A comparative study on the effect of quantitative feed restriction in males and females of broiler chickens, rabbits and nutrias. I. Performance and carcass composition

The aim of the study was to compare the effects of feed restriction on the growth performance and carcass composition of chicken, rabbit and nutria males and females. Feed restriction was applied at a rate of 70% ad libitum from 14 to 21 days of age in chickens, 70% ad libitum from 42 to 49 days of age in rabbits, and 70% ad libitum from 12 to 15 weeks of age in nutrias. Animals were fed ad libitum prior to and following restriction. Carcass composition was evaluated at common slaughter ages, i.e., 31 days in chickens, 70 days in rabbits, and eight months in nutrias. The results showed stronger effects of feed restriction, sex, and their interaction in broiler chickens than in rabbits and nutrias. In chickens, feed restriction increased the sex differences in final body weight, which were associated with interaction of feed restriction and sex (P = 0.009). Feed restriction as a fixed factor significantly affected growth and feed conversion in chickens and it was with no effect in rabbits and nutrias. The effect of feed restriction on carcass composition was negligible in all selected species. With respect to sex, significant differences were observed in chickens in final body weight, daily weight gain, dressing out percentage and breast percentage, in rabbits in loin percentage, and in nutrias in growth and perirenal fat percentage. Results of the study indicated that interactions of feed restriction and sex in growth might be associated with a short realimentation period.