Influence of additive and non-additive gene effects on body measurements in the domestic rabbit

Abstract

General Combining Ability (GCA) and Specific Combining Ability (SCA) were used to determine the influence of additive and non-additive gene effects on growth parameters, using 2 kits produced in full diallel crosses involving three breeds of rabbits namely, New Zealand White (NZW), Dutch (DT) and Chinchilla (CH). GCA was significant (P<0.05) for four out of the twelve traits studied, namely Body length (BL), Heart girth (HG), Ear length (EL) and Tail Length (TL). GCA values ranged from-12.594 for body weight (BWT) to 0.041 for the length of the hind limb (LHL) for NZW, -3.836 for BWT 10 0.123 for Head Circumference (HC) for DT and -0.035 for Head-to-shoulder (HS) and 16.431 for BWT for Chinchilla. SCA was significant (P<0.05) for HS only. SCA estimates ranged from -0.016 (BWT) to 0.187 (HG), 1.018 (BL) to 10.22 (BWT) and -17.09 (LHL) to 7.354 (BWT). for NZW x DT, NZW x CH and DTX CH crosses, respectively. The significant GCH observed in the four growth parameters indicates that genes governing them aci mainly additively. This implies that they may be genetically improved by selection and pure breeding. Significant SCA for HS is an indication that genes governing this character impart non-additive effects, suggesting that improvement could be brought about by exploiting crossbreeding and by improving the environment.