Relation of Age of Parents to Mortality and Sex Ratio of Chicks at Eight Weeks

Abstract

PHYSIOLOGICAL characters are very important in breeding poultry for egg production, viability, and disease resistance. For the most part these characters have a low degree of heritability necessitating the use of progeny testing which requires old parents for reproduction. Longevity also offers something of a measure of viability, and family mortality rate affords a useful tool to guide the breeder. This study was undertaken first to discover possible relations between age of parents and the viability of their offspring to eight weeks of age. It was desirable also to learn whether age of parents has any effect on the sex ratio of chicks at eight weeks of age. Observations on the effect of this early mortality on the sex ratio at the age of eight weeks would also be useful. LITERATURE REVIEW Pearl (1940) reported the mortality rate in infants from 20 countries during the first year of life as . . .