Phenotypic performance and response to selection for body weight gains of Black Bengal goat in a community breeding program

Black Bengal goat is a potential animal genetic resource of Bangladesh. The aim of this study was to investigate the genetic improvement of growth rate (GR) in-situ through a community based breeding program under a low input production system. Data on a total of 451 individuals from 2009 to 2015 in three generations were taken. In the community, two breeding strategies (BS); mating among superior bucks and does (BS1) and mating existing does with superior bucks (BS2) were followed. Mating among existing bucks and does (BS3) were considered as test group. The average GR from 0 to 3m, 3 to 6m, 6 to 9m, 9 to 12m and 0 to 12m were 43.05±0.78, 21.27±0.48, 21.42±0.37, 19.42±0.46 and 36.17±0.28 g/d, respectively. GR at different ages differed significantly (p<0.001) for sex, except at 0 to 3m. Generation and BS influenced GR at all ages significantly. Better growth rates were obtained in BS1 progeny and in later generations. The heritability (h2) estimates for GR at different ages ranged from 0.32 to 0.57. The genetic and phenotypic correlations for GR at different ages ranged from 0.02 to 0.87. The average responses for GR varied from 2.31 to 4.52 g/d per generation. It may be concluded that community based breeding program with superior bucks and does is very rationale under low input production system, as it improved growth performance in progressive generations. However, h2 and rG indicated scope of genetic improvement for GR if rigorous culling of inferior does and bucks can be adopted. Key words: Black Bengal goat, growth rate, genetic evaluation, response to selection.