Estimation of genetic parameters for production traits in Munjal sheep

Abstract

Astudy was carried out to estimate the genetic parameters of production traits in Munjal sheep using 16 years (2001–2016) data of 462 sheep maintained at Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar Mixed model analysis included the sire as a random effect and effects of period of birth, sex, dam's age at lambing as fixed effects. Heritability estimates and genetic correlations for different traits were calculated by paternal half-sib correlation method using sire components of variance and covariance. Period of birth and sex of lamb had significant effect (P<0.05) on all traits except greasy fleece weight (GFW). Dam's age at lambing had significant (P<0.05) effect only on birth weight. The overall least squares means of production traits recorded for birth weight (BW), weaning weight (WW), six months body weight (SMW), yearling body weight (YBW) and annual GFW were 4.1±0.07, 15.57±0.22, 20.79±0.53, 26.40±0.41 and 1.84±0.04 kg, respectively and the corresponding heritability estimates were 0.35±0.18, 0.48±0.20, 0.57±0.24, 0.48±0.25 and 0.52±0.22, respectively. Genetic correlations among production traits were positive and low to high in magnitude (0.10±0.05 to 0.76±0.05) and the highest genetic correlation of 0.76±0.05 was found between SMW and YBW. Phenotypic correlations among various production traits were found to be positive and significant ranging from 0.17±0.04 to 0.81±0.03. It was concluded that selection on the basis of SMW would be the best approach to improve growth performance in Munjal sheep as the trait has high heritability and positive genetic correlation with other body weights.