What are the prevention and control measures for infectious bursal disease in chickens?
(1) Strengthen feeding management and hygiene measures Strengthen the feeding management of the chicken flock, maintain intervals between chick placements, implement an all-in-all-out rearing system, carry out thorough cleaning, hygiene and disinfection work, and reduce and avoid various stress factors. These general principles for preventing and controlling infectious diseases are extremely important for the prevention and control of infectious bursal disease.
(2) Vaccination Through effective vaccination, the chicken flock acquires specific resistance, which is the most important measure for preventing and controlling infectious bursal disease.
1. Increase the antibody levels of breeder chickens In addition to immunization with intermediate-virulence live vaccines during the chick stage, breeder chickens should also be immunized once each at 18-20 weeks of age and 40-42 weeks of age with an infectious bursal disease oil-emulsion inactivated vaccine in order to increase the maternal antibody levels of their progeny chicks.
2. Immunization of chicks The timing of the first immunization of chicks should be determined according to the maternal antibody levels of the chicks. After hatching, the maternal antibody levels of the chicks should be measured every 3 days by the agar gel diffusion method or the enzyme-labeled method. When the agar gel diffusion positive rate of the flock reaches 30%-50% or the average OD value of the enzyme-labeled method reaches 3000-3500, the chicks should receive their first immunization; the second immunization should be carried out 7-10 days after the first immunization. If testing conditions are not available, the first immunization can be carried out at 12-14 days of age and the second immunization at 20-24 days of age. The vaccine used is an intermediate-virulence vaccine.
(3) Prevention and control of affected flocks
1. Strengthen feeding management: appropriately reduce the protein content in the feed (to about 15%) and increase the vitamin content. Appropriately raise the temperature of the chicken house, add 5% sugar or oral rehydration salts to the drinking water, and reduce various stresses.
2. Carry out strict disinfection of the chicken house and the @#@230@#@ environment. Organic iodine preparations, chlorine-containing preparations or formalin have a strong killing effect on the virus of this disease.
3. In the early stage of the disease, timely injection of infectious bursal disease hyperimmune serum or hyperimmune yolk homogenate has a good prevention and control effect. When there is mixed infection with bacterial diseases, administer symptomatic antibiotics to control secondary infection.