Effects of Genotype and Quantitative Feed Restriction on the Post-weaning Growth Traits of Rabbits

The purpose of this paper is to determine the effects of four genotypes and four different quantitative feeding regimes on the post-weaning average feed intake (AFI), body weight (BW), weight gain (WG) and feed conversion ratio (FCR) of 48 unsexed weaner rabbits. At weaning, a total of 3 rabbits from each genotype considered, namely the purebred Chinchilla and New Zealand White (CH x CH, NZW x NZW) and their reciprocal crossbreds (CH x NZW, NZW x CH), were randomly assigned to four feeding regimes: ad libitum concentrate + ad libitum forage (A), ad libitum concentrate + 30% restricted forage (B), 30% restricted concentrate + ad libitum forage (C), and 30% restricted concentrate + 30% restricted forage (D). The data were subjected to a two-way analysis of variance in a completely randomized design appropriate for a 4x4 factorial experiment. The experiment was conducted over a period of 5 weeks: from 7 to 11 weeks post-weaning. The AFI values obtained from the interactions between CH x CH and the C feeding regime at 7 weeks post-weaning (366.50 ± 1.50 g), and between NZW x NZW and the B feeding regime at 8 weeks (324.00 ± 1. 00 g) and 10 weeks post-weaning (336.50 ± 0.00 g) were similar, but differed significantly (P