMALL HOLDING The Old Creamery Four Crosses Llanymynech SY22 6LP SUPPLES LTD Tel 0845 130 6285 Tel 0870 774 0140 E mail sales ascott biz Web site www ascott biz ASSOCIATION FOR College Lane Hatfield AL10 9AA SCIENCE EDUCATION Tel 01707 283000 Fax 01707 266532 E mail info ase org uk Web site www ase org uk ATP INSTRUMENTATION Toumament Way Ivanhoe Industrial Estate Ashby de la Zouch LE65 2UU Tel 01530 566800 Fax 01530 560373 E mail sales atp intrumentation co uk Web site www atp instrumentation co uk BANBURY CROSS Eden Hall Southam Road Banbury OX16 IST VETERINARY FARM Tel 01295 758504 Fax 01295 758418 SUPPLIES E mail clivemadeiros aol com www banb
36. January 2006 L71 Incubating and Hatching Eggs Incubating and Hatching Eggs SCHOOL SCIENCE SERVICE GUIDE L71 Ber 41 42 54 52 53 54 6 1 62 63 64 6 5 10 1 10 2 103 104 10 5 10 6 10 7 10 8 10 9 10 10 n 12 L71 Incubating and Hatching Eggs Contents Introduction Before you start Sources of eggs Incubators Borrowing or hiring an incubator Purchasing an incubator Incubating eggs Setting up an incubator Incubating chicken eggs Checking development by candling Incubating the eggs of birds other than chickens Hatching eggs and rearing the chicks The chicks hatch Using a brooder Feeding and watering the chicks Keeping adult chickens Rearing birds other than chickens Handling and sexing Dealing with unwanted diseased or injured adults Health and safety Studying eggs and chicks A study of reproduction and development The structure of an egg Science from eggs The chicks hatch Observing chicks Recording growth and development Investigating feeding Investigating heat loss Working with feathers Studies of chick behaviour Sources of information and learning materials Addresses This guide is a revision of CLEAPSS guide L71 originally published in March 1997 Strictly confidential circulation to Members and Associates only This guide combines material from the first edition of CLEAPSS guide L71 and information originally published in the Guidelines series by the I
37. LEA Centre for Life Studies hence the g on the front cover Following the closure of the Centre the School Science Service has acquired the copyright of all the CLS publications CLEAPSS 2006 School Science Service Brunel University Uxbridge UB8 3PH Tel 01895 251496 Fax 01895 814372 Web site www cleapss org uk WHAT THIS GUIDE IS ABOUT TO INCUBATE OR NOT TO INCUBATE PROMOTING A RESPECT FOR LIFE L71 INCUBATING and HATCHING EGGS INTRODUCTION Anyone who has successfully incubated eggs in a school will recall all the excitement and enthusiasm shown by both pupils and staff patiently waiting like expectant mothers for the hatching day on which the small birds would peck their way out into the outside world Such a project will provide a focus for a whole variety of both scientific and creative activities It can provide support for aspects of work in several areas of the National Curriculum including science mathematics and English as well as PSE art and so on Some suggestions for the types of activities that are appropriate for pupils in key stages 1 2 and 3 are given later in section 10 Studying Eggs and Chicks Careful planning and an appreciation of what will be involved in the project are of course needed to avoid problems Guide L71 outlines the arguments for incubating eggs and identifies the diffic ulties and other points to consider before starting It includes a discussion of sourc
38. M OXFORD EDUCATIONAL RESOURCES 6 VIDEOS FROM DOMESTIC FOWL TRUST Biosets The Chick Embryo 233 How Animals Reproduce From Egg to Embryo ZIG Biosets are strips of 8 photomicrographs of views taken through a microscope they are observed using a special Bioviewer They are more suited for pupils work in lower secondary schools Minimum available Box of 10 for 21 80 excluding VAT For use with Banta Bioviewers 7 50 each discount available on 10 or more Chick Embryology AV4 24 01 26 colour slides produced by Oxford Scientific Films charting chick devel opment in some detail Rather technical only appropriate for secondary schools Window into a Nest AV35 12223 24 colour slides produced by Oxford Scientific Films which supports work on chicks by illustrating the rearing of blue tits in a more natural setting Poultry at Home 15 95 Incubation 15 95 Keeping Ducks 15 95 Poultry Matters 14 95 Although not seen by CLEAPSS these videos may be useful for those schools wishing to rear adult chickens or ducks and for those that might value some support in their incubation project Note that the video prices include VAT Some incubator suppliers also produce videos Check with individual suppliers for their current listing 7 MULTI MEDIA MATERIALS FROM BRITISH EGG INFORMATION SERVICE 8 ARTICLES FROM THE JOURNAL of the ASSOCIATION for SCIENCE EDUCATION SCHOOL SCIENCE REVIEW FROM THE
39. allow dishes but these can be overturned or fouled by the chicks and are not recommended It is better that food is provided in one or more hoppers A local pet shop may have what you need but suppliers sell cheap plastic 1 kg capacity feeders eg Hatch it Incubators has a 10 inch feed trough for 4 25 You can however manufacture food hoppers for yourself from washed out tin cans The top is cleanly removed so that there are no sharp edges A cut is then made in the side of the can with a hacksaw about one third up from the base Using tin snips or strong scissors make small vertical cuts at each end of the cut and with forceps or pliers fold the sharp cut edges inside the can Then press the can inwards above the cut to produce the feeding hole in the hopper See Figure 8 Keep the hoppers regularly filled with crumbs or corn Figure 8 A home made food hopper ADDITIONAL GREEN FOOD PROVIDING SUPPLIES OF DRINKING WATER USING PET SHOP WATER FOUNTAINS A little green plant material such as chopped greens lettuce cabbage water cress or chickweed can be provided after the first week Water must be constantly available as the chicks drink regularly Initially they may need to be encouraged to drink by attracting their attention to the water source This can best be achieved by placing the water container on top of a piece of aluminium foil If this fails dip the chicks beaks in the water Open dishes of water shoul
40. carding unhatched eggs The remains from hatched eggs should be removed from the incubator as soon as possible and these together with unhatched eggs should be disposed off hygienically see section 9 The incubator should then be thoroughly cleaned out and disinfected see information in the footnote on page 22 6 2 Using a brooder An incubator should not be used to house chicks once they have hatched rested and their feathers dried out A simple brooder needs to be bought or constructed to house the chicks and keep them warm because of their small size chicks have a relatively large surface area from which to lose heat A brooder is some form of enclosure with an overhead heat source The brooder must be sited away from draughts and placed on a large sheet of paper preferably nor newspaper Some authorities suggest that the floor of the brooder should then be covered with a layer of good quality white wood shav ings not sawdust available from pet shops or more economically in large bales from specialist suppliers see Yellow Pages under Sawdust and Shav ings This however is not essential and does add to the mess that must routinely be cleared up Chicks suffer from cramp if kept on a cold surface Ideally they should be reared off the floor on a wooden surface Wherever the brooder is placed it is prudent to protect the surface by covering it with polythene It may be necessary to cover the brooder with wir
41. ce philipharris co uk Web site www philipharris co uk Palady Spring Old Andover Road Newbury RG20 OLS Tel 01635 230238 Fax E mail sales hatchitincubators com Web site www hatchitincubators com Rob Harvey Specialist Feeds Kookaburra House Gravel Hill Road Holt Pound Farnham GU10 4LG Tel 01420 23986 Fax 01420 23078 E mail rob robharvey com Web site www robharvey com PO Box 1420 Kiln Farm Milton Keynes MK19 6ZH Tel 01908 563338 Fax 01908 262654 E mail sales insectlore co uk Web site www insectlore europe com 27 Whittington Way Old Whittington Chesterfield S41 9AG Tel 01246 264 646 Fax 01246 268344 In December 2005 this company had no e mail and no web site Shepway Kennington Rd Willesborough Lees Ashford TN24 ONS Tel 01233 623431 Fax 01233 624783 In December 2005 this company had no e mail or web site Abbeygate Road East Road Cambridge CBI IDB Tel 0845 120 4776 Fax 0800 783 8648 E mail Via web site Web site www ldalearning com The Grange Heyford Lane Stowe Hill NN7 4SF Tel 07974 310 860 Fax 01327 349242 E mail info livingeggs co uk Web site www livingeggs co uk 2 Pound Hill Great Brickhill MK17 9AS Tel 01525 261606 Mobile 07939 020686 E mail ivan mearsandboyer co uk Web site www fertilehatchingeggs co uk The GreenHouse Hereford Street Bedminster Bristol BS3 4NA Tel 0117 923 1800 Fax 0117 923 1900 E mail admin farmgarden org uk Web site www farmgarden org u
42. d a much lower success rate at hatching even zero may be exper ienced Eggs may be tumed by hand either because the incubator has no automatic turn facility or because pupils will do this during the day while the incubator tums the eggs at night and at weekends Manual turning of eggs needs to be carried out at least twice preferably three times and ideally five imes a day including at weekends If the incubator has an automatic tum facility this relieves schools of the problem For non automatic incubators other than the Brinsea Octagon types mark each egg lightly with an X in pencil on one side and O on the opposite side as the eggs are added to the incubator Also write the date if different batches of eggs will be added to the incubator later The degree of turn varies from 45 through 180 around their long axis not end to end At each turn move the eggs so that the X and O marks are alternately visible Turning is best achieved by rolling cach egg using the finger tips into an adjacent space If the incubator is very crowded it may be necessary to remove some eggs at one end so the other eggs can be rolled into the space made available The removed eggs are then placed in the space created after rolling Hands should be warm to prevent chilling the eggs 24 OCTAGON INCUBATORS TURN EGGS BY MOVING THE ENTIRE INCUBATOR TURN EGGS AN ODD NUMBER OF TIMES STOP TURNING EGGS ON DAY 18 ADJUSTING TH
43. d be avoided because of the problems of fouling and some form of drinking fountain is preferable Provide two drinking fountains in the brooder to ensure a constant supply of water in case of mishaps Drinking fountains can be purchased from pet shops or specialist suppliers such as Hatch it Incubators which sells a 1 litre plastic drinker for 3 00 By using water containers designed for bird cages as shown in Figure 9 overleaf the problems of fouling by the chicks can be reduced An easily constructed design of water fountain is shown in Figure 10 overleaf If you do not have a suitable shallow container again ask a local secondary school science department if it can spare a glass or plastic Petri dish or two Even this design of drinking fountain is still likely to become contaminated by the chicks and will require regular cleaning 33 Figure 9 Using bird cage water cont ers 4 BIRD CAGE DRINKING FOUNTAINS RUBBER BANDS OR SELLOTAPE Figure 10 A home made water fountain CHICKS MESSY HABITS LOOKING AFTER CHICKS AT WEEKENDS YOUNG BIRDS MAY NEED TO BE KEPT FOR AROUND 6 8 WEEKS BEAKER ORAM JAR SHALLOW CONTANER so PETRI DISH Because the chicks are so messy they will need to be cleaned out at least daily with a fresh sheet of paper and wood shavings if used to line the floor of the brooder Food and water containers will need to be similarly cleaned out and replenished Teac
44. drop is too great it is quite likely that the incubator will be unable to maintain a steady temperature It is therefore best to avoid incubating eggs during the coldest months if temperature regulation is likely to be a problem Although an incubator might be taken home every night this is highly inconvenient Also mechanical damage to the developing embryos caused by bumping the incubator in transit may cause severe damage to delicate membranes and organs and so the regular movement of an incubator is nof recommended SETTING UP The first task is to clean and disinfect the incubator as appropriate The inc IN ADVANCE ubator should be set up at least 48 hours before eggs are introduced to enable the correct temperature and humidity to be established and to check on the normal functioning of the thermostat Some manufacturers give specific inst ructions about cleaning their particular models and these should be followed The most appropriate disinfectant to use is probably ASAB from Griffin GASAB 1 litre 21 14 but this is obviously expensive and only available in large volumes Another disinfectant Virkon could be used though it does attack metal and this is available from Philip Harris in 50 g sachets A58543 1 91 or more economically in 500 g tubs ASSSSS 16 48 Local pet shops may also sell VirKon Several of the suppliers of incubators sell suitable disinfectants and this could be purchased when ordering other items
