Inheritance of body weights and egg production in White Leghorn

The perfonnance records of 377 pullets produced from 20 sires and 220 dams of a closed flock of White Leghorn (WLH) were utilized for the present study. Means, heritability estimates and genetic and phenotypic correlations were computed. The genetic and phenotypic covariances obtained from sire + dam components were utilized for the construction of selection indices. Four selection indices were constructed utilizing 20-wk body weight, age at sexual maturity and 90-day egg production. Comparisons were made based on correlation between index and aggregate genetic gain (r_IH) and aggregate genetic gain (ΔH). The most efficient index was three-trait index incorporating 20-week body weight, ASM and 90-day egg production.