The effect of selection for growth rate on carcass composition and meat characteristics of rabbits

The effect of selection for growth rate on carcass composition and meat quality was assessed by comparing two groups of rabbits belonging to different generations of a selection experiment. A Bayesian approach was used. Embryos belonging to generations 3 and 4 of selection were frozen and thawed to be contemporary of animals from generation 10. A control group (C), formed from offspring of these embryos, was contemporary to offspring of generations 10 and 11 of selections, chosen at random, which constituted the selected group (S). One hundred and thirty-one contemporary rabbits were slaughtered at approximately the Spanish commercial live weight of 2 kg. Carcasses were dissected and measured according to the norms of the World Rabbit Scientific Association. An animal model including effects of genetic group (C,S) and sex, and slaughter weight as a covariate was used. S animals had a higher development of liver, kidneys and of a set of organs consisting of the thymus, trachea, oesophagus, lung and heart, relative to C. For dissectible fat, S animals had less than C: -0.31 g for scapular fat, -1.62 g for perirenal fat and -2.03 g for inguinal fat. S had a lower content (-0.39%) of dissectible fat percentage in the "Reference" carcass, indicating a lower degree of maturity at slaughter. The meat to bone ratio was not affected by selection, but the meat and bone contents of the hind leg were 3.25 and 0.71 g higher, respectively, in the C group. Selected animals had a lower water holding capacity in the raw meat (-2.10%), a higher water holding capacity in the cooked meat (2.17%), a higher cooking loss (3.31%) and a lower fat percentage in the meat of a hind leg (-0.37%). Females had more fat than males: 0.26 g for scapular fat, 1.02 g for perirenal fat, 1.10 g for inguinal fat, and 0.24% for total dissectible fat percentage of the "Reference" carcass.