45. ducational suppliers known to CLEAPSS Timstar Laboratory Suppliers mentioned in the previous edition no longer supplies fertile hens eggs The Domestic Fowl Trust will supply and deliver fertile hens eggs for a limited period from the beginning of March to any mainland UK address The cost is 1 per egg and the delivery charge is 14 50 2005 prices Ivan Mears supplies fertile eggs supplier s choice eggs cost 5 per dozen eggs with blue or green shells 10 per dozen and ones that are sex linked from white males and brown females also 10 per dozen Eggs can be collected or delivered 6 charge per dozen next day delivery The supplier will also take back hatched chicks It is best to speak directly with the supplier rather than use the web site P and T Poultry also supplies pure breed fertile eggs either as quantities of a particular breed or mixtures of breeds Light Sussex and Maran eggs can be provided throughout the year all others in a limited period from March Costs are 8 9 for 6 delivery extra unless the eggs are ordered at the same time as an incubator Wheatcroft also supplies standard eggs from March onwards as well as the eggs of specialist breeds The cost of the standard eggs is 12 per dozen including postage There is an organisation established in January 2005 called Living Eggs This will provide all the materials needed for the hatching of eggs and oper ates on a franchise basis Contact
46. e and that others will only take hens Some will accept both males and females but it must be realised that only the females which lay eggs are usually of interest and the males may be killed for food In all cases contacts must be made well in advance to determine whether there is space available for your chickens or whether certain conditions will be imposed As a result of chicks hatching with some deformity such as an external yolk sac which has not been reabsorbed developing an illness or being injured in an accident humane destruction may be required In schools the only acceptable method is to induce unconsciousness with carbon dioxide gas and then use an overdose to kill the animal This obviously poses severe problems for most establishments Details of what is involved are included in our guide L52 Small Mammals Traditional mechanical methods of killing chickens involving wringing their necks although quite humane when practised by an expert are clearly inappropriate for use in schools Pupils may be very distressed when deformed chicks are hatched and have to be humanely destroyed Teachers should prepare pupils in advance for the possib ility that something might go wrong Where facilities are not available for humane killing the animal should be taken to a local vet but this will usually incur a fee The location and business hours of a suitable vet should be identified in advance If there is a local PDSA treatm
47. e incubator have the facility to turn the eggs automatically The eggs must be turned regularly and although pupils can do this manually during the day it is helpful if eggs are also turned at night and essential at weekends if a reduced success rate is to be avoided Without automatic egg turning someone will have to come in to school at weekends or the incubator must be taken home During transport damage may be caused to the delicate organs and membranes of the chicks within the developing eges CJ Does the incubator have an appropriate egg capacity Some models are very large while others are almost too small In deciding which incubator is most suitable for your needs it is important not to underestimate the capacity which will be needed but again do remember that the more eggs you hatch the greater your problem may be in finding all the birds a home How heavy is the incubator This could be important if you have to take it home to tum eggs at the weekend Large and heavy incubators could create storage problems Will the incubator be immediately available There may be a delay in the supply of some incubators which are imported or cannot be manufactured fast enough at times of peak demand We would suggest that before placing an order obtain in writing a statement of how long it will be before the item will be delivered How much can be afforded It could be a big mistake simply to buy the cheapest incubator it may n
48. e netting at some stage to prevent the birds escaping A fire safety guard for children has proved useful here A purpose built brooder called the Cosy lamp is available see Figure 5 over leaf This has passed CLEAPSS electrical tests and is manufactured and supp lied by Brinsea Products HA02A 79 95 inc VAT and also sold by several other suppliers including Interhatch The brooder uses ordinary lamp bulbs operating at reduced voltage to provide a source of heat the casing does not become too hot The base area of the unit measures 500 mm x 500 mm and it stands directly on the floor or table top though it could be suspended for brooding birds much larger than chicks such as goslings The chicks can walk out through an entrance hole so it will be necessary to provide an outer perimeter barrier to prevent the animals straying For those using the Octagon 20 incubator Brinsea Products sells a reari module A030 82 70 inc VAT also sold by other suppliers which cons a plastic enclosure on top of which is placed the Octagon 20 heating unit g ts of 30 igure 5 sea Products Cosy lamp brooder A HOME MADE BROODER E Lae It is however unnecessary to incur the expense of purchasing a ready made brooder though some outlay on a heat source will probably be required An effective design for a brooder shown in Figure 6 is a circle made out of a long length of cardboard or stiff paper about 30 40 cm in
49. e of the eggs and brood In advance identify the location of a local vet and the hours when the surgery is open in case you need to make arrangement for urgent attention to a chick n distress Think carefully about whether you and the children will be able to cope if problems arise eg the hatching of a deformed chick You will need to prepare pupils for the possibility that this might happen To help in the planning of your incubation project Figure 1 gives an indica tion of the timing of various events This assumes that the project will start in the spring for work at other times of the year make appropriate adjustments An incubation project time line Check that a Order equipment equipment has Sometime in tobe purchased arrived Are loan June Chicks Find homes for items and homes Apri 30th delivered to chickens as forchickens sill April th Chicks to new home i necessary ok Seteggs brooder not being kept If borrowing Place order for April tst Apri 2h End of May End of June equipment start fertie eggs to be Collectloan Eggs hatch Chicksstant Chickens moved to making arrange delivered say equipment to grow adult outdoor area for ments now for on Apri Bih plumage long term rearing next spring OBTAINING FERTILE CHICKEN EGGS TRACKING DOWN LOCAL SOURCES USE YELLOW PAGES WEB SITE LIST OF EGG SUPPLIERS CITY FARMS FERTILE DUCK EGGS OURCES OF EGGS There are a few commercial e
50. e temperature control to dissuade pup ils tweaking the knob If possible position the incubator so that the temper ature control is hidden against a wall GUARDING AGAINST Consider plugging the incubator into an audible alarm unit this will indicate POWER FAILURE OR if there is a power failure for any reason Even with such a device it is a good DISCONNECTION idea to affix a PLEASE LEAVE ON sign to the mains plug and so avoid accidental switching off by cleaners or other members of staff It is also sens ible to keep a temperature record card logging readings every morning and evening This is an easy way of checking that the incubator is functioning correctly and the card could also be used for a record of egg turning if this is being done by hand ENSURING ADEQUATE A suitable humidity must be maintained to prevent the eggs drying out too HUMIDITY quickly as well as ensuring they lose sufficient water All incubators have one or more water containers trays or troughs which should be kept topped up with water to maintain an appropriate humidity according to the manufactur er s instructions Use hand hot 39 C water to prevent the temperature in the ncubator dropping too dramatically when refilled Do not move the incubator while containing water In some incubators a piece of cloth may be needed to act as a wick Too much humidity at the wrong time is just as bad for a developing egg as too dry an atmosphere
51. e to have in the incubator at the same time eggs that were set on different days while some eggs are turned on the rollers others can be hatched in the space beneath Viewed through the Perspex cover giving a completely unobstructed view Model 136 7 kg Model 137 11 kg Model 136 39 x 36 x 20 cm high Hatched chicks have a maximum headroom of 16 cm but less than this if standing on eggs Model 137 50 x 50 x 27 cm high Hatched chicks have a maximum headroom of 16 cm but less than this if standing on eggs Curfew Incubators Curfew Incubators but see comments above Both are sturdy reliable incubators with provision for the observation of eggs and chicks that is excellent The absence of automatic egg turning in 136 makes this a less attractive incubator for schools than the 137 model The incubator is heavier than others but still portable Curfew models are more difficult to clean out than other incubators 18 MPS 12 Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A small moving air incubator moulded from polyurethane and shaped like a squashed oval it has a coloured opaque base and a removable translucent domed lid Visibility is poor The eggs are warmed by the heating element in the lid Eggs are put into the coloured base there is neither rack nor dividers and the eggs are turned by hand T
52. ea Products has an audible alarm ETVO 20A at 164 95 inc VAT exc delivery Hatch it Incubators supplies a temperature alarm module T20 at 136 00 23 ENSURING ADEQUATE VENTILATION ENSURE THAT VENTILATION HOLES ARE NOT COVERED PRE WARMING EGGS PRIOR TO INCUBATION LINING EGG TRAYS WITH HESSIAN DO NOT SET EGGS ON A MONDAY TURNING THE EGGS EACH DAY MANUAL TURNING MARK THE EGGS WITH AN X AND AN O The eggs must have a suitable flow of air to supply enough oxygen for the embryos to develop and to remove the carbon dioxide produced The ventila tion will however also affect both the humidity and the temperature a high ventilation rate will carry more moist warm air out of the incubator A fine balance of all three inter related factors has to be achieved and this will need to be altered at different times during incubation Care should be taken to set the ventilation control according to the manufact urer s instructions These may advise particular settings for different room temperatures For example in a cool room below 16 C a minimum level of ventilation should be sufficient with room temperatures above 16 C more ventilation should normally be provided On some incubators a flap covering ventilation holes may need to be moved in others the number of holes that are left open may need to be altered Frequent checks should be made to ensure that nothing is preventing adequate ventila
53. ed at different times or full daily diaries compiled the changes in behaviour that occur with age can be highlighted Comparisons are best made between one and nine day old chicks Table 4 shows some of the easily recognised behaviour pattems that are displayed and how they differ with age It is essential that any investigations of the chicks behaviour do not cause harm or undue stress Pupils can be asked to view a group of chicks quietly for some time and make a list of the number of times each type of behaviour is seen As suggested earlier pecking and feeding behaviour are easily studied Different types of sound made by the chicks should be distinguishable If a new source of food is placed in the brooder chicks will often produce pleasurable twittering noises as they feed and drink Chicks will regularly make distress calls particularly if they become a little cold or become separated from other animals Distress calls are thought to be elicited in unfavourable circumstances to attract the attention of the mother hen The presence of other chicks will affect the frequency of distress calls and this can easily be investigated Alarm calls are often produced when a chick is pecked by another or when the chicks are disturbed by sudden movements Behaviour patterns of chicks Age of chicks Behaviour pattern 1 day 9 day Walking Z Pecking at the ground v r Drinking v r W
