Heritability of Chick Viability for Two Breeds of the Domestic Fowl

INTRODUCTION THE few reports which are available suggest that heritability of chick viability is extremely low. Wilson (1948) estimated heritability of viability to 8 weeks of age on an inbred flock of White Leghorns as 11.8 percent and after correction for inbreding this figure was reduced to 5.2 percent. Hale (1954), using records of a White Wyandotte flock collected for a period of six years, estimated heritability for the period up to 8 weeks as 7.4 percent (betweens sires) and 14.3 percent (between dams). Brunson et al. (1956) have used the period from hatching date to 10 weeks of age to provide their average figure of 5 percent based on two breeds and their reciprocal crosses. More recently, Dickerson (1957) obtained estimates of 2 percent and 13 percent respectively, from paternal half-sib and. full-sib correlations for the period from 0-10 weeks. All the above estimates are in close agreement. MATERIALS …