Factors affecting hatching

During the development of chicken embryos, the gas exchange must be carried out, especially after the 19th day of incubation (12 hours earlier in summer), the embryos begin to breathe, the oxygen demand gradually increases, and the carbon dioxide emissions gradually increase. At this time, if the ventilation is not good, it will cause severe hypoxia in the incubator. Even if the breathing rate of the chicks out of the shell is increased by 2-3 times, the need for oxygen cannot be met.

As a result, the intermediate process of cell metabolism is inhibited and acidic substances are prevented. Accumulated in the body, the partial pressure of carbon dioxide in the tissues increases and metabolic respiratory acidosis occurs, which leads to a decrease in cardiac output, and myocardial hypoxia, necrosis, cardiac disturbance, and beating arrest

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It is determined that the oxygen consumption of each embryo egg throughout the incubation period is 4-4.5L, and the carbon dioxide emission is 3-3.5L. Tests have proved that if the oxygen content in the incubator drops by 1%, the hatching rate drops by 5%; the carbon dioxide content around the embryo egg should not exceed 0.5%. When the carbon dioxide reaches 1%, the embryonic development will be delayed, the mortality rate will increase, and the deformity will increase.

Generally, the normal amount of oxygen in the air can be maintained at 20%-21%. Therefore, the key to ventilation is to try to reduce the concentration of carbon dioxide around the embryo eggs, and the effect of ventilation is related to the structure of the incubator equipment, the architectural design of the incubator (room), and the internal and external environment of the incubator.

Comparing the factors that affect the hatching rate, the temperature is the first, followed by ventilation. Why are many books sorted by temperature, humidity, ventilation… instead of temperature, ventilation, humidity? The reason is simple. The method of artificial incubation is imitated by the mother poultry. Choose a dry place for holding eggs for female poultry. Birds are mostly on trees.

There are not many hatchings at a time, so you don’t need to worry about too much ventilation. Artificial incubation is different. Modern incubators can hold tens of thousands of eggs. More than that, so ventilation becomes important. Moreover, many experiments in previous years have proved that waterless incubation does not affect or does not affect the hatchability.

Most old-fashioned incubators have disadvantages such as a small number of fans, low speed, and unreasonable distribution. Not only are there insufficient ventilation and dead spots, but also the heat source heat cannot be sent to all places as quickly and evenly, which makes the temperature difference in the incubator too large. For this reason, the incubator should be modified or replaced with a new one.