CONSEQUENCES OF SELECTION FOR POST-WEANING GROWTH PERFORMANCE ON CARCASS ATTRIBUTES IN RABBITS

Abstract

The aim of this work is to investigate the consequences of selection for post-weaning growth performance on carcass composition and carcass meatiness traits. Seven selection indices were applied using estimates of genetic and phenotypic parameters on 218 New Zealand White (NZW) rabbits, progeny of 24 bucks and 93 does, via a multi-trait animal model. Slaughter weight (SW) and daily gain between them (DG) were used as sources of information. The breeding objective was to enhance the profitability of NZW rabbit breeders by maximizing and The carcass composition was represented as the percentage of dissected side weight deposited as muscle (MP), Fat (FP), and bone while carcass meatiness traits were represented as carcass muscle: bone ratio (MB), and muscle: fat ratio (MF). The heritability estimates (h 2 ) were 0.69, 0.44 and 0.54 for WW, SW and DG, respectively. Carcass composition traits showed moderate estimates of h 2 for MP (0.31) and FP (0.35) and a very high value for BP (0.91). The h 2 values for carcass meatiness traits were 0.42, 0.43, 0.89, and 0.75 for CW, DP, and from -0.43 to -0.31 unit). Carcass meatiness traits are expected to be more favorable in terms of higher DP (ranged from 0.14 to 0.38 unit) and MB ratio (ranged from 0.28 to 0.36 unit) and less favorable in terms of MF (ranged from -0.23 to -1.60 unit). Conclusively, the results obtained in the present study suggested that selection based on the single trait index I 5 including the weaning weight trait would be recommended to improve the given aggregate genotype traits for being an early, single, and easy-to-measure.