54. een considered and meas ured the mass of the chicks will not match their food and water intake For older pupils this observation could lead on to a study of the use of food in keeping the animals warm by generating heat One reason why commercial hatcheries brood their chicks at high temperatures is to reduce feed costs as less food is then used up in maintaining body temperature Another reason why the chicks in school need to be kept warm is the ease with which heat is lost to the surroundings This is particularly a problem for the small chicks which have a large surface area relative to their size As they grow the surface area to vol ume ratio drops and so there is less heat loss This is one reason why the temperature in the brooder can be reduced each week It will not be possible or humane to investigate heat loss directly with the chicks Models of chicks using bottles flasks or tin cans of different sizes can however be used These can be filled with hot water from a kettle and the speed with which their temperatures drop as measured by a thermometer are recorded and related to the size of the container Depending on the age and interests of the pupils this work can be developed into an extensive scientific activity 10 9 Working with feathers Children will be quick to point out that the cans or bottles used to make models are not very representative of the actual chicks which are covered with insul ating feath
55. eloping membranes in the egg RELATING EGG STRUCTURE TO THE CONDITIONS OF INCUBATION USE OF LEARNING MATERIALS AND VISITS TO EXTEND OBSERVATIONAL STUDIES INVESTIGATING THE STRENGTH OF AN EGG SHELL CARBON DIOXIDE SHELL MEMBRANE OXYGEN ALLANTOIS The allantois also serves as a storage area for nitrogen containing wastes particularly a substance called uric acid This is quite poisonous and needs to be removed from the body but it can be excreted as a solid Complete elimination of the uric acid is obviously difficult for the chick enclosed in its shell but the problem is solved by the allantois the solid uric acid stored there is isolated from the embryo where it can do little harm When the chick hatches a pellet of solid material can often be seen inside the shell which is the uric acid deposited within the remains of the allantois As mentioned earlier in section 6 1 the remains of the allantois can sometimes be seen still attached to the newly hatched chick In studying the structure of the egg and considering the function of its various parts the reasons for the precise control of conditions in the incubator should become obvious As the chick embryo is so small it is in danger of losing heat quickly and so retarding or stopping its growth It naturally needs to be kept at the normal body temperature of a hen to ensure that the various body functions can be carried out normally The raised humidity is esse
56. ength during the short days of the winter months Note too that only the female birds that hatch will be required other arrangements will need to be made for the males in the brood see section 8 In addition some form of outside covered run will be needed 50 mm mesh wire netting fixed to a framework will contain the birds and keep out larger animals such as dogs and foxes Chickens are extremely messy animals and so the area in which they will be kept will require very frequent cleaning Chickens have a fairly omnivorous diet Their normal food will be poultry mash supplemented with corn eg from local com merchants see Yellow Pages or John E Haith Although traditionally chickens have been fed on all sorts of household vegetable scraps these should not form the major part of their diet Over feeding with scraps prevents the birds eating the poultry mash which contains the proteins vitamins and minerals they require for egg prod uction They will in addition require a source of grit for grinding the food in their gizzards eg limestone grit and crushed oyster shell grit available from John E Haith The oyster shell grit is a convenient source of calcium in the diet as some of this is soluble An additional source of vitamin D is recommended This can best be provided by mixing the poultry com in a little cod liver oil before feeding the animals 6 5 Rearing birds other than chickens Again it is outside the
57. ent centre near your school animals will be humanely destroyed at no charge though the PDSA normally only offers its services to people with limited finances so arguably a school should not use the PDSA 37 DISINFECTING THE INCUBATOR DISPOSAL OF REMAINS THE IMPORTANCE OF GOOD HYGIENE SALMONELLA DANGER OF BIRDS DEVELOPING RICKETS SUSPECTED ILLNESS MUST BE NOTIFIED HEALTH and SAFETY Disease is unlikely to be a problem if suitable precautions and procedures are adopted It is important to disinfect the incubator before and after the incubation period For details of suitable disinfectants see the information in the footnote on page 22 All other items which come into contact with the animals after they hatch should be disinfected and cleaned before and after use As the chicks and adults are particularly messy birds it is important to clean up after them very regularly again disinfecting the area adequately as necessary All the remains of the eggshells after hatching any unhatched eggs and soiled paper and litter from the brooder should be disposed of hygienically by wrap ping in newspaper and placing this inside a plastic sack before disposal in the normal refuse It is essential that whoever is involved in looking after the incubator and brooder or handling the eggs and later the chicks is aware of the need for good hygiene and is able to wash hands thoroughly and dry them hygienically with paper t
58. ers The containers can then be coated with feathers a feather duster or pillow can be sacrificed in the name of science or alternative insulators used to determine the effects on heat los It will be important to examine the structure of feathers in this work to see how they perform their insulating task so well As the chicks develop their adult plumage the differences between the initial down feathers and their larger replacements can be studied and related to their different functions If appro priate this work can be developed into investigations on flight or the use of feathers for display and courtship in a variety of birds 10 10 Studies of chick behaviour Because incubator reared chicks never see their parents their behaviour patt erns at least initially must be instinctive though later there is the opportunity of learning from other birds Chicks must obviously be capable of fending for themselves immediately after hatching unlike other newly emerged birds which are quite dependent on their parents for food for some time 44 ENCOURAGING CAREFUL OBSERVATIONS LISTENING TO THE SOUNDS THAT CHICKS PRODUCE Table 4 A comparative study of the behaviour of chicks with those of other species will reveal many differences In any behavioural study the important factor is careful observation and rec ording Chicks provide excellent material for encouraging such basic scientific skills If eggs have been incubat
59. es iii The egg white or albumen which has a cushioning effect protecting the embryo against mechanical shocks when the egg is moved In addition it is a source of water which can stop the chick embryo dehydrating and acts to conserve heat so that the embryo is protected from the cold for the short period when the mother moves off the eggs iv The yolk the food supply for the embryo which begins as a small disc on the top of the yolk As the embryo develops blood vessels grow out from the chick over the surface of the yolk to absorb the nutrients more efficiently These vessels can sometimes be seen when candling the developing egg during the irst week of incubation v The chalaza plural chalazae two strands of egg white which support the yolk in the middle of the egg The weight of the egg yolk will keep the embryo at the top of the egg and so nearest to the warmth of the mother bird s body even when it is turned The chalazae serve a vital role in suspending the yolk but allowing it to turn vi The air space which is always at the broad end of the egg This acts as a supply of air which the chick breaks into when about to hatch and begins to breathe using its lungs The oxygen supply in the air space helps in the stren uous efforts of the chick to chip its first hole through the shell If it is thought appropriate a fertile egg can be examined in the same way and the disc of the developing embryo seen
60. es of eggs and equipment a review of incubators and how to set them up a guide to the care and handling of the eggs and the rearing of hatched birds and also gives details of sources of information and some learning materials In short the guide provides all the necessary information to enable successful safe and humane studies of the development of young birds Most of this information concentrates on work with the eggs of the domestic fowl or chicken Gallus domesticus as these are likely to be the most readily available All further reference in this booklet to eggs or young birds will apply to this species unless other animals are named Studies of ducks or other domesticated birds are also possible however and much of the guidance given here will be equally appropriate for these birds too though we recom mend that experience should be gained first with the eggs of chickens There are however some who argue that incubating and hatching eggs should not be attempted in schools because it will be impossible to guarantee that no animal could ever suffer any harm or that animals have rights and that they should not be used to satisfy human interests including education Such a hands off approach to work with eggs and chicks which can be extended to the study of any animals in school will however deny pupils the opportunity of gaining at first hand a true appreciation of the requirements and behaviour of living anima
61. giving good thermal insulation and finished with a durable impervious skin which is easily cleaned Eggs sit on a movable perforated metal platform in the base and are warmed by the heating element in the top section The mercury thermometer is attached to the electronic thermostat and its position can be adjusted so that it is level with the eggs Temperature readings can be easily taken looking through the observation window Humidity is provided by adding water to troughs in the base unit Ventilation holes pierce the base and cover Recessed requiring a screwdriver to adjust within a depression in the top cover Indicator lamp displays when the heater is operating 42 hens eggs Yes A movable platform is powered by a small motor and pushes the perforated metal base tray unit back and forth beneath two metal end units Metal bars are used to separate the eggs so these turn as the base plate moves If very small eggs such as quail are incubated special troughs are required available from the manufacturer Viewed through a double glazed acrylic window in cover 18 5 x 18 5 cm 5 5 kg 53 x 44 x 23 cm high Hatched chicks have a maximum headroom of 14 cm and less than this if standing on eggs Brinsea Products Ascott PY44 Special offer 194 00 inc VAT Banbury Cross 189 00 inc VAT Brinsea Products CPOLA 289 95 inc VAT Domestic Fowl Trust N4 289 95 inc VAT Gamekeepa Feeds HIOSIG4 290 00 inc VAT Hatch it 189 00
