Ventilation and oxygen supply during incubation

Oxygen consumption amount during incubation process. At the first few days of incubation, the metabolic activity is inactive and only very little oxygen is needed. Until the 4^th day of incubation, the metabolic activity increases. Until the 18^th day of incubation, the respiratory capacity of 720 chicken embryos is near that of a human. When it comes to pipping period, the chorioallantoic membrane’s function falls down, and the respiration will be through lung function. At this phase, more oxygen is needed. According to the measurement, the oxygen consumption per embryo is about 0.51mL/hour at the incubation beginning, 17.34mL/hour on the 17^th day, 0.1-0.15L/hour on the 20-21 day. In the whole incubation period, the oxygen consumption accounts for 4-4.5L and the carbon dioxide given off is around 3-5L.

Fresh air contains about 21% oxygen and 0.03-0.04% carbon dioxide. Usually, the oxygen content should be kept above 20% and the carbon dioxide content should not exceed 0.05%. When carbon dioxide exceeds 0.05%, the hatchability will decreases and when exceeding 5%, the embryos will die out.

Mostly, the egg incubator has vents. Even the vents are closed, but not completely, the ventilation is still there due to that the temperature difference between inside and outside causes strong air exchange. This is especially typical for small egg incubators with less than 2000 eggs holding capacity. Even for large egg incubator, as long as it the ventilation system is reasonably designed, installed and operated, and the air in the incubation room is fresh, oxygen deficit seldom occurs in such case. Instead, what should be noted is to avoid excessive ventilation because excessive ventilation may consume too much power and lower the humidity in the incubator, which will adversely affect the embryonic process. But in hot summer, because of little temperature difference between inside and out side of the incubator, the air exchange is not so fierce. In this season, attention should be paid to ventilation to prevent embryos death due to suffocation.

 The incubator vents are usually exposed to the incubation room, so the air condition in the incubation room greatly influences the air quality in the incubator. Without good ventilation and room temperature in the incubation room, it is hard to any superior egg incubator to perform at its best. Therefore, to expect good hatchability, the incubation room must have good thermal insulation functions, as well as stable room temperature and good ventilation mechanisms.

Oxygen supply, especially for high altitude incubation

Usually, there is no need to specially supply oxygen into the incubator, except in high altitude areas. Eggs produced in low altitude areas but incubated in high altitude area should be given special attention. In high altitude areas, comparatively higher permeability may cause excessive evaporation of egg water, and lead to dehydration and low hatchability. In addition, the embryos can come across oxygen deficit, hypocapnia, and other symptoms, in high altitude areas.

In high altitude areas, special instrument must be available for oxygen supply, to assure oxygen content between 20-21%, and carbon dioxide content at 0.03-0.04%. Furthermore, the humidity must be increased by 10%-20%. Try to reduce ventilation as long as the carbon dioxide content doesn't exceed 0.04%, so as to save oxygen and electricity for heating and supplying humidity.