What are the disease prevention and control methods for large-scale chicken farms?

Scientific management practices and a strict disease prevention system are the foundation for controlling the occurrence of various infectious diseases. In terms of management, an all-in-all-out system should be adopted, with brooding chickens, growing chickens, and laying hens raised in separate zones. Manure should be concentrated in a manure yard far from the chicken houses, with dedicated personnel, vehicles, and roads assigned. It is strictly forbidden for poultry keepers to cross-contaminate with the manure yard or manure removal personnel. Chicken manure should be removed the same day and transported out of the farm area the same day, strictly controlling pollution caused by chicken manure. At the same time, daily environmental cleaning and disinfection of the chicken farm and disinfection of chicken houses with chickens inside should be maintained. Poultry keepers and management personnel adopt closed management. Poultry keepers take a concentrated rest shift once every quarter. Unauthorized entry and exit from the production area is prohibited. Managers must shower before entering the production area, then change into dedicated work clothes, shoes, and hats before entering. Items entering chicken houses, such as egg boxes, feed bags, vehicles, and equipment, must all undergo strict disinfection.

A reasonable immunization program is the key to preventing the occurrence of infectious diseases. The formulation of an immunization program mainly refers to three factors: the rise and fall patterns of various antibodies in the chicken flock, the immune performance of various vaccines, and the epidemic situation of infectious diseases outside the farm. For example, in the Newcastle disease immunization program, based on the rise and fall patterns of maternal antibodies, at 7-10 days of age, the IV strain vaccine is administered via nasal drops and eye drops, along with the Newcastle disease oil emulsion inactivated vaccine. In this way, throughout the growing stage, especially during the 45-90 day age period when chronic atypical Newcastle disease is most prevalent, the Newcastle disease HI antibody titer of the chicken flock can be evenly maintained above 1:512, effectively controlling the occurrence of chronic atypical Newcastle disease during the growing stage. Before the onset of laying, a high-quality Newcastle disease, infectious bronchitis, and egg drop syndrome triple oil emulsion is once again administered via intramuscular injection, combined with attenuated or moderately virulent freeze-dried vaccine via drinking water immunization. In this way, throughout the entire laying period until culling, the Newcastle disease serum HI antibody titer of the chicken flock is maintained above 1:1024, thereby providing good protection throughout the entire laying period.

Strictly controlling the quality of vaccines and veterinary drugs and correctly using vaccines is the guarantee for preventing the occurrence of infectious diseases. Vaccine products produced by legitimate manufacturers must be purchased. Each batch of vaccines purchased must pass quality inspection before use. For example, Newcastle disease vaccine must pass vacuum detector inspection before potency testing. The hemagglutination (HA) titer of Newcastle disease IV strain vaccine must reach 1:160 or above, and the HA titer of Newcastle disease I strain must reach 1:80 or above before use. After vaccines are purchased and brought to the chicken farm, they must be kept by dedicated personnel. Vaccine preparation should be done in a sterile room, using dedicated diluent or sterilized physiological saline. Chicken flock vaccination should be strictly and conscientiously operated according to the prescribed methods and procedures. Unauthorized and arbitrary operations are strictly prohibited.

Carrying out a laboratory testing and forecasting system to guide timely immunization of chicken flocks is the safeguard against outbreaks of infectious diseases. Dedicated testing and laboratory personnel should be assigned, focusing on regular testing and forecasting work for infectious diseases that have not yet occurred. If signs of infection are found, vaccines should be administered immediately.

Through the above measures, large-scale outbreaks of various infectious diseases can be avoided, playing a protective and escorting role for the safe production of broiler chicken farms.