Genetic evaluation of broiler dam line
Abstract
Data over 13 generations collected from the record of broiler dam line maintained in the Department of Animal Breeding, CCS Haryana Agricultural University, Hisar was analyzed to estimate genetic and phenotypic parameters and response to selection in broiler for production and reproduction traits.
The heritability of body weight at 20 and 40 weeks of age was moderately heritable, egg number upto 40 and 50 weeks of age were low to moderate while age at first egg, egg weight, clutch size and pause size are low heritable traits.
BW20 had positive high association with BW40, E.W, C.S and negative with AFE, EN40, EN50, P.S both at genetic and phenotypic level. Age at first egg was negatively associated but low magnitude with EW, EN40, EN50 and pause size both at genetic and phenotypic level. Negative association was found between egg weight and egg number and pause size. Positive high association among egg number upto 40 and 50 weeks of age was observed both at genetic and phenotypic level. Genetically clutch size was positively associated with pause size while relatively low at phenotypic level. Mass selection for broiler body weight is expected to increase body weights at both ages but decrease in AFE and egg production upto both ages.
Accuracy of selection was maximum for the I3 index (0.70). Maximum response in EN40 was expected from the selection of pullets based on I3 index. Selection of cockerels was expected to increase EN40 by 4.79 eggs, EW by -0.48g and AFE by -0.32. Maximum response in EN50 was expected from the selection of pullets based on I3 index minimum reduction in egg weight was expected from I1 index. Selection of cockerels was expected to increase EN50 by 5.01 eggs, EW by -0.28g and AFE by -0.47 days. An optimum weight of about 2000g at 20 weeks of age for pullet which mature at 145 day will lay maximum eggs.