Reproductive Peculiarities and Litter Weight in Different Genetic Groups of Black Bengal Does

Three genetic groups of Black Bengal does in each of two successive generations were evaluated for reproductive characteristics (age and weight at first heat, litter size, kidding interval), fertility indices (service per conception, post partum heat period) and biomass (litter weight) production. Three genetic groups were: crossbred (Jamnapari ♂ ♂ Black Bengal ♀ ♀, JBB1), Black Bengal selected for heavier live weight (SBB1) and randombred Black Bengal (RBB1) in fiist generation (G1); and crossbred (JBB1 × JBB1=JBB2), selected Black Bengal (SBB2) and randombred Black Bengal (RBB2) in second generation (G2). Age at first heat were 319, 250 and 241 and 362, 242 and 259 days for crossbred, selected and randombred Black Bengal does in G1 and G2 respectively. Crossbreds differed from purebreds both in age and weight at first heat. Selection did not affect age but increased weight at first heat only in G1. Litter size was lower in crossbreds than in purebreds. Post partum heat period (d) was longer in crosses (107) than in purebreds (70, 84) only in G2. Selected goats in G1 produced heavier 60d litter biomass than the other two groups. Selection for better growth did not significantly affect reproduction and fertility traits but crossbreeding disfavoured them. It was inferred that to get more flock output at an earlier age, selection is more useful than crossbreeding in Black Bengal goats.