62. he essential weight loss of the egg Turning at regular intervals to prevent the egg membranes from stick ing to the inside of the shell and to ensure the eggs warm evenly Egg turning also increases the oxygen intake of the embryo and so encourages development In natural situations all these requirements would of course be provided by the broody hen In an artificial environment they must be provided by the inc ubator under the operator s control Maintaining the conditions around the eggs is a 24 hour job any error could result in death of the developing birds There are various designs of egg incubators available commercially small normally still air models are the most suitable for school use Home made incubators may not provide adequate regulation of all the critical conditions and may therefore reduce the success rate of hatching Commercial hatcheries usually hatch around 80 of hen s eggs In schools the success rate may be somewhat lower than this Some of the egg suppliers such as P and T Poultry also provide advice online Turing the eggs needs to be carried out at least twice a day including at weekends Because of this an automatic egg turning facility for the incubator is a very high priority This can be switched off during the day if pupils are to tum eggs manually For school use an incubator should be durable electric ally safe and also provide a reasonable view of the incubating eggs Not al
63. here is a small loose plastic container for water and this provides humidity There is a fan near the heater and both are protected by a wire mesh cage The therm ometer reads 10 to 50 C and there is a red line at 38 C The thermometer fits in a hole in the lid and the bulb rests on the wire cage inside the lid There is a thermostat temperature adjustment is by a small easily accessible screw on the lid There is a red warning light The lid also has one ventilation hole The screw on the lid is turned by hand clockwise to increase and anti clockwise to decrease You do not need a screwdriver The heater light flashes when the temper ature is stabilising 12 hens eggs No Viewed through translucent dome but obscured by the cage surrounding the heater and fan as well as the translucent plastic 14kg 37 x 25 x 20 cm Hatched chicks have a maximum head height of 10 cm at the sides of the base The standing height is reduced if the chicks are standing on eggs Maino Enrico Adriano Italy Banbury Cross 54 95 inc VAT Rob Harvey 57 99 inc VAT delivery Hatch it Incubators 59 95 inc VAT P and T Poultry 59 99 ine VAT Wheatcroft 0021 55 00 inc VAT A small incubator that is easy to clean and store It comes with an instruction sheet which is translated from the Italian into quaint English To turn the eggs and replenish the water you have to take off the lid and so the humidity and the temperature will f
64. hers should consider the best way of involving pupils in this important activity There are particular problems at weekends as the chicks must nof be left unatt ended for such a long period Arrangements must therefore be made for the chicks to be inspected and their food and water supply topped up It is sensible to increase the number of food and water containers in the brooder over the weekend but this should not be a substitute for personal attention When food and water have become contaminated the chicks are less inclined to use the fouled containers After about four weeks the chicks will begin to develop their adult plumage They will continue to need some additional warmth until their adult feathers are fully developed when it will be possible to keep them outside if desired 6 4 Keeping adult chickens Although many schools will not intend rearing adult chickens it must be app reciated that whoever has agreed to receive the animals may not have facilities for keeping young chicks In these circumstances it will be necessary for schools to keep the birds until they are sufficiently mature to be handed on A decision to keep adult chickens after their time in the brooder must not be made without considerable thought rearing the adults is a major undertaking It will be essential to ascertain whether there are any local authority bylaws or restrictions on keeping livestock on the school premises Neighbours may not 34 OUTDOOR
65. ia but much less than is enjoyed by a mammalian embryo Being enclosed in a protective eggshell creates problems for the chick as well as solving some for the mother The embryo needs an adequate source of food to complete its growth up to hatching time it must be able to receive adequate oxygen for respiration and to remove wastes such as carbon dioxide and nitrogen containing substances The design of the egg and the way the embryo develops are both related to a solution of these problems and when studying the incubation of the eggs it is valuable to highlight the reasons for the precise regulation of several environmental conditions See section 10 2 While eggs are being incubated there is clearly only a limited amount of obs ervational work that can be undertaken One fascinating activity is to float an ncubating egg in warm water at 40 C for a short time and to look for signs of movement of the developing chick or duck etc inside the egg revealed by a slight kick of the floating egg There is little point in trying this early on in the incubation period but towards the end of development you can find out when the embryo starts to become active It is obviously important not to allow an egg to cool down significantly as a result of these observations and the egg should be dried carefully before returning it to the incubator 39 MONITORING DEVELOPMENT BY MEASURING WATER LOSS INVESTIGATING WHAT S INSIDE AN
66. ich one feature at a time is changed For example make models out of cotton wool dyed yellow or left white Make models with and without feet with and without heads eyes beaks etc Does the size of the model affect how chicks approach it vi Is the approach response entirely visual Place two chicks about 50 cm apart with a larger sheet of card in between them so that they cannot see each other but can hear any calls made How do they behave Then move the card away and see what happens Figure 14 Investigating chicks preferences These are just some examples of possible detailed observational studies In evitably further ideas will be suggested by pupils as a result of watching the chicks in the brooder and these can be explored as appropriate 46 OURCES OF INFORMATION and LEARNING MATERIALS For addresses of suppliers refer to section 12 Items marked are more useful for work with younger children 1 BOOKS in print FROM A amp C BLACK distributed by Macmillan FROM BRINSEA PRODUCTS FROM CHRYSALIS CHILDREN S BOOKS FROM DOMESTIC FOWL TRUST FROM DORLING KINDERSLEY FROM TTS FROM FRANKLIN WATTS FROM WHITTET BOOKS Stopwatch series Chicken and Egg Hdbk 0713624256 495 Pbk 071363619X 450 A magnificent photographic guide to chick development Home Poultry Keeping G Eley 0713663197 7 99 A useful reference for those wishing to keep the chickens after hatching and brooding
67. ich variety of duck can be supplied and ask what the incubation period is since this will vary depending on the variety FARMING AND COUNTRYSIDE EDUCATION FACE COLLEGES OF AGRICULTURE CHECK THE SMALL ADS COLUMNS OF SPECIALIST PUBLICATIONS TRANSPORT AND STORAGE OF EGGS FACE has information on its web site there are farms to visit which may also be able to supply fertile eggs There are also fact sheets and teaching materials in the resources section There is a college of agriculture in most counties in England and Wales or a further education college with an agriculture department These may be able to supply eggs or suggest other local sources your local authority or CLEAPSS should be able to give you the address of the nearest college It is also a good idea to ask your local teachers or science centre for suggested local sources of fertile eggs Advertisements for suppliers of fertile eggs are sometimes found in the pages of Cage amp Aviary Birds the Homes amp Gardens section of Exchange amp Mart and also the monthly publication Smallholder These advertisements are also a good way of tracking down suppliers of eggs of other birds such as ducks turkeys geese etc Contact a local newsagent and order a single copy if not readily available If eggs have to be delivered rather than collected arrangements are best made using Amtrak Fertile eggs which are kept cool between 10 15 C will n
68. iers will accept orders on official school order forms Please see note about delivery costs in section 4 2 20 ME 3A Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A rectangular moving air incubator moulded from polyurethane it has a coloured opaque base with an aluminium grid inside and a removable transparent lid which i kept in place by two plastic clips The eggs are warmed by the heating element in the lid Eggs are put into rocking rows in a frame in the base This has a projecting 2 pronged arm into which slots the short rod on the slowly rotating disc which is the turning device Fitting these together is easy Luke warm water is put into the base up to the level of the aluminium grid and then covered with the plastic sheets provided There is a fan near the heater and both are protected by a wire mesh cage The therm ometer reads 25 to 45 C and there is a red line at 38 C The thermometer fits in a hole in the lid and the bulb rests on the wire cage inside the lid There is a thermostat temperature adjustment is by a small easily accessible screw on the lid There is a red warning light The lid also has one ventilation hole The screw on the lid is turned by hand clockwise to increase and anti clockwise to decrease You do not need a screwdriver Heater light flashes when the temperatu
69. igh Hatched chicks have a maximum headroom of 9 cm and less than this if standing on eggs Brinsea Products Semi automatic inc VAT Automatic ine VAT Ascott PY30 8338 PY30 Auto 143 95 Banbury Cross 69 71 120 86 Brinsea Products AOLOIA 92 65 AOLA 159 95 Domestic Fowl Trust IN2A 92 65 IN2B 159 95 GamekeepaFeeds HIO8110 92 70 HIO8C20 164 70 Griffin YSM 200 010Y 10493 YSM 200 030C 186 59 Philip Harris A64531 191 53 Hatch it 69 95 132 00 Insect Lore 288 100 89 96 cradle 288 200 160 77 Interhatch E513100 78 75 P and T Poultry 72 99 124 99 Solway 1133 155 95 Wheatcroft 0002 79 95 cradle 0006 138 28 A very small incubator which can provide automatic egg turning at a cost However the capacity is very small and the space available for the chicks that hatch is restrict ive the larger Octagon 20 DX is better in this respect The Octagon 10 could be used along with a Hatchmaker employed as a hatching unit All plastic construction easy to clean out All the suppliers will accept orders on official school order forms Please sce note about delivery costs in section 4 2 12 Octagon 20 DX Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments All the suppliers will accept orders on official school order forms Please see note about delivery cos This is a compact f
70. ing hens eggs midweek eggs first placed in the incubator on a Monday should hatch on a Sunday and the event may be missed Don t forget that you may need to keep the chicks that hatch for up to 6 weeks so make sure you don t run into a holiday period Allowing a week for setting up the incubator and introducing pupils to the project and a minimum of one week after hatching to allow the chicks to become estab shed at least 5 weeks unbroken schooling is required Depending on when someone can take the chicks from you and how much work you hope the hatched chicks will stimulate a longer period may be needed For the eggs of other birds such as ducks you will need to adjust your timings as their incubation periods are different Remember too that from some sources eggs can only be supplied when they become available other sources may be able to supply on a specific date if sufficient notice is given See sections 5 2 6 and 10 for detailed information This will depend partly on the size of the incubator that you already have pur chased or intend to borrow From some sources there may be a minimum number of eggs that can be ordered will this be too many Incubate too few eggs and you may have a disappointingly low success rate eggs from some sources cannot be guaranteed to be fertile Incubate a larger number of eggs and if you re successful you may have too many adults to find homes for For most situations a minimum of
71. iping the beak v Shaking the head v v Preening the wings Nota lot 7 Raising both wings x r Extending leg and wing on one side A little Scratching the ground x Twittering pleasurably Y Distress call a Alarm call Resting standing up Resting sitting down x The timing of many of the pieces of behaviour can also be studied Do they occur randomly or is there any pattern Are any related to feeding and drinking times to disturbance or to sleeping and resting times 45 INVESTIGATING THE CHICKS BEHAVIOUR OF MOVING TOWARDS EACH OTHER One aspect of chick behaviour in particular can be used for detailed studies the approach of one chick to another If two chicks are placed about 30 cm apart after a short pause one chick will approach the other i Repeat this several times Is it always the same chick that approaches the other On repetition does the time taken before one chick approaches the other decrease If one chick is separated by between 40 50 cm from a pair of chicks which animals move ie which is the most attractive stimulus for moving iii Will a chick approach a reflection of itself in a mirror iv Does a chick prefer to approach another chick rather than an inanimate object of the same size and colour The choice arrangement to be used is shown in Figure 14 v What feature s of a chick are important in initiating an approach move ment Try making models of chicks in wh
