The success of any hatching of eggs depends on the quality and fertility of the eggs being incubated and the care and management of the incubator. The critical factors to consider in management are temperature, humidity, ventilation and rotating of eggs. Failing to meet the requirements of any one of these invariably results in disastrous consequences. Farmers often ignore or forget some of these requirements and as a result suffer losses and become frustrated with the incubator or the business as whole.
Ensure good egg quality
If you are going to produce the eggs in your farm it is important to consider the hens that will lay the eggs and the cocks that will fertilize them. Select parents with proven fertility and good lineage. Purchasing eggs is tricky but get a reliable source in terms of fertility. Before placing them into the incubator, you need to inspect the eggs for normal shape, good size and smooth unbroken shells.
If the eggs are not going to be placed in the incubator immediately, they should be stored in a cool and humid area (preferably at 12 - 15°C and 70-75% humidity) with the large end facing upwards, and turning them daily. You can store the eggs up to 10 days but it has been observed that eggs that are set in the incubator less than 7 to 10 days after they are laid have the best hatching. Allow cool eggs to warm up to the ambient temperature before putting them into the incubator.
Do not wash eggs unless it is necessary, and in that case always use a damp cloth with water warmer than the egg. This causes the egg to sweat the dirt out of the pores. Never use water cooler than the egg. Also, do not soak the eggs in water.
Using simple candling instruments regularly test the quality of eggs by candling. All the eggs of the same age should look the same. Infertile eggs and dead embryos can be detected and the eggs removed before they can produce unwanted gas. Candling is best started on the 9th day and a second one done after 14 to 18 days of incubation. After the 18th day no candling of eggs should be done so as not to disturb the growing chicks.
Using the incubator and other procedures
Setting up of the incubator
Place the incubator in a room with good insulation, little fluctuations in temperatures and good ventilation. If you are using the incubator for the first time, operate it for at least one week without eggs. Set up a thermometer on the egg tray with its bulb at a level with the top half of the eggs. If you have several thermometers check to see that the heat spreads evenly across the tray. Open up 2 to 4 air holes and wait for the temperature to stabilize, making adjustments before the incubator settles at the right temperature.
If you are using a lamp, turn the lamp wick up or down to adjust the heat until you have a constant temperature of 38.9°C. Fill up the lamp regularly with kerosene to ensure constant supply of heat. When the temperature in the incubator has remained stable for at least 24 hours without having had to adjust the thermostat regulation can be said to be complete
Completely fill the water tank with hot water at about 40o C. The heat will spread better if there is no air in the tank. Put a container of hot water in the incubator and check the humidity level. When everything is set up properly the eggs can be put on the tray.
Temperature during incubation
The optimal temperature in the first two weeks is 38.9°C. Any rise above 40.5°C is fatal for the embryos. Also a drop in humidity can have disastrous results. From the 19th day onward reduce temperature to 36.1oC because the chicks will be producing their own heat. If new-born chicks with open beaks can be made out, they are trying to lose heat by breathing more. This might indicate too high a temperature in the incubator.
Humidity levels are influenced by the amount of ventilation and humidity levels of the incoming air. You can measure humidity by use of a hygrometer but they are too expensive. A wet bulb thermometer is a cheaper alternative. Adjust the humidity by putting containers of warm water inside the incubator. Use water at body temperature rather than cold water to prevent the temperature from dropping. Put wet sponges or clothes in the incubator if you don’t have enough containers. Or use a thoroughly cleaned sprayer filled with warm water and spray into the incubator through the ventilation holes.
Growing chicks may suffocate or choke if there is insufficient ventilation. Open the ventilation holes regularly. Every time you open the door to turn the eggs fresh air will enter. When you stop turning the eggs after 19 days you may need to open extra holes. At least two holes will have to be permanently open in any case.
Turning the eggs
Hatching results will be very poor if you do not turn the eggs. Turn the eggs 3 times a day at regular intervals for the first 19 days and do not move them. Turning is no longer necessary thereafter.
To accurately do this mark one end of each egg, say with an X, and the other with an O. Turn them all so that in one day all have the Xs facing upwards and on the next, the Os. This is very important to ensure that there is even temperature on all surfaces of the egg.
Leave the door of the incubator closed as much as possible to prevent the incubator from cooling down. The best way is to take the entire egg tray out, turn the eggs 180° and put in the egg tray the other way around. Exchange the eggs at the centre with the eggs on the edges of the tray if the heat is not reaching all the eggs equally. Keep your hands clean.
Do not help the chicks from the shell at hatching time. Prematurely helping the chick hatch could cripple or infect the chick. Humidity is critical at hatching time.
As soon as the chicks are dry and fluffy or 6 to 12 hours after hatching, remove the chicks from the incubator. Remove all the chicks at once and destroy any late hatching eggs.
During Power Outage
In case of power failure ensure that eggs are as warm as possible until the power returns. Do this by placing insulation materials like blankets over the top of small incubators. Then place lit candles under the box that covers the incubator to warm the eggs. The heat from the candles can easily keep the eggs above 32°C until the power returns. Embryos have survived at temperatures below 32°C for up to 18 hours. Candle the eggs 4 to 6 days after the outage to check whether they are still viable and if not, terminate incubation. A power outage usually delay hatching by a few days and decrease the hatchability to 40-50 percent.
Sanitation of Incubator and Equipment
Lack of sanitation decreases hatchability. Always thoroughly clean and disinfect the incubator, all hatching trays, water pans and the floor of the hatchery before and after use, no matter what type of incubation you use. The incubation room and egg storage area should equally be kept clean.
Write down the date on which the eggs were put into the incubator. Note the temperature and humidity twice a day. If hatching results are poor at the end of the incubation period, your records will tell you whether the temperature or the humidity levels were to blame.
Normally hatching rates vary from 50 to 70%. It is rare to achieve 80% or over.