Duck egg production, lighting and incubation
Egg production from the egg-laying strains is very high when groups are small. But when ducks are raised commercially, production falls rapidly because of the ducks’ nervous tendencies, and therefore becomes less economic.
Muscovies are the only breed that generally goes broody. They lay their eggs in batches of about 20; the first few eggs of the first batch will be small and they should not be set for incubation.
Ducks usually begin laying at about 6–7 months of age and should be laying at a rate of about 90% (i.e. 100 ducks laying 90 eggs daily) within 5 weeks of the onset of laying. English breeds normally maintain more than 50% production for about 5 months. Pekins start laying eggs when they are about 26–28 weeks of age and can be kept economically for about 40 weeks of production, when they will have laid about 160 eggs.
Egg production and overall performance is best if breeding ducks are housed together in groups no bigger than 250 birds. Nest litter should be changed daily after most eggs have been laid. With morning lighting programs the bulk of eggs are laid between 4.00 am and 7.00 am.
Electric lights can be used to bring ducks more quickly to full production and to shorten the period of moult (when birds have a pause in production). Artificial lighting for 2 weeks or so before eggs are required for setting can achieve this. Supplement natural daylight with artificial light so that birds receive about 15 hours of total light (see Table 1).
Table 1. Fifteen-hour light program for layers on constant daylength
Note: Do not adjust time clock to daylight saving time.
|Morning light||Evening light||Morning and evening light|
|ON am||OFF am||ON pm||OFF pm||ON am||OFF am||ON pm||OFF pm|
There is no production advantage in using fluorescent lights instead of incandescent lights, but the fluorescent tubes or bulbs are more economical to run. Make sure the light shines on all feeders, drinkers and nests. Ducks require a light intensity of about 10 lux and this can be provided by one 60 watt incandescent bulb for every 18 m2 of floor space.
English breeds might panic when the lights go out in an evening lighting program. All-night lighting can prevent such panic, using one 15 watt bulb for every 18 m2 of floor space. If all-night lighting is not practised, morning lighting is preferred to evening lighting. A combined morning and evening lighting program can be used; however, the same problems of possible panic at night must be considered. Blackout training from day one when ducklings are first hatched may prevent later problems of panic when lights are turned off.
Lights should be operated by a time switch that has a reserve spring. Check the lights daily. Remember that daylength decreases in autumn by about 15 minutes each week until the middle of June, when it increases by 15 minutes each week until the middle of December. The aim of the lighting program is to give birds a constant 15 hours of light per day.
Most ducks lay their eggs during the night or early morning. Eggs must be gathered first thing to prevent them becoming dirty and to keep breakages to a minimum. If ducks are laying while you are collecting eggs, allow them to stay on the nest — make another collection 2 hours later. It is preferable to collect eggs directly onto plastic egg filler trays. Keep dirty eggs separate from clean eggs.
Selecting eggs suitable for incubation
Some eggs have little or no chance of hatching. Because of this, and to conserve incubator space, set only those eggs that are likely to produce ducklings. Do not select eggs that are obviously underweight, cracked or heavily mottled, or those that have poor shell texture. Those eggs not suitable for incubating will probably be fit for human consumption.
Dirty eggs must be cleaned immediately after collection to prevent disease and spoilage micro-organisms from penetrating the shell. Lightly rub them with fine-grade steel wool to remove dry mud and manure. The eggs may then be wiped with a clean damp cloth.
Avoid washing them as this removes the waxy covering over the shell and poorer hatchings can occur. If some eggs do need to be washed, use warm water (about 45°C). Cold water should not be used as it will cause the contents of the egg to contract, allowing dirt and bacteria on the shell to contaminate the egg. It is advisable to add a sanitiser to the water. Iodine-based compounds, chlorine solutions and quaternary ammonium compounds are suitable sanitisers. If eggs are not washed, consider fumigating them using formaldehyde gas in a fumigation cabinet immediately after collection.
Eggs will probably need to be stored until there are enough to incubate. Most breeders prefer to have only one hatching day per week. The longer the eggs are kept, the less chance they have of hatching. The chance of hatching decreases greatly after 7 days, and it is most unlikely that ducklings will be hatched from eggs kept for 3 weeks, even under the best storage conditions.
