In recent years, the time of traditional spring climate characteristics has become shorter and shorter, and the transition period between winter and spring and spring and summer is also prone to bad weather such as "cold spring", and the spring environmental conditions with frequent alternating hot and cold stress on laying hens It is an important reason for the frequent occurrence of serious diseases such as bird flu and respiratory tract, and it has also become the most difficult to control biosafety risk for laying hens. In view of these problems, the healthy breeding of laying hens in spring should pay special attention to the following aspects:

1. Pay attention to the harm of spring temperature change stress to different chicken ages
The frequently changing climate in spring will cause varying degrees of harm to laying hens throughout the production period, but special attention should be paid to the "four age groups".
1. Brooding period: Spring is the golden season for brooding, but frequent changes in external temperature will cause damage to the health of chicks, and the consequences of this harm will affect the life of laying hens. Generally, the younger the chicken age, the more serious the consequences.
2. Early stage of breeding (50-60 days old): This stage is mostly the period when laying hens are transferred to groups. Environmental stress can lead to the induction of Mycoplasma synoviae in chickens, affecting the health and laying performance of laying hens throughout their lives.
3. Over-primary laying period: If the fragile constitution of laying hens encounters strong environmental stress during this period, it will not only seriously affect the increase of egg production rate, but also cause irreparable damage to the production performance of the entire laying period.
4. Peak egg production period: The high production period is a period when the immune function of chickens is weak. Any environmental temperature stress will affect the egg production performance, and it is difficult to make up for it later.

2. Pay attention to the contradiction between insulation and ventilation of the chicken house, and make reasonable ventilation
Pay attention to the contradiction between insulation and ventilation in the chicken house, and maintain the appropriate temperature in the house. The most difficult thing in raising chickens in spring is how to properly ventilate the closed chicken house. The core is how to increase or decrease the ventilation volume of the chicken house in a timely manner according to the change of the external temperature, so as to maintain the appropriate temperature in the house. It is mainly carried out by adjusting the opening number of the fan and the opening size of the air inlet.
Adjust the ventilation volume to reduce the temperature difference in the house.
Adjust the ventilation mode to respond to environmental changes.
Adjust the ventilation window to control the ventilation speed.

3. Pay attention to spring-prone diseases and strengthen spring prevention and immunity
1. Avian influenza H5 and H7 avian influenza are the biggest killers in winter and spring. They are easy to recombine and mutate, and vaccine strains will become ineffective after two or three years of use. To strengthen monitoring, the use of vaccines with effective strains. The laying hens are immunized 3 times before laying, and once after the peak of egg production. In the future, they will be immunized on a regular basis according to the antibody test situation.
2. Infectious bronchitis. The 5-day-old chickens and the laying hens were immunized with the local epidemic strains once each; the combination of live vaccines and fire-fighting vaccines can greatly increase the antibody titer.
3. Mycoplasma gallis synovialis is mainly transmitted vertically, but it is also easy to spread horizontally. The common peak incidence of laying hens has three stages: 20-40 days of age, mostly due to vertical transmission of infection; 60-70-day-old brooding house transferred to breeding chicken cages with strong stress infection; 90-110 days old primiparous period stress infection. The disease can be prevented and controlled by vaccine, immunization once at 20 days and 10 weeks of age. But the focus is on comprehensive feeding management and prevention and control.
4. Infectious rhinitis. This disease is easy to recur in chicken farms. It is recommended to be immunized at 5 weeks and 15 weeks. When using the vaccine, add bidirectional cephalosporins mixed injection to prevent mixed infection. The trivalent vaccine can be used for immunization, and the single-bacterial immunization based on popular strains can also be used in some places.
5. Newcastle disease. Spring laying hens were sprayed with new vaccines every 1 month, and after the peak of egg production (32 weeks), they were boosted with inactivated vaccines. It is best to use a vaccine of the genotype VII isotype, which can greatly improve the protection rate.

4. Pay attention to refined health management
1. Strict environmental disinfection to reduce the load of environmental bacteria.
2. Refined management, timely preventive administration. During this period, preventive administration can be taken according to the condition of the flock, especially before and after the occurrence of various stresses (such as group transfer, immunization, and sudden changes in weather), multidimensional and antibiotic supplementation should be given in time. In particular, after artificial insemination of chickens, preventive administration of fallopian tubes should be carried out in a timely manner according to the status of their fallopian tubes and egg production to prevent the occurrence of salpingitis.
3. Special attention should be paid to the H5N8 avian influenza epidemic. Free-range poultry is not isolated, and wild birds and poultry are fed together, and the risk of cross-infection is high. Therefore, it is necessary to strictly control the pollution of wild birds in chicken farms.