72. k PO Box 106 Kidlington Oxford OXS 1JY Tel 01865 842552 Fax 01865 842551 E mail enquiries oer co uk Web site www oer co uk Cleeton Cottage Farm Cleeton Lane Cleeton St Mary DY14 OQU Tel 01584 890263 Fax E mail info pandtpoultry co uk Web site www pandtpoultry co uk 27 Kirchen Road London W13 OUD Tel 020 8567 9206 Fax 020 8566 5120 E mail info peet co uk Web site www pcet co uk Main Street Dundrennan Kirkudbright DG6 4QS Tel 01557 500253 Fax 01557 500652 E mail mail solwayfeeders com Web site www solwayfeeders com 51 FRANKLIN WATTS WHEATCROFT AND SON WHITTET BOOKS Nunn Brook Road Huthwaite Sutton in Ashfield NG17 2HU Tel 0800 318 686 Fax 0800 137525 E mail sales tts group co uk Web site www tts group co uk Watts Publishing Group 338 Euston Road London NW 3BH Tel 020 7873 6000 Fax 020 7873 6024 E mail From web site Web site www wattspublishing co uk Cotswold Rise Hoo Lane Chipping Camden GL55 6AZ Tel 01386 841060 07780 707613 Fax 01386 840742 E mail alastair wheatcroftpoultry co uk Web site www wheatcroftpoultry co uk Hill Farm Stonham Road Cotton Ipswich IP14 4RQ Tel 01449 781877 Fax 01449 781898 E mail contact whittetbooks com Web site www whittetbooks com 52
73. l incubators are therefore suitable and a number of models cannot be recom mended see section 4 2 which evaluates commercial egg incubators 4 1 Borrowing or hiring an incubator Borrowing or hiring an incubator is possible though demand may outstrip supply so plan early See Figure 1 You will need to borrow hire an inc ubator for a period of at least 4 weeks Sometimes the cost of hiring an incubator is greater than the purchase of equipment so check prices carefully A good place to start looking is a local teachers or science centre some may have a loan collection of incubators or may be able to suggest suitable sources Try contacting neighbouring schools both primary and secondary In the past incubating eggs was a feature of several introductory secondary science courses A school science department might therefore have an incubator which is no longer used Rural and city farms may have incubators for loan often as part of a package including fertile eggs and agricultural colleges are also often valuable con tacts see section 3 for details Suppliers who sell incubators may also offer them for hire For example Hatch it Incubators see section 12 is introducing two hire kits based on the Brinsea Octagon 10 and 20 incubators see section 4 2 6 LOANED INCUBATORS MAY NOT MATCH YOUR REQUIREMENTS SOME TIPS WHEN BORROWING OR HIRING AN INCUBATOR BASIC TYPES OF EGG INCUBATOR ESSENTIAL DES
74. ls It will also not help schools in their efforts to promote a general respect for life and in particular caring and responsible attitudes to wards animals kept as pets at home or encountered outdoors Dealing with any form of life of course demands considerable care and fert ilised eggs are no exception If teachers decide that they do wish to incubate eggs they must be fully informed and prepared for every eventuality to en sure the humane treatment of animals This guide aims to help schools and teachers meet this requirement ONLY STUDY DOMESTICATED BIRDS SUCH AS CHICKENS OR DUCKS It is important to realise that studies of the development of any wild British bird which involve taking eggs chicks or adults from their natural environ ment are illegal and must not be contemplated This does not apply to import ed foreign species but there are restrictions on the types of foreign birds that are appropriate for schools and in most cases these animals would not be suit able anyway for detailed studies of development BEFORE YOU START DO I NEED TO OBTAIN APPROVAL WHAT WILL HAPPEN TO THE BIRDS THAT HATCH HOW LONG WILL I NEED TO ALLOW FOR THE PROJECT HOW MANY EGGS SHOULD BE INCUBATED Before attempting to incubate and hatch eggs it is essential that schools con sider what is required to hatch chicks successfully and what will happen to the adult birds once they have emerged Listed below are the major c
75. lso high intensity versions these have a tungsten halogen bulb that CANDLERS continued operates at low voltage and is likely to be more robust with a longer life a transformer is built into the plug None of the egg lume lamps has however been evaluated by CLEAPSS for electrical safety THE EARLY EMBRYO SHOWS At early stages the embryo will be seen as a dark spot perhaps also showing UP AS A DARK SPOT CANDLING REVEALS THE SIZE OF THE AIR SPACE Figure 4 Changes the blood vessels radiating outwards A completely clear egg is infertile As the egg develops the air space at the broad end becomes larger as moisture evaporates from the egg As the embryo becomes larger little light will pass through the egg except to show the air space Figure 4 shows the expected size of the air space of hens eggs and also turkeys amp ducks for comparison at the start of incubation 1 and on specified days if humidity levels have been correct Candling of hens eggs is therefore recommended on the 7th and 14th days of incubation size of air space during days of incubation 14 19 T 24 SS 15 oo E URKEYS amp DUCKS 26 AIR SPACE SIZE SHOWS IF CORRECT CONDITIONS OF INCUBATION HAVE BEEN ACHIEVED IDENTIFYING INCUBATION TEMPERATURES AND PERIODS INCUBATOR CAPACITIES FOR EGGS OF VARIOUS BIRDS TIPS FOR SUCCESSFUL INCUBATION WITH VARIOUS SPECIES If it becomes apparent that the air space is too
76. luctuate Eggs may hit each other if the incubator is lifted or moved carelessly The translucent lid is to be replaced with a transparent one but the importer could not give a date for the change when asked in 2005 All the suppliers will accept orders on official school order forms Please see note about delivery costs in section 4 2 19 MPS 24 Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A small box like moving air incubator moulded from polyurethane it has a coloured opaque or transparent base which is fitted with a wire mesh lining There is a removable transparent domed lid which is kept in place by one retention screw on each side of the base The eggs are heated by the heating element in the lid There is a fan near the heater and both are protected by a wire mesh cage Eggs are put into a metal frame with six horizontal rows this frame has a vertical arm which fits into a rod that projects from a slowly rotating disc near the heater Fixing the two together is easy This rod and frame arm comprise the automatic turning device There is a trough fixed to one side of the base for water The thermometer reads 25 45 C and there is a red line at 38 C The thermometer fits in a hole in the lid there is a rubber band around the thermometer and this should be positioned so that it prevents the therm ometer
77. n this if standing on eggs Brinsea Products Semi automatic inc VAT Automatic inc VAT Ascott PY3I 143 95 PY31 Auto 149 99 Banbury Cross 116 21 145 00 Brinsea Products A024IZA 159 95 AO0DSIZA 219 95 Domestic Fowl Trust INIA 15995 INIB 219 95 Gamekeepa Feeds HIO8I20 160 00 cradle HIOSC20 232 00 Griffin YSM 205 030S 269 43 Philip Harris H71442 251 45 Hatch it 120 00 139 95 Interhatch E513200 135 96 P and T Poultry 149 95 Solway 1139 149 95 1129 207 95 Wheatcroft 0005 132 04 cradle 0006 150 00 A similar design to the Octagon 10 but the larger construction permits a greater capacity and more room for the hatched birds All plastic construction so it is easy to clean out The heating unit can also be fitted on top of a purpose made plastic enclos ure Brinsea 82 70 inc VAT to serve as a brooder A separate unit is also available to monitor and control humidity levels in the Octagon 20 DX but this is a very expensive item costing more than the incubator and we would not recommend its use for most purposes in schools Hatch it Incubators also sells a similar model with a mercury thermometer at 119 99 in section 4 2 13 Polyhatch Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A still air incubator moulded from polyurethane
78. nd very much on its type or size and this is far from ideal anyway Acquiring a key for access to the building for the duration of the project would cause the least inconvenience to the premises manager but this is not always possible The premises manager can also help to ensure that the incubator is not accidentally turned off by cleaners ete A label stating Please leave on near the plug socket will help too Ensure that all the required equipment is available incubator brooder or mat rials to construct one chick food etc see sections 4 6 2 and 6 3 Much of this can sometimes be borrowed or hired see section 4 1 but demand for these items invariably exceeds the amount of equipment available for loan so it is vital to plan many months ahead Make sure that borrowed equipment is available for the time required including at least one week prior to starting ncubation so that the temperature control can be tested Make sure that the school is prepared to meet the financial costs of any items that need to be bought eg the eggs and possibly their delivery charge the brooder lamp and the chicks food young chicks eat a tremendous amount In advance try to locate someone in the area who has had first hand experi ence of incubating eggs as he she may prove helpful in the event of some emergency or problem Teachers centres and advisers may be able to suggest contacts You must accept responsibility for the welfar
79. ntial to prevent too much moisture being lost through the porous egg shell Adequate ventilation is vital to provide oxygen and also to remove carbon dioxide which will kill the embryo if it accumulates What is often missing in any study of reproduction in the chicken or duck is an appreciation of the events leading up to the egg being laid as well as changes occurring within the egg By the appropriate use of books and audio visual materials however aspects of reproduction involving courtship copulation fertilisation and development within the egg can readily be illustrated and discussed A visit to a local rural or city farm that keeps chickens can also be valuable Details of some learning materials are given in section 11 10 3 Science from eggs Some interesting side line activities might arise from the study of eggs to discover their structure Children often consider eggs to be rather fragile obj ects they are after all easily broken Pupils are therefore very surprised to discover that eggs can withstand considerable pressures before breaking esp ecially if the force is exerted with an egg standing on one end using a small cup cut from an egg box to support it There is much scope here for exper nenting measuring and recording What influences the strength of an egg s size its colour its freshness Does it matter how a force is applied to the egg for example either gradually loading it with weights on t
80. nufacturer Source Comments Both the 136 and 137 are still air incubators constructed from high quality laminated plywood which has a plastic coating and a frame constructed from mahogany A domed sheet of 4 mm high grade Perspex covers the top of the incubator Heating elements are situated behind ventilated metal grilles on all four sides of the egg chamber Humidity is provided by water added to a compartment beneath the egg tray which can be pulled out for refilling and so avoids opening the incubator A sheet of hessian is used as a wick over the water tray Ventilation is controlled by the movement of a lever which adjusts a flap that exposes or covers holes in the base of the incubator An electronic thermostat is situated on the side of both incubators The temperature sensor is on a flexible arm which passes through the cover and can be adjusted so that its position is at the top of the eggs Model 136 15 20 hens eggs Model 137 Up to 40 hens eggs Model 136 No eggs are placed in the egg tray which has a wire mesh base and should be lined with a sheet of hessian Model 137 Yes a motor moves adjustable rollers which slowly rotate the eggs once each hour For hatching the rollers can be removed and eggs transferred to the egg tray below This has a wire mesh base and should be lined with a sheet of hessian Automatic turning can be switched off to allow movement of the eggs by hand during the day It is possibl
