Department of Genetics and Animal Breeding, College of Veterinary & Animal Sciences G.B.Pant University of Agriculture and Technology, Pantnagar-263 145. (UA)
* Part of M.Sc.Ag. (Animal Breeding), thesis submitted by the first Author to G.B.P.U.A.&T., Pantnagar-263 145
The data for the present study was taken from 740 pullets of a RIR strain, which were produced from 50 sires and 198 dams in 3 hatches. Mean values, heritability, estimates, genetic and phenotypic correlations were computed to evaluate the performance. The average of 20-WKBW, 40-WKBW, ASM, EP and 35-WKEW were found as 1395.68±5.05 g, 1673.24±5.64 g, 146.16±0.33 days, 107.19±0.10 eggs and 54.32±0.0089 g respectively. Pooled heritability estimates of the corresponding traits based on sire component of variance were 0.41±0.12, 0.40±0.12, 0.50±0.13, 0.70±0.16 and 0.40±0.12 respectively. The 20-WKBW was negative but significantly correlated with ASM at genetic and phenotypic levels. The genetic and phenotypic correlations of ASM with egg production and egg production with egg weight were negative but significant. Sixteen multitrait selection indices constructed using the above five traits in different combinations. Index I1, comprising of all the five traits was found to be most efficient. The reduction in ΔH values due to none inclusion of different traits in the index revealed that 40 week body weight, 20 week body weight, egg production, egg weight and age at sexual maturity were relatively less important in the given order. Further it was observed that selection based on the Index comprising of body weight at 20 and 40 weeks of age and egg weight was almost as efficient as index I1.
Economic traits, selection index, Rhode Island Red
