Specific prophylaxis against infectious bursal disease of chickens in industrial poultry farms

The infectious bursal disease (IBD) of chickens is currently registered in all countries of the world. It is a serious problem for industrial poultry farming due to the high economic damage caused by mortality. The average mortality rate is 40-80% in young egg-laying chicken breeds and 30-40% in broilers. The most effective measures against IBD are a specific prophylaxis with live virus vaccines. The aim of the research was to study the effect of specific prophylaxis against IBD on productivity indicators when feeding broilers. The results of the experimental use of three specific prophylaxis schemes are analyzed in the study. The following vaccines against IBD were used: live vaccines based on the “MB” strain, “Bursaplex” and “Bursin Plus”. The first scheme, which is the control one (used at the enterprise), was a single use of a live vaccine from the “MB” strain by bottle-feeding chickens on the 14th day. The second experimental scheme was the introduction of the “Bursaplex” vaccine by in ovo method into embryos of 18-19 days of incubation and subsequent revaccination on the 15th day by bottle-feeding the chickens with the “Bursin Plus” vaccine. The third experimental scheme was similar to the second one, but excluding revaccination with the “Bursin Plus” vaccine. It was found out that the most positive effect on productivity indices during broiler fattening was made by the third scheme of specific prophylaxis against IBD with the intra-embryonic use of the “Bursaplex” vaccine (without revaccination). The European productivity index of this scheme is 18.3% higher in comparison with the second scheme including revaccination with the “Bursin Plus” vaccine and 8% higher in comparison with the first (control) scheme using the live vaccine “MB” strain.