81. onsiderations that you must have addressed before starting a project to incubate some eggs Approval of the headteacher is needed as aspects of the project could well affect normal school life It is also a good idea to involve other teaching staff and then much of the workload can be spread among several people This has obvious advantages and provides a back up team if needed If you are teaching in a Local Authority establishment it is possible that there may be some local restrictions on egg incubation keeping animals or rearing livestock outdoors though these should already have been sent in writing to schools Unless you are planning to keep the adults at school are confident that they can be provided with the long term care required and have checked that there are no restrictions on keeping poultry outdoors it will be necessary to arrange a home for the hatched birds in advance It is inhumane and illegal to consid er releasing unwanted chicks or ducks into the wild You must also be aware that someone may take your chicks but surplus males may then be used for food as they don t lay eggs See sections 6 4 amp 8 for discussion of the options Think carefully about the timing of the incubation project during the school term to ensure that the eggs will hatch when pupils will be present and not during a weekend or half term holiday For the eggs of chickens the incuba tion period is 21 days You need to start incubat
82. op of a board resting on the egg or adding them quickly with a sudden jolt How should the tests be performed so that they are fair How might the way an egg is laid by the hen relate to its strength when squeezed in different ways 42 WHAT MAKES EGGS CRACK WHEN THEY ARE BOILED INVESTIGATING HATCHING INVESTIGATING THE CHICKS EYESIGHT CHARTING GROWTH AGAINST FOOD AND WATER CONSUMPTION Another familiar observation worthy of investigation is the infuriating habit of eggs breaking when being boiled Various cures are often recommended adding salt or vinegar to the water or adding the eggs to cold water and then boiling them Do they work If so why and why do the eggs break anyway The clue to understanding what is happening involves the porous nature of the egg shell and the air space It is thought that on rapid heating the volume of the air inside the space expands quickly so cracking the shell and allowing the contents to escape If water is gradually warmed from cold the slowly expanding air has time to escape through the pores of the shell Puncturing the broad end of an egg with a pin will provide a vent for the expandii should also solve the problem Adding salt and vinegar increasing the acidity affects the nature of the proteins in albumen causing them to denature and coagulate These cures might therefore work by sealing any cracks that develop preventing further leakage Again there is much scope f
83. or observation and investigation 10 4 The chicks hatch Once the embryo has completed its development there is obvious excitement among the pupils and plenty of opportunity to encourage close and careful observation accurate measurements of various factors plus suitable methods of recording and display all essential components of science activity Do all chicks begin to hatch at the same time Interestingly chicks placed in the incubator at different times can all hatch together under certain circum stances Once the first hole appears in the egg how long does it take for the chick to emerge fully from the shell Is this time the same for all the chicks Is there any relationship between the mass of the egg and the mass of the bird once its feathers have dried Is this perhaps linked to its strength in escaping from the egg A chick can easily be weighed in a container on top of a set of sensitive scales or perhaps placed inside a plastic bag and suspended from a spring balance 10 5 Observing chicks When the chicks have dried and recovered from their hatching ordeal they can be handled and moved to the brooder Now pupils can observe them closely noting their important features and behaviour Of particular interest at this time is the egg tooth on the beak which was used to help the chick break out of the egg This soon disappears now that its task is over Do the chicks have ears Where are they and how are they diffe
84. orced air incubator made out of plastic moulded into an octagonal shape A base unit contains two troughs for water to provide humidity above which is an egg tray with movable spacers A see through double glazed top unit gently warms the eggs with heat emitted from 10 black element strips printed onto the plastic A quiet fan housed on the underside of the top unit circulates air and a slider is used to control air input through ventilation holes Eggs are turned manually by just rotating the entire unit rather than opening it up and moving eggs individually There is a built in digital thermometer An easily accessible control plus electronic thermostat and indicator lamp display which are fitted in the top unit Fine adjustments are made with a small screwdriver 24 hens eggs Yes if a special cradle is used The cradle rocks the eggs from side to side through a 45 angle in each direction A motor in one end of the cradle slowly turns an arm which moves the incubator continuously through two turns per hour Viewed directly through the plastic sides of the top cover However the heating strips plus the top unit housing the fan somewhat obscure the view and as chicks hatch a build up of moisture causing condensation may further reduce visibility 1 9 kg incubator 1 0 kg cradle 33 x 24 x 24 cm high With cradle 41 x 24 x 28 mm high Hatched chicks have a maximum headroom of 17 cm but restricted to 12 cm in some places and less tha
85. order delivery charges These vary greatly Ascott delivery to mainland England Wales and lowland Scotland is included n prices Banbury Cross delivery is included on some models at cost on others Brinsea delivery is 4 50 on orders below 75 and 7 00 on orders above 75 Dog Health delivery is 7 50 The Domestic Fowl Trust delivery is 8 30 Gamekeepa delivery is 11 00 Griffin Education has no delivery charge to schools in the UK other than those on offshore islands for orders over 50 below this there is a 10 handling charge Philip Harris charges 6 95 on all orders Rob Harvey prices include delivery Hatch it Incubators has prices which include delivery on all but Maino models Interhateh has no delivery charge Insectlore charges 3 95 on orders up to 250 above that delivery is free P and T Poultry has a delivery charge that depends on weight it is 7 95 for orders weighing up to 30 kg Solway Feeders delivery charge depends on the weight of the order Wheatcroft delivery charge is 12 50 A comparison of egg incubators Information about the incubators we feel are potentially of most interest provided in Table 1 and on the following pages to help schools decide if a particular model is suitable for their needs Cost may be the most crucial dec iding factor but schools should appreciate the limitations that may be imposed by going for the least expensive option Information on Cu
86. ot begin their development and it is claimed that they can be stored or transported for a period of up to 7 days without significant losses It is best however to begin incubation as soon as possible after the eggs are laid or transport despite clair s from various sources that the broad end of an egg should be p ing upwards or downwards licated that the orientation of the egg has little effect on subsequent hatching or survival 5 INCUBATORS BASIC REQUIREMENTS FOR NORMAL DEVELOPMENT AND HATCHING USING COMMERCIAL INCUBATORS TO SIMULATE NATURAL CONDITIONS IMPORTANT FEATURES OF AN EGG INCUBATOR FOR SCHOOL USE TRACKING DOWN INCUBATORS FOR LOAN To develop and hatch eggs require the following factors to be controlled Warmth to encourage the embryos to develop at the natural rate the eggs of different species requiring a different optimum temperature Humidity to control the normal weight loss of the egg that must occur during incubation for successful hatching and to prevent egg shell mem branes becoming too dry for hatching Different humidity levels need to be provided at certain stages of incubation with a very high humidity at the time of hatching Ventilation to ensure a good supply of oxygen and most importantly to remove the carbon dioxide produced so that it does not poison the devel oping chicks An appropriate air flow also encourages evaporation of water for t
87. ot meet one or more of the important criteria discussed above A more appropriate strategy is to choose the incubator that meets your needs and then see if your budget can stretch a little if necessary In the pages which follow we have not included the more expensive incubators though some suggested models are still quite costly We do not recommend a number of models of incubator some of which are on the market These include ones made from expanded polystyrene and ones which are electrically unsafe The Ecostat Economy range as supplied by Ascott is made from expanded polystyrene and such incubators are unlikely to be durable in typical school use The models include PY63 80 egg capacity manual turn PY242 45 egg capacity semi automatic PY243 45 egg capacity automatic and those known as Ecohatch PY64 60 egg PY244 30 egg push rod semi automatic and PY245 30 egg automatic Furthermore an earlier version of the Eco hatch incubator did not pass our electrical tests The Hovabator range as supplied by Solway feeders model 1360 60 egg capacity manual turning still air incubator failed our electrical tests This supplier also sells the Solway 24 a 24 egg semi automatic incubator which also failed electrical tests The Marsh Turn X7A was featured in the 1997 guide It is manufactured in the USA and is difficult to obtain Therefore we have not included it in thi revision Table on page 10 summari
88. owels or their equivalent both before and after coming into contact with the animals and equipment Such precautions are standard practice when working with any animal or plant material but are particularly important in work with chicks because of the possibility that the eggs and the hatched birds might be carrying Salmonella bacteria which can cause food poisoning The risk of infection can however easily be reduced to insignificance if simple hygiene is practised It may be wise to discourage the handling of chicks by any child who is known to be allergic to animals Similarly any cuts in the skin on the hands should be suitably protected before chicks are handled Young and adult chickens can easily develop rickets if an adequate supply of vitamin D and calcium is not included in their diet This should not be a prob lem if good quality feed plus grit such as crushed oyster shells are used It is most unlikely that the hatched chickens will show any signs of infectious disease but if some ailment is suspected it is essential that the animal is taken to a vet This is because certain conditions such as Newcastle s disease must by law be notified to the authorities In these circumstances it is not sufficient just to destroy the animals humanely 38 COMPARING CHICK DEVELOPMENT WITH THAT OF OTHER ANIMALS THE ADVANTAGES amp DISADVANTAGES OF DEVELOPING INSIDE AN EGG CHECKING THE INCUBATED EGG FOR SIGNS OF LIF
89. r consumed will not be unimportant either 43 WHAT FOODS ARE PREFERRED USING TIN CAN MODELS OF CHICKS TO STUDY HEAT LOSS FEATHERS FOR INSULATION FLIGHT AND DISPLAY INSTINCTIVE AND LEARNED BEHAVIOUR Pupils should be encouraged to think how water consumption could be meas ured accurately Calibrating the water level in the drinking fountain can be attempted but a lot of water will simply evaporate from the dish The need for recording water loss from an identical control fountain kept at the same temp erature as that in the brooder may be suggested An additional factor will be the amount of droppings produced This could be measured by weighing fresh sheets of paper lining the floor of the brooder at the beginning and end of each day 10 7 Investigating feeding Work on pecking at objects will readily extend into a study of feeding It is unwise to allow children to experiment too extensively on the foods that the chicks will eat as in this way the birds can easily be given a quite unsuitable diet As the birds mature and can take larger pieces of food it is interesting to investigate which foods are preferred and whether this is related to the size colour etc of individual items such as com and grain Findings here can then be extended to include studies of wild bird populations particularly pigeons outside the school 10 8 Investigating heat loss Even if all the aspects affecting gain in mass have b
90. r to buy you should consider the following CJ How will the incubator stand up to the rigours of use in schools Is construction likely to be durable CJ Is the incubator electrically safe At the School Science Service we have inspected some of the models currently on sale and for those we have looked at and passed we can be confident about their safe construction Models we have not inspected may nevertheless be electrically accept able In the discussion of individual models summarised in Table 1 and described on subsequent pages we are satisfied with their electrical safety To ensure that a thermometer will be sufficiently sensitive and accurate over the range 35 45 C it is important to use one which has been made for use with an incubator All the incubator manufacturers and suppliers als list various types of thermometer sp fically produced for such work Wet and dry bulb thermometers are often recommended as these also measure humidity However such readings are very inaccurate and we do not feel that wet and dry bulb thermometers are particularly useful 7 ESSENTIAL DESIRABLE FEATURES OF AN EGG INCUBATOR continued INCUBATORS TO AVOID INCUBATORS SUITABLE FOR MOST SCHOOL USES CJ How easy is it to see the incubating eggs Since a major reason for starting an incubation project is to enable pupils to watch the eggs hatching an unobstructed view will normally be a high priority Does th
91. r you have available it is vital to refer to the manufacturer s instructions supplied with it These have been written to give the best results with that particular model and some aspects may not be app licable when using other incubators For this reason it is not easy to provide detailed guidance here which will be appropriate for work with all types of incubator These notes therefore should be regarded as general guidance only The illustration below represents the popular Curfew 137 incubator although other models have a different construction they share many of the basic features Figure 2 Features of an egg incubator THERMOMETER BULB AND VENTILATION HOLE IN LIO THERMOMETER HELD INLD THERMOSTAT SENSOR SET AT THE SAME HEIGHT AS THE TOP OF THE EGGS VO WITH TERSPO wool INCUBATING EGG AUTOMATICALLY TURNED ON ROLLER tangen CONTROL BOX St ROLLER ATTACHED TO RACK WITH FLEXBLE SENSOR ARM ROULNG Leste INTERNAL FRAME COVERING HEATER MOTOR GG TRAY UNED HATCHING EGG REMOVED FROM WITH HESSIAN ROLLERS AND PLACED IN TRAY VENTILATION onan VENTLATON WATER TRAY WITH HOLE HESSIAN WCK SITING THE Place the incubator on a level surface in a position which is not prone to vast INCUBATOR fluctuations in temperature and humidity ie out of draughts direct sunlight and away from central heating radiators Be warned that in winter schools often become very cold at night once the heating is off If the temperature
92. re is stabilising 50 hens eggs Yes Good Viewed through the transparent lid best at the sides 5 65 kg 57 x 40 x 29 cm The head height of hatched chicks is variable depending on where the chicks are in the incubator It varies between 8 and 12 cm The standing height reduced if the chicks are standing on eggs in the turning frame Maino Enrico Adriano Italy Banbury Cross 135 00 inc VAT Rob Harvey 149 99 inc VAT delivery Hatch it Incubators 139 95 inc VAT P and T Poultry 149 99 inc VAT Wheatcroft 0022 135 00 inc VAT A larger incubator than the MPS 24 but it is just as easy to clean and store It comes with an instruction sheet which is translated from the Italian into quaint English To replenish the water you have to take off the lid and so the humidity and the temperature will fluctuate The importer says that this model can also be used as a brooder once all the eggs are hatched because the temperature can be reduced to one appropriate for that purpose The plastic sheets that are placed over the aluminium frame to help regulate humidity may easily be lost as they could be mistaken for packing material However the importer claims the regulatory process is not affected if they are missing All the suppliers will accept orders on official school order forms Please sce note about delivery costs in section 4 2 21 INCUBATING EGGS 5 1 Setting up an incubator Whichever model of incubato
93. rent from those in other animals Look at the eyes Where are they placed on the head and how does this compare with other birds particularly predators such as owls How is this and the field of vision the eyes provide related to the behaviour and lifestyle of birds Chicks often will peck only at bright objects and ignore food scattered on the floor of the brooder There is lots of scope here to investigate what the chicks can see with various objects of different sizes and colours presented to them on different coloured surfaces and their pecking at these objects recorded 10 6 Recording growth amp development Pupils will enjoy keeping a daily diary of the chicks development Information can be recorded here of the day to day changes that occur in behaviour and appearance of the chicks Quantitative studies of growth can easily be undertaken by weighing daily the food that is given and comparing this with the mass of the birds when they are weighed food conversion efficiency is rarely greater than about 10 Tables and graphs of data can be compiled showing rates of development The need for taking average readings from all the birds will become evident because of individual variation particularly if gain in mass is related to food given Pupils might wish to consider the discrepancies between mass of food presented and the readings obtained when the chick is weighed Wastage of food in the brooder will be a factor but wate
94. required change has to be found by trial and error The light bulb flashes when the temperature is stabilising and this could be distracting in the classroom The all plastic construction is easy to clean Advice about this and other aspects of operating the incubator are contained in the detailed instruction book There is a red version of this incubator which is available from P and T Poultry it is cheaper 39 99 inc VAT but has a fixed thermometer and is not fully insulated A converter plug is required All the suppliers will accept orders on official school order forms Please see note about delivery costs in section 4 2 15 Covatutto 16 Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A larger version of the Covatutto 7 it is a still air incubator moulded from poly urethane giving good thermal insulation The incubator has an opaque yellow circular base and transparent plastic removable dome Heat is provided by a 40 W golf ball light bulb heater fixed in a black plastic holder in the centre of the dome Humi provided by adding water to two troughs in the base unit Small ventilation holes are pierced into the clear dome The mercury thermometer is inside a plastic case and this slots into a hole in the dome Eggs are placed on a moulded platform inside the base The bulb of the thermometer i
95. required thermostat setting For some birds such as ducks and quail there are several different varieties or species for which eggs may become available and so again different temper atures and incubation times may be quoted It is therefore important to ask the supplier of the eggs for the recommended incubation temperature and suggested incubation period and any other tips on successful hatching Also check with the incubator manufacturer if details of the necessary conditions are not given in the accompanying instructions Nevertheless an attempt is made below to offer some general advice for differ ent birds and a summary of recommendations is given in Table 3 overleaf Most manufacturers indicate the capacity of their incubators in terms of num bers of chicken eggs To find the approximate number of eggs of other birds that can be accommodated refer to Table 3 and multiply the stated capacity by the conversion factor Several authorities suggest that duck and probably goose eggs require a slightly lower incubation temperature than the eggs of chickens while the eggs of guinea fowl pheasants and quail should have a slightly higher incub ation temperature For turkeys some suggest that the temperature should be increased by about 0 5 C each week starting at 38 C and ending up at 39 4 C for the last week Some sources state that the eggs of ducks geese and turkeys should receive regular spraying or even soaking
96. rfew models is included even though we have doubts about supply consequently we have not included details of prices and they do not feature in Table 1 Prices quoted mostly include VAT Remember to check the delivery charge A number of suppliers provide kits containing all the equipment needed for incubation and brooding These often represent remarkable value for money when compared with the total cost of purchasing items separately Different suppliers have the same kits but sometimes give them different names Some kits are produced specifically for the home market eg Ascott kits others such as those from Griffin and Harris have lesson guidance and are more suited to schools Table 2 overleaf gives details of some of these kits There are several available including the Ecostat Incubator kits available from the Domestic Fowl Trust and Ascott and the Interhatch Kit available from Interhatch These may seem good value but will take time to construct and you will often have to find important supplementary parts for yourself for tance the Ecostat Incubator kit for 25 eggs comprises only the electrical components thermometer and instructions there is no incubator box Table 1 Egg incubators most suitable for use in school Model Manufacturer Source Lowest Capacity Automatic Portability Observation price inc hens tuming of eggs VAT eggs Hatchmaker Brinsea P
97. roducts A BC BP DF HI IH P TS W_ 110 00 36 No Small and light Poor Octagon 10 Brinsea Products A BC BP DF GF GE HI IH IL 89 71 10 Yes with Very ight but Partially PH PT S W 120 86 cradle needs care restricted Octagon Brinsea Products A BC BP DF GF GE HI IH PH 116 21 24 Yes with Light but needs Somewhat 200X PT S W 139 95 cradle care restricted Polyhatch Brinsea Products A BC BP DF GF HI IH PT S W 17999 42 Yes Large but OK Quite poor Covatito Novital A DF DH IH PT 40 38 6 7 No Small and light Somewhat 7 restricted Covatuto Novital A DF DH IH PT 5057 1216 No Small and light Somewhat 16 restricted Covatutio Novital A DH IH PT 10837 20 24 No Heavy but Good A possible MPSI2 Maino BC HI PT RH W 54 95 12 No Small and light Poor MPS24 Maino BC Hl PT RH W 90 00 24 Yes Good size and Good from easy to cany _ the side ME3A Maino BC Hl PT RH W 13500 50 Yes Good sizeand Good from easy to cany _ the side 1 The sources listed are shown by the following codes details of addresses etc are in section 12 A Ascott BC Banbury Cross BP Brinsea Products DF The Domestic Fowl Trust DH Dog Health GF Gamekeepa Foods GE Griffin Education HI Hatch it Incubators IL Insect Lore IH Interhatch PH Philip Harris PT P amp T Poultry RH Rob Harvey S Solwa
98. s above the position of the eggs Recessed requiring a screwdriver to adjust within a depression in the black lamp holder on top of the clear dome The heater bulb flashes when the temperature is stabilising 12 16 hens eggs No Viewed through clear plastic dome 17kg w partially obscured by lamp holder Diameter 30 cm height 30 cm Hatched chicks have a maximum head height of 12 cm at the centre of the base The standing height is reduced if the chicks are standing on eges Novital Ascott PY297 59 99 inc VAT Dog Health C16 69 99 inc VAT delivery Domestic Fowl Trust INI 69 99 inc VAT Interhatch ES17500 50 57 inc VAT delivery P and T Poultry 54 99 inc VAT The mercury thermometer is held in position in the clear rigid plastic cylindrical case by two springs which fall out if the case is opened quickly The case has a section which acts as a magnifying glass and this must be positioned over the reading scale of the thermometer This has a thick red line indicating 100 F and there are two finer red lines one above and one below this There is no indication either on the therm ometer or in the instructions as to the significance of these lines The temperature is adjusted by turning the recessed screw clockwise to increase and anti clockwise to decrease but the extent of the turn needed to produce the required change has to be found by trial and error The light bulb flashes when
99. scope of this guide to give much advice here There have been many publications produced over the years describing what is involved in rearing species such as ducks geese turkeys quail pheasants etc Suitable references may be obtained from local libraries see also section 11 Of the alternatives to chickens the duck is perhaps the most likely bird to be chosen for studies in schools Ducks are certainly delightful animals and their slow hatching is a definite bonus However we would not recommend that teachers attempt to rear ducklings until they have been successful with chickens Ducks are extremely messy animals they splash water everywhere and leave very liquid droppings The litter on the floor of the brooder soon becomes very wet unless complicated arrangements are established with a raised pond and ramp Providing food is more of a problem in that supplies have to be wet and feeding is a messy business the animals need to be able to clean their beaks which quickly become coated with food Water is consumed very rapidly and so water fountains need to be checked and topped up very often Weekends are a partic ular problem in ensuring continual supplies of food and water 35 HANDLE CHICKS BY CUPPING IN THE HANDS SEXING MOST CHICKS IS EXTREMELY DIFFICULT HANDLING and SEXING The chicks when first hatched are extremely weak and delicate and unless in obvious distress should not be handled for the first few hours
100. ses the models of incubator currently available that are potentially most suitable for schools to use The incubators listed have been examined by the CLEAPSS School Science Service and all should be electrically safe A new Brinsea model the R Com Digital arrived too late to be included here it is perhaps too small for schools with only a 3 egg capacity If schools wish to incubate eggs on a larger scale than can be accommodated in the incubators listed in the table all the manufacturers supply models which will hold a greater number of eggs Prices naturally are considerably higher than for the models described here contact the manufact urer or sole source for details 8 DON T FORGET SPARES and ACCESSORIES DELIVERY CHARGES COMPLETE KITS D LY KITS One strange feature is that the cost of Brinsea incubators may be cheaper from some suppliers than the manufacturer This is because of bulk order deals negotiated by the supplier Also some suppliers have special offers from time to time so it is worth contacting them directly to establish the current costs Prices are those quoted by suppliers in November December 2005 but could already have changed When ordering your incubator it is wise to purchase an additional incubator thermometer in case of breakage You may also need other items for candling eggs brooding and feeding chicks etc and you may wish to order some of these from the same source This may help avoid small
101. the temperature is stabilising and this could be distracting in the classroom The all plastic construction is easy to clean Advice about this and other aspects of operating the incubator are contained in the detailed instruction book There are two models one with a red base and the other with a yellow base The yellow base is fully insulated and the prices above are for this model All the suppliers will accept orders on official school order forms Please sce note about delivery costs in section 4 2 16 Covatutto 24 Description Temperature control Capacity Automatic egg turning Egg chick observatio Mass Dimensions Manufacturer Sources Comments A box like incubator moulded from polyurethane and having good insulation There is a brightly coloured base and a clear plastic removable cover There is a fan assisted 75 W element heater in the centre of the cover a variable temperature control and a fitted mercury thermometer in a plastic case with a magnifying section There is a removable plastic platform on which the eggs are placed and plastic removable egg separators which can be adjusted to take any size of egg Humidity is controlled by placing water in the basin at the bottom of the incubator Recessed requiring a screwdriver to adjust within a depression in the black heating element housing on top of the clear lid A green warning light flashes when the temperature is stabilising 20 24
102. ties yourself Wi Check any borrowed equipment carefully it may not have been used for a long time or been given regular routine checks Therefore thoroughly test all borrowed incubators for safety inspecting the state of the wiring and plug Arrange for a portable appliance test unless you have evidence that this has been done recently Clean all parts according to the manufact urer s instructions see section 5 1 Wi Avoid home made incubators unless you know they have a good track record in hatching eggs successfully E Allow plenty of time to check the correct functioning of the thermostat Also the incubator may have lost its own thermometer and you may need to obtain one from another source Wi insist on obtaining a copy of the manufacturer s instructions with the inc ubator Without these it will be very difficult to ensure successful hatch ing as only the manufacturer will know exactly how best the incubator should be operated to produce the necessary conditions 4 2 Purchasing an incubator As might be expected commercial egg incubators are available to suit most pockets and the requirements of amateur and professional users There are two main types of incubators the still air variety which relies on convection for ventilation and forced air models which may be larger and more expensive Many models of incubator that are suitable for schools are of the still air type Before deciding which incubato
103. tion Refer to section 5 2 for more information on regulating ventil ation 5 2 Incubating chicken eggs First allow the fertile eggs to warm up to room temperature for at least 12 hours before placing them into the incubator Cool eggs may lower the temperature of the incubator or be stressed if they are warmed up too quickly In the old but popular Curfew incubators as shown in Figure 2 whenever eggs are to be placed into an egg tray it is important to line the tray first with a piece of loose weave material such as hessian or a dishcloth Hessian should be provided with new incubators spares may be available from Curfew Incub ators or other suppliers Since the tray has a metal mesh this can become hot so it is essential that all the eggs are on the cloth inside the tray and also are not touching the vertical sides of the tray if these are also made of metal The material must nof be moistened with water Ifall goes to plan the chicks should hatch after 21 days so do not set the eggs on a Monday or they will hatch out at the weekend Do not start to incubate the eggs before a holiday period or there may be difficulties in caring for the adults or observing the chicks for the desired period Turing helps to prevent the developing membranes from sticking to the inside of the shell If it is not possible for the eggs to be turned regularly cluding at weekends schools must accept that embryos will often be dam aged an
104. to hatch There can be a period of several hours between the first hole being made in the shell and final emergence Only intervene if it appears that a chick has become stuck for a period of 24 hours or more Then it may be helpful to enlarge very carefully the hole with forceps or scissors Keep the points of the instruments parallel to the shell and nof inserted inwards or the chick may be damaged Hatching can take a long time in other species duck and turkey eggs for example can take between 36 hours and 3 days If these species are being kept it is important not to become impatient and help the birds along This longer hatching time can be useful as it ensures that all children will have an oppor tunity to observe the hatching process something that can be missed with the eggs of chickens when it occurs during the night When the chick emerges it will be wet often blood stained and very weak It will need at least 12 hours to dry out and it will be some time before it can stand without falling over It should be left in the incubator or hatcher for this period and then removed to a brooder as described in section 6 2 There may be insufficient oxygen in an incubator for many chicks to breathe and an incubator is an unsuitable enclosure in which to feed and water the young animals 29 PROBLEMS OF AN EXPOSED YOLK SAC STORAGE OF WASTES IN THE ALLANTOIS REMAINS OF THIS MAY BE SEEN AT HATCHING DO NOT DISPOSE OF UNHATCHE
105. ubator Egg lume cand Philip Harris Duro 1337 00 exc VAT and Classroom Pack ling lamp Wet dry bulb thermometer delivery brooder module chick enclosure 1 itre drinker CD ROM and Lesson plans 2 Hatch lt Incubators also sells kits based on the Maino MPS 12 and 24 models costing 79 95 and 139 95 3 Ascott produces several other kits at greater cost there is a deluxe version which includes a brooder cage and costs 237 95 The 7 and 16 egg kits could be used with the Interhatch School Brooder kit which contains plastic surround brooder drinker feeder wood shavings and chick food 10 Hatchmaker Description Temperature control Capacity Automatic egg turning Egg chick observation Mass Dimensions Manufacturer Sources Comments A still air incubator moulded from polyurethane giving good thermal insulation and finished with a durable impervious skin which is easily cleaned Eggs sit on a perforated metal platform in the base and are warmed by the heating element in the top section The mercury thermometer is attached to the electronic thermostat and its position can be adjusted so that it is level with the eggs Temperature readings can be easily taken looking through the observation window Humidity is provided by adding water to troughs in the base unit Ventilation holes pierce the base and cover Manufactured to BS 3456 and EN 60 335 Recessed requiring a screwdriver
106. urycrossincubators com BANTA LTD Unit 9 Burnt Oak Business Park Back lane Waldron TN21 ONL Tel 01435 810200 Fax 01435 810210 E mail sales bantabiology com Web site www bantabiology com A amp CBLACK 37 Soho Square London WID 3QZ Distributors Macmillan Tel 020 7758 0200 Fax 020 7758 0222 E mail customerservices acblack com Web site www acblack com BRINSEA PRODUCTS LTD Station Road Sandford BS19 SRA Tel 0845 226 0120 Fax 01934 820250 E mail sales brinsea co uk Web site www brinsea co uk BRITISH EGG 1 Chelsea Manor Gardens London SW3 SPN INFORMATION SERVICE Tel 020 7808 9790 Fax 020 7351 5092 E mail info britegg co uk Web sites www britegg co uk www eggsedu org uk CHRYSALIS CHILDREN S The Chrysalis Building Bramley Road London W10 6SP BOOKS Tel 020 7314 1400 Fax 020 7314 1594 E mail childrens chrysalisbooks co uk Web site www chrysalisbooks co uk CURFEW INCUBATORS Paul Chewter Unit 1 Butterfly Lodge Mersea Road Abberton Colchester COS 7LG Tel 07963 969681 Fax 01206 736121 E mail paulchewter netscape net DOG HEALTH NUTRITION Unit 3 Tower Meadows Castle Acre Road Swaffham PE37 7LT Tel 01760 726340 Fax 01760 721006 E mail doghealth ukonline co uk Web site www doghealth co uk DOMESTIC FOWL TRUST _Honeybourne Pastures Honeybourne Evesham WR11 7QZ Tel 01386 833083 Fax 01386 833364 E mail dft domesticfowltrust co uk Web site www domesticfowltrust co uk DORLING KINDERSLEY
107. y Feeders W Wheatcroft Table 2 Complete kits Manufacturer s Contents of kit Suppliers Manufacturer Ordercode Gost inc VAT and delivery kit name or assembler unless stated Beginners Box Octagon 10 incubator Brinseat NTOZR 159 95 delivery 7 00 Egg lume candiing lamp Domestic Fowl Trust IN28A 159 95 delivery 4 00 Infra red brooding lamp Hatch it Incubators None 119 00 special offer Feeding trough 10 the ante Wheatcroft 5000 135 00 exc delivery Chicken and Polyhatch automatic incubator Brinseat NIA 359 95 delivery 7 00 Egg Box Egg lume candiing lamp Domestic Fowl Trust IN26 359 95 delivery 4 00 MA Hatch Incubators None 269 00 Pierins P and T Poutty None 289 99 Information booklet Wheateroft 5002 310 00 exc delivery Complete Home Covatutto 24 semi automatic incubator Ascot PY285 159 99 Hatchery Kit Egg ume canding lamp P and T Poutty None 194 99 Humidity meter Brooder Feeder Drinker Instruction book T Egg Kit Covatuto 7 incubator interhatch EUTEKTM 5413 exc VAT Canding lamp Incubator book 63 60 inc VAT 16 Egg Ki Covatuto 16 incubator nterhatch EIGEKTM 6281 exc VAT Canding lamp Incubator book 73 80 inc VAT incubator Octagon 20 incubator Egg lume cand Griffin Education YSM 200 333H 300 00 exc VAT Classroom Pack ling lamp Wet dry bulb thermometer CD ROM and Lesson plans Odagon20 Octagon 20 inc

L71 Incubating and Hatching Eggs

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