RESPONSE TO SELECTION FOR GROWTH RATE IN RABBITS ESTIMATED BY USING A CONTROL CRYOPRESERVED POPULATION

Abstract

An experiment of selection for growth rate in rabbits was carried out. Response to selection was estimated by analyzing a mixed model and estimating the genetic effects of the animals in each generation, and also by comparing the last generation of selection with a control population. Animals originated from a synthetic rabbit line. Embryos from generations 3 and 4 were frozen and thawed in order to be contemporaries of rabbits born in generation 10. Group C was the offspring of generations 3 and 4, and group S was the contemporary offspring of generation 10. Random samples of the posterior distributions of the growth genetic parameters were drawn by using Markov Chain Monte Carlo methods. The heritability of daily gain was 0.11 (with an s.d. of the marginal posterior density equal to 0.02). At commercial slaughtering age (9 wks old), selected animals had a higher growth rate (49.8 g/d, s.d. 0.75 vs. 45.9 g/d , s.d. 0.76) and slaughter weight (2350 g, s.d. 34 vs 2180 g, s.d. 40). Both methods of estimating the selection response yielded similar results.