Vol. 11, Special Issue 6 (2022)

Author(s):
Govind Singh Dhakad, Samita Saini, PK Mallick, PC Sharma, Navav Singh, Rakesh Kumar and Manoj Kumar

Abstract:
The aim of present study was to estimate (Co) variance components and genetic parameters of weight at birth (BWT), weaning (3WT), 6, 9 and 12 months of age (6WT, 9WT and 12WT, respectively) of Malpura sheep, maintained at Central Sheep and Wool Research Institute, Avikanagar, Rajasthan, India, by restricted maximum likelihood. Six different animal models with various combinations of direct and maternal effects were used. Data were collected over a period of 45 years (1975 to 2019). A log-likelihood ratio test was used to select the most appropriate univariate model for each trait, which was subsequently used in bivariate analysis. Heritability estimates for BWT, 3WT, 6WT, 9WT and 12WT were 0.15±0.02, 0.13±0.02, 0.18±0.02, 0.18±0.02 and 0.16±0.03, respectively. Maternal permanent environmental effect contributed 13% for BWT and 7% for weaning weight. There was no evidence for maternal permanent environmental effect on the post-weaning body weights. A moderate rate of genetic progress seems possible in the flock through selection. Direct genetic correlations between body weight traits were positive and ranged from 0.12 between BWT and 9WT to 0.80 between 3WT and 6WT. The high positive genotypic and phenotypic correlations between body weight at six months, nine months and twelve months of age indicates that selection for six months of traits will result in increase in nine and twelve months of body weight.