CONSTRUCTION AND EVALUATION OF MULTI-TRAIT SELECTION INDEXES FOR OVERALL ECONOMIC IMPROVEMENT IN WHITE LEGHORN LAYERS

Data collected on 1992 pullets produced in 3 hatches by mating 48 sires with 324 dams for age at sexual maturity, egg production up to 280 days of age, 32 weeks egg weights; body weight at 20 and 40 weeks of age were used for computation of multi-trait selection indices. On the basis of r(IH) values, and expected genetic gains (H), index I(l), wherein all the 5 traits were incorporated was most efficient, among the 26 selection indices evaluated. On the basis of reduction in r(IH) values, due to non-inclusion of different traits in the index, 40-week body weight, 20-week body weight, 32-week egg weight, egg production up to 280 days of age and age at sexual maturity were found to be important in that order.