Genetic determinism of feed efficiency in rabbit: analysis of a selection experiment for two criteria of feed efficiency

Genetic parameters of feed efficiency and growth traits were estimated in two selected rabbit lines after 6 generations of selection. The ConsR line was selected for residual feed intake (RFI) under ad libitum feeding. The AlimR line was selected for average daily gain (ADG from 30 to 63 days) under restricted feeding corresponding to 80 % of ad libitum feed intake of control animals. Estimates of heritability of ADG and FCR (feed conversion ratio) were higher in the AlimR line than in the ConsR line, while estimates of heritability of weight at 30 and 63 days-old were similar between lines. Heritability of ADG (0.25), the selection criterion of the AlimR line, was higher than RFI (0.15), the selection criterion of the ConsR line. Estimates of heritability and genetic correlations between weaning weight, weight at 63 days, ADG and FCR are also presented for each line