Genetic and phenotypic performance of three coat color variants of Black Bengal Goat in a closed nucleus flock at BLRI

Abstract

SMJ Hossain, MF Afroz, MA Habib, MFH Mirazand MA Jalil

The objective of this study was to evaluate comparative performance of three coat color variants of Black Bengal Goat. The research was conducted under semi-intensive management system and data were analyzed statistically with R packages and VCE animal model. Irrespective of sex, color type (CT), litter type (LT), kidding parity (KP) and kidding season (KS), overall mean values of birth (BWT), one (1MWT), three (3MWT), six (6MWT) month body weight, growth rate at 0 to 3 (GR0-3) and 3 to 6 (GR3-6) month were 1.14±0.02, 3.52±0.09, 7.24±0.18, 11.64±0.41kg, 58.02±2.02 and 48.80±2.83g/d, respectively. CT had p<0.05 effect on 3MWTand 6MWTand p<0.001 on GR0-3, Whereas LT had on BWT p<0.001 and 6MWT p<0.05 effect. Sex, KP and KS had no significant effect on all body weight (BW) traits. Irrespective of CT and KP, overall mean values of age at puberty (AP), age at first kidding (AFK), number of services per conception (NSPC), litter size (LS), post-partum heat period (PPHP) and kidding interval (KI) were 215.5±15.6 d, 374.5±20.0 d, 1.25±0.05 no., 2.37±0.09 no., 43.3±4.01 d and 210.6±7.34 d, respectively. CT had no significant effect on all reproductive traits (RT). KP had p<0.001 effect on LS. The BW and GR traits exhibited medium h 2 estimates ranging from 0.463 to 0.493. All RT showed low estimates of h 2 ranging from 0.002 to 0.159, except that of AP (0.490). The strengths of rg andrp correlations among BW and GR traits were medium to strong (p<0.01) with positive direction among most pairs of traits. The rg andrp correlations between 6MWT and AP existed to be significantly (p<0.05) medium strength -52.0% and- 39.4%. On the other hand, correlations between 6MWT and LS appeared to be significantly (p<0.05) medium strength +46.1% and +46.9%. The rg andrp between AP and LS was very low. rg among BW traits indicate that selection of animal based on BWT may have very little chance of improvement for other traits as rg and rp between BWT with weights at other ages are low. However, due to strongly positive rg between 3MWT and 6MWT, early selection at 3MWT could be helpful for breeding purpose in future genetic improvement program.