Effect of genetic and non-genetic factors on performance traits of egg type chickens
SANDEEP NARVAL, C.P.MALIK, Z.S. MALIK AND Z.S.RANA
Department of Animal Breeding, CCS Haryana Agricultural University
This study was conducted on 1672 pullets, belonging to H and C strains of White Leghorn produced from 191 sires mated to 919 dams in different hatches over six generations. The data were used to study the effect of strain, generation and ‘hatch within generation’ on performance traits. The performance traits recorded were body weights at 20 and 40 weeks of age (BW20, BW40), age at first egg (AFE), egg production upto 40 weeks of age (EP40), egg weight at 40 weeks of age (EW40), clutch size upto 30 weeks of age (CS1) and clutch size from 31 to 40 weeks of age (CS2). Data were analysed by using Harvey’s least squares technique. Strain had significant (P≤0.01) effect on BW20, AFE, EP40 and CS2 and non-significant on BW40, EW40 and CS1. Generation and hatch within generation had significant effect (P≤0.01) on all the traits except that hatch within generation had non-significant effect on CS2. Least squares means for BW20, BW40, AFE, EP40, EW40, CSI and CS2 were 1232.18g, 1505.53g, 148.29 days, 91.62 eggs, 54.65g, 2.71 eggs and 2.77 eggs, respectively, in H strain and 1243.20g, 1512.03g, 149.65 days, 89.63 eggs, 54.62g, 2.62 eggs and 2.45 eggs, respectively in C strain. These results suggest that data should be analysed for both strains separately and should be corrected for ‘hatch effect within generation’ to get precise estimates of genetic and phenotypic (co) variability for these traits.