Inheritance of bi-weekly juvenile body weight in IBI-91 broilers

The data utilised in the present study pertaining to 2126 progenies (1216 males and 910 females) from 44 sires of male line synthetic broiler (IBI-91) and 264 dams. The heritability estimates obtained from sire component of variance were 0.324±0.098, 0.179±0.068, 0.180±0.068, 0.40±0.113, 0.34±0.101, 0.31±0.095 and 0.36±0.1 07 for body weight at day old, two week, four week, six week, breast angle, shank length and keel length all measured at six weeks of age, respectively in males and the respective values in females were 0.464±0.127, 0.127±0.063, 0.164±0.070, 0.380±0.110, 0.330±0.101, 0.320±0.099 and 0.350±0.105. Genetic correlations were all positive between body weight at different ages. The estimates were larger when difference between age of measurement were smaller. Six week body weight was also found to be positively correlated with breast angle, shank length and keel length. All phenotypic correlations of six week body weight with other traits were also positive and significant in most instances. Environmental correlations were also positive as that of genetic and phenotypic correlations. Results suggested that individual selection for six week body weight would be highly effective to bring about improvement in six week body weight as well as in other correlated traits.