Incubator
Introduction
In order to provide eggs and chicken to Factor e Farm Dream Team 30, we will need to raise our chicken population from 24 to about 300 chickens in 2009. For this, we need to hatch the chickens in an incubator, as natural brooding does not do the trick. We are getting 8 eggs per day even now, and this should increase to about 20. At this rate, it would take us one month of hatching to increase our flock to the needed level. We should aim for an incubator with 48 egg capacity, and do about 5 hatching runs.
Design Rationale
Naturally, hens take care of the eggs by turning them often and sitting on them to maintain the necessary conditions for hatching. The hatchability of eggs in this situation can be variable. Some hens can get 100% hatchability but this is not guaranteed.
An incubator keeps a large number of fertilized eggs safe and warm under ideal conditions until they hatch, ideally with a higher than normal hatchability percentage.
The important conditions under the hen are temperature, humidity, ventilation, and turning. The eggs need to be turned for circulation, or else the fluids just sit there.
Care of Hatching Eggs
Before setting eggs in an incubator, you must obtain or produce quality fertile eggs from a well-managed, healthy flock which are fed properly balanced diets.
1. Keep the nest full of clean, dry litter. Collect the eggs early in the morning and frequently during the day to prevent excessive chilling or heating of the eggs.
2. DO NOT wash eggs unless necessary. If it is necessary to wash eggs 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. If the egg is allowed to soak in water for a period of time, the temperature difference can equalize and bacteria has a greater chance of entering through the pores.
Be sure eggs are dry before storing. Never place damp or wet eggs in a styrofoam carton for storage.
3. Store the clean fertile eggs in an area which is kept at 55°- 60°F and 70-75% humidity. Never store eggs at temperatures about 75°F and at humidities lower than 40%. These conditions can decrease hatchability dramatically in a very short period of time.
Slant or turn the fertile eggs daily while they are being stored. Store the eggs small end down and slanted at 30-45 degrees. Putting a piece of 2" x 4" under one end of the carton or storage container and changing it to the other end daily works well.
Do not store eggs for more than 10-14 days. After 14 days of storage, hatchability begins to decline significantly.
4. Just before setting the eggs, allow them to warm to room temperature (70-80°F) and remove any cracked eggs.
Incubation
Four factors are of major importance in incubating eggs artificially: temperature, humidity, ventilation and turning. Of these factors, temperature is the most critical. However, humidity tends to be overlooked and causes many hatching problems. Extensive research has shown that the optimum incubator temperature is 100°F when relative humidity is 60 percent. Concentrations of oxygen should be above 20 percent, carbon dioxide should be below 0.5 percent, and air movement past the egg should be 12 cubic feet per minute.
There are two types of incubators commonly used:
1. Forced-air incubators which have a built in fan to circulate the air. 2. Still-air incubators which have no fans, so the air is allowed to stratify.
The forced-air incubator should be set at 99-99.5°F and 60-65% relative humidity (83-88°F wet bulb). The advantage of the forced-air incubator is that it is easier to maintain humidity at a constant level because of air circulation.
Still air incubators are smaller and air flow is harder to manage. Set still-air incubators at 100 to 101°F at egg height. This is important since the air stratifies in these incubators. There can be as much as a 5° difference in temperature from the top to the bottom of some of the still-air incubators. Humidity should be 60-65% (80-90° wet bulb) during incubation and 70-75% (92-97° wet bulb) at hatching time. It is very easy to overheat the eggs in still-air incubators and difficult to maintain proper humidity.
Temperature
During the warm-up period, the temperature should be adjusted to hold a constant 101°F for still air, 99°- 100°F for forced air. To obtain reliable readings, the bulb of the thermometer should be at the same height as the tops of the eggs and away from the source of heat. Using two thermometers is a good idea to ensure you are getting an accurate reading.
Incubator temperature should be maintained between 99° and 100°F. The acceptable range is 97° to 102°F. Mortality is seen if the temperature drops below 96°F or rises above 103°F for a number of hours. If the temperature stays at either extreme for several days, the eggs may not hatch. Overheating is more critical than underheating. Running the incubator at 105°F for 15 minutes will seriously affect the embryos, while running it at 95° for 3 or 4 hours will only slow the chick's metabolic rate.
An incubator should be operated in a location free from drafts and direct sunlight. An incubator should also be operated for several hours with water placed in a pan to stabilize its internal atmosphere before fertile eggs are set. Do not adjust the heat upward during the first 48 hours after eggs are set. This practice cooks many eggs. The eggs will take time to warm to incubator temperature and many times in small incubators the incubator temperature will drop below 98°F for the first 6-8 hours or until the egg warms to 99°-100°F.
General Info
http://www.associatedcontent.com/article/308949/how_to_hatch_your_own_chicks_from_eggs.html?cat=53
Designs
- http://www.msstate.edu/dept/poultry/avianemb.htm
- http://www.mixph.com/2007/07/constructing-a-plywood-incubator.html?cp=1
- http://msucares.com/poultry/reproductions/poultry_make_incubator.html
- http://www.extension.umn.edu/distribution/livestocksystems/DI0631.html
- http://www.backyardchickens.com/LC-howto.html
- http://www.motherearthnews.com/Do-It-Yourself/1982-03-01/Build-Your-Own-Incubator.aspx
Links
- http://www.bantychicken.com/cgi-bin/bantychickenwiki.pl?Hatching
- http://www.ext.vt.edu/pubs/poultry/factsheets/8.html