Storage temperatures are critical. Ideally, eggs should be stored at 13°C with a relative humidity of 75%. Low temperatures can cause the embryo to die; high temperatures can start incubation. Store eggs with the pointed end down. If they are to be kept longer than 7 days, turn them daily through an angle of 90° with the pointed end down.
Artificial incubation (agitated air)
To hatch ducklings successfully in an artificial incubator designed to incubate chickens, certain adjustments need to be made, particularly for Muscovies. Some reasonably good results have been obtained with both the laying and English breeds. The incubator room need not be elaborate, but it must be adequately ventilated and able to maintain a constant temperature under all conditions.
Run the incubator for a full day before setting, to test if it is working properly and to build up and maintain the desired temperature. Remove eggs from cool storage to room temperature 6 hours before setting; this prevents a sudden rise in temperature when they are placed in the incubator. Transfer them, with the pointed end down, to incubator trays.
All breeds hatch in 28 days with the exception of the Muscovy, which takes 35 days.
Set the incubator to run at 37.5°C. Maintain this temperature throughout incubation but reduce it by 0.2°C in the hatchers.
Too much humidity prevents eggs from drying out sufficiently; too little causes the contents to dry out too quickly. In either case, eggs fail to hatch.
Humidity can be controlled by adjusting the ventilators of the machine and by the use of moisture trays. High humidity gives best results. Set eggs at a relative humidity of 70% (a wet bulb reading of 33°C and a dry bulb reading of 37.5°C). Humidity may be allowed to fall to 65% but should be increased to 70% when hatching (chipping) begins.
Turning the eggs allows free movement of the embryo and prevents the egg’s contents from sticking to the shell. Eggs should be turned
through an angle of 90° (shown at right). If turning has to be performed manually, this should be done at least three times a day. Automatic turning equipment should be set to turn the eggs every hour.
Eggs are candled by shining an electric light through them so that their contents can be clearly seen, and embryonic development determined. Eggs may be tested for fertility on day 7. A live embryo is seen as a dark spot in the large end of the egg, near the air cell, with blood vessels radiating from it. Infertile eggs are clear, and a dead embryo shows as a dark spot stuck to the shell membrane.
Remove the infertile eggs, and the eggs with dead embryos, from the trays. Eggs may be further candled after 25 days’ incubation (32 days for Muscovies) to remove any dead-in-shell ducklings and to allow more room for hatching. This is the time to transfer the eggs to the hatchers.
To destroy harmful bacteria, particularly Salmonella pullorum, fumigate incubators at least once during incubation. If you fumigate only once, do it on day 25 (on day 32 for Muscovies) of incubation. The cheapest and surest method of fumigating is to mix formalin with potassium permanganate (Condy’s crystals) to produce formaldehyde gas.
To fumigate the incubator, first turn off the incubator motor. Place the required amount of potassium permanganate in an earthenware container on the floor of the incubator, then pour over it the required amount of formalin. (Note: 25 g of potassium permanganate and 35 mL of formalin (40%) are enough to fumigate 1.0 m3 of incubator space.) Close the incubator door, and allow the machine to run for at least 10 minutes at the normal operating temperature and at maximum humidity. To prevent operators being overcome with formaldehyde fumes, open the doors and windows of the incubator room to provide ventilation before actually opening the incubators. When fumigating, it is advisable to wear a respirator mask with a suitable cartridge filter.
Taking off the hatch
As soon as possible after the hatch is completed, transfer ducklings to the brooders. Some causes of poor hatches include incorrect operation of the incubator, faulty management of the breeding flock, poor nutrition, and genetic weaknesses in the breeding stock.
Ducks vary in hatchability much more than chickens. Hatchability can be from 60% to 75%, depending upon the age of the flock and the general management conditions.
It is very difficult to hatch Muscovy eggs artificially. Muscovy ducks can be used to incubate and hatch out their own eggs or the eggs of any other breed of duck, and can easily cover 16 eggs. To incubate Muscovy eggs ‘artificially’, place the eggs under a duck for 10 days and then transfer them to an artificial incubator. Better results are obtained if the eggs are again put under broody ducks for a day or so every week until about day 30, when they can be hatched in an incubator.
Ducks sitting on eggs should exercise daily and be provided with food and water near their nest. Both English breeds and the Muscovies can be satisfactorily hatched out under broody hens.