title: The detrimental effect of vaccinating parentally immune broilers with a modified liver virus vaccine for infectious bursal disease.
abstract: The experiment involved 392,955 broilers from breeders vaccinated with a commercially available killed infectious bursal disease (KIBD) virus vaccine (Treatments 1 and 2) and 373,371 broilers from breeders not vaccinated with a KIBD virus vaccine (Treatment 2). The broilers from the KIBD-vaccinated breeders were divided into two treatment groups: Treatment 1 consisted of 209,457 broilers and Treatment 2 consisted of 183,498 broilers. Treatment 2 broilers were vaccinated at 10 days of age intraocularly with a commercially available modified liver infectious bursal disease virus (IBD-MLV) vaccine. Broilers in all three treatments were raised on commercially contracted farms serviced by the same company representative. Broiler performance was based on mortality, body weight, feed efficiency, condemnations, and how each farm ranked with respect to contract settlements. Compared with birds in Treatments 2 and 3 respectively, Treatment 1 broilers had 1.65% and 0.89% less mortality; 0.22 lbs. and 0.09 lbs. increased weight per bird; 0.03 and 0.03 increased feed efficiency; 0.09% and 0.32% fewer air sacculitis condemnations; and 0.57% and 0.83% fewer total condemnations. Treatment 1 broilers ranked in the top 37%; Treatment 2 ranked in the bottom 36%; and Treatment 3 ranked in the lower 57% of contract settlements for all broilers processed. The results clearly showed that Treatment 1 broilers outperformed Treatment 2 amd 3 birds and that the IBD-MLV vaccine had a detrimental effect on Treatment 2 broilers.
mesh_terms: D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000254:growth & development / Q000276:immunology*; D007112:Immunity, Maternally-Acquired; D007243:Infectious bursal disease virus / Q000276:immunology*; D011201:Poultry Diseases / Q000517:prevention & control*; D012087:Reoviridae / Q000276:immunology*; D012088:Reoviridae Infections / Q000517:prevention & control / Q000662:veterinary*; D014611:Vaccination / Q000662:veterinary*; D014765:Viral Vaccines / Q000009:adverse effects*
chemical_list: D014765:Viral Vaccines