Estimation of genetic parameters of various economic traits in a closed population of female line layer type chickens under short term selection

The genetic parameters for various traits of economic importance were studied in a female line of chicken population under short term selection for egg production for over 2 years. The parameters studied were body weight at 20 (BW20) and 40 weeks (BW40), egg weight (EWT) and egg 280 days; and they showed mostly moderate to high heritability estimates. All these values were 0.16 to 0.78, 0.11 to 0.23, 0.42 to 0.66 and 0.25 to 0.62 respectively. Higher heritability estimate were obtained from the sire component for BW20 (0.78), BW40 (.23) and egg 280 days (0.62). However, a higher estimate was obtained from the dam component for EWTAV (0.66). Body weight at 20 weeks of age shows positive genetic and phenotypic correlations with BW40 (0.77 and 0.28) and egg 280 days (0.51 and 0.02). BW40 had positive genetic and phenotypic association with EWT (0.12 and 0.23) and egg 280 days (0.68 and 0.20). However, EWT showed negative genetic as well as phenotypic correlation with egg 280 days (-0.15) and (- 0.09).