Genetic analysis for growth traits of prolific Garole x Malpura (GM) sheep

The FecB gene of Garole sheep was introgressed into non-prolific Malpura sheep to evolve a new prolific sheep strain Garole x Malpura (GM), suitable for semi-arid conditions. The present study was conducted to evaluate the impact of breeding program on production profile of GM sheep and to estimate the genetic parameters for growth traits of GM sheep. Overall prolificacy increased significantly in the new strain as compared to the native Malpura sheep. In the GM flock of F2 and F2 onwards generation 35.31% single, 55.83% twins, 8.16% triplet and 0.70% quadruplets were obtained during lambing. Over the years, prolificacy in the flock has increased significantly. Over all least squares means for birth weight, 3, 6, 9, 12 month weight, pre-weaning gain (ADG1) and post-weaning gain (ADG2) were 1.82+/-0.03, 9.44+/-0.18, 14.00+/-0.24, 16.56+/-0.33, and 19.32+/-0.35 kg, and 84.08+/-1.84 and 35.19+/-0.99 g, respectively. Majority of the fixed effects had significant influence on the performance traits. The heritability estimates for birth, 3, 6, 9, 12 month weight, ADG1 and ADG2 were 0.30+/-0.11, 0.22+/-0.09, 0.23+/-0.10, 0.27+/-0.10, 0.30+/-0.11, 0.17+/-0.08, and 0.17+/-0.10, respectively. Modest rate of genetic progress seems possible for these traits under selection. The genetic and phenotypic correlations among different body weights were moderate to high and positive. The genetic correlation of pre and post-weaning daily gains with body weight traits were also high and positive.