Two periods that can not be ignored in the hatching of chicken eggs
During the whole incubation period, chicken breeding eggs need to be operated and managed by a human certificate. However, according to the characteristics of embryo development, there are two key periods: 1-day embryo age to 7-day embryo age and 18-day embryo age to 21-day embryo age. In the incubation operation, we should try our best to create the incubation conditions suitable for the development of embryos in these two periods, that is, we should grasp the main contradiction between improving the hatching rate and the quality of chicks. Generally, pay attention to heat preservation in the early stage and ventilation in the later stage.
1-day embryo age to 7-day embryo age
In order to improve the incubation temperature and shorten the time to reach the appropriate incubation temperature as soon as possible, the following measures are taken:
1. Preheating the seed eggs before hatching can not only help the chicken embryo wake up and recover its vitality, but also reduce the temperature drop in the incubator and shorten the heating time.
2. After incubation for 1 to 5 days, all the air inlets of the incubator are closed.
3. When using formalin and potassium permanganate to sterilize the eggs in the incubator, it should be carried out after the surface of the egg shell is condensed and dried, and avoid the embryonic eggs of 24 hours to 96 hours.
Do not light the eggs before the embryonic age of 4.5 days to prevent the temperature of the incubator and the egg surface from dropping sharply. The whole batch of eggs should be photographed after 5 days of embryo age. In addition, broken eggs should be eliminated.
5. Increase the ambient temperature of the incubator.
6. Avoid long-term power failure. In case of power failure, in addition to raising the temperature of the incubator, you can also heat water in the water pan.
18-21 day embryo age
The embryonic age of chicken embryo from 18 days to 19 days is the period during which the embryo transits from chorionic respiration to lung respiration. The oxygen demand increases sharply, and the embryo self-temperature is very high. With the pecking and hatching, the pathogenic microorganisms in the shell spread rapidly in the incubator, and the ventilation in this period should be sufficient. To solve the problem of oxygen supply and heat dissipation, the following measures should be taken:
1. Avoid transferring the dish to the hatching dish at the embryonic age of 18 days. The disc can be moved at the embryo age of 17 days in advance or at the embryo age of 19 days in advance.
2. Increase the humidity and reduce the temperature when pecking and hatching. On the one hand, it is to prevent the water evaporation in the egg from accelerating when the egg shell is pecked, which is unfavorable for breaking the shell and hatching; On the other hand, it can prevent chicks from dehydration, especially when hatching lasts for a long time, it is more important to improve the humidity. The hatching temperature of the hatching incubator should be reduced while increasing the humidity to avoid high temperature and humidity at the same time. When the embryo age is from 19 to 21 days, the temperature of the hatching device should not exceed 37 ℃ to 37.5 ℃. The relative humidity increased to about 70%~75% during hatching.
3. Pay attention to ventilation, and increase the ventilation volume if necessary.
4. Ensure the normal power supply. Even if the power is cut off for a short time in this period, the impact on the incubation effect is not small. In case of power failure, the emergency measures are: open the machine door, turn up and down, and measure the egg temperature with a thermometer. At this time, the temperature displayed by the door thermometer must not represent the temperature in the incubator.
5. The selection of picking time is generally the first time when 60%~70% of the chicks come out of the shell and the hair is dry. Before that, only empty eggshells were picked up. After hatching, the eggs without hatching will be moved to the top of the hatching device for hatching. Finally, pick the chicks once and sweep the plate.
6. Shading of observation window. The chicks have phototaxis, and the chicks that have come out of the shell will be crowded to the front of the chick plate. Unfavorable to other embryo eggs. Therefore, the observation window should be shaded to keep the chicks quiet.
7. Prevent chicks from dehydration. Dehydration of chicks seriously affects the survival rate and is irreversible. Therefore, chicks should not stay in the incubator and the chicken processing room for a long time. It is impossible for chicks to come out at the same time. Even if it is neat, the time difference between the earliest and the latest is about 32 hours. In addition to a series of work after hatching, such as grading, injection and identification, the time will be longer. Therefore, it may have been nearly 48 hours from the time of hatching to the time of delivery to the breeder. Therefore, it should be delivered to the nursery or the user in time