Combining ability analysis for certain economic traits in White Leghorn

A full 3 × 3 diallel experiment was planned utilizing three White Leghorn strains viz., IWH, IWI and IWK and the combining ability analysis was undertaken. The overall means for age at first egg, body weight at 20 and 40 weeks were 150.51±0.34 days, 1171.48±4.00 g and 1381.87±6.62 g respectively. Similarly the overall means of egg production up to 40 and 64 weeks of age and egg weights at 28, 40, 52 and 64 weeks of age were 98.74±0.70, 214.58±1.56, 47.77±0.11, 51.53±0.24, 54.40±0.13 and 56.57±0.15 g, respectively. The GCA effects were found to be significant for all the traits studied except for egg production up to 64 weeks of age. Similarly SCA effects were found to be significant for all the traits studied except for egg production up to 40 weeks. The reciprocal effects were significant for age at first egg, body weight at 20 weeks and for egg production up to 40 and 64 weeks of age. Heterosis for egg production up to 64 weeks and egg weight at 64 weeks was significantly favourable in five out of six crosses (based on mid parent). Hence strain crossing may be advocated to exploit the non-additive genetic variance in White Leghorns to bring about improvement in egg production and egg weight.