COMPARISON OF GROWTH AND FEED-EFFICIENCY AMONG RABBIT LINES SELECTED FOR DIFFERENT OBJECTIVES

An experiment has been carried out to evaluate correlated responses in feed efficiency in lines selected for postweaning, daily gain and lit ter size, respectively. One sire line, selected for growth rate for 19 generations, and two dam lines, selected for litter size at weaning f or 14 and 18 generations, have been compared for weaning weight (28 d) , daily gain (28-63 d), feed intake and feed conversion. Large differe nces between the sire line and the dam lines are expected for the last three traits as a result of the different methods of selection. The m ost important estimated differences between lines during the postweani ng growth period (weaning at 28 d, and slaughter at 63 d) were: The si re line grew about 9 g/d (24%) faster than the dam lines, had a greate r feed consumption of 17 g/d (14%) and a lower feed conversion rate of 0.33 (11%), Selection of the sire line for growth rate is suggested a s the main cause of the differences between the lines.