title: Incidence of avian leukosis virus infection in broiler stocks and its effect on early growth.
abstract: Twenty-eight broiler breeder flocks were tested for avian leukosis virus (ALV) group-specific (gs) antigen shedding into the albumen. The rate of shedding ranged from 0 to 17%, rates substantially lower than those observed previously in egg production stocks. The flock shedding at the highest rate was trap nested and dams positive and negative for gs antigen shedding in the albumen produced progeny for a growth trial. Chicks produced by the positive and negative dams had 27 and 1% ALV isolations from their meconia, respectively. Progeny of positive dams or chicks having virus in their meconia weighed 1 to 3% less at 4 and 7 weeks than progeny of negative dams. More infected chicks died or were runted by 7 weeks. Although the proportion of infected chicks and the lower weight gain is very small, the previously reported loss in breeder flock productivity and livability suggest broiler breeders should consider reducing ALV shedding in higher incidence female lines.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000302:isolation & purification; D001353:Avian Leukosis / Q000453:epidemiology* / Q000635:transmission; D001354:Avian Leukosis Virus / Q000276:immunology / Q000302:isolation & purification; D001835:Body Weight; D002645:Chickens / Q000254:growth & development*; D003168:Complement Fixation Tests / Q000662:veterinary; D005243:Feces / Q000382:microbiology; D005260:Female; D008297:Male; D010047:Ovalbumin / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D010047:Ovalbumin