Inheritance of Viability of Pullets in the Laying House

HIGH viability of pullets in the laying house is one of the most important qualifications of a superior flock. For a considerable period of time, attention of many workers has been directed toward the value of selective breeding as a tool to increase viability. Recently Moultrie, King and Cottier (1953) have reported very significant progress in reducing mortality through selective breeding. Many other workers have made valuable contributions. Their work is cited by the Alabama workers and need not be reviewed here. Most pedigree breeders now include viability in their selection program. Since selective breeding has been effective in reducing mortality, it seems very probable that hereditary factors may be in operation. Due consideration should be given, however, to such important environmental factors as exposure to and contraction of diseases and parasites, protective vaccinations, medicinal treatments, nutrition, housing, and general management, all of which may affect the death rate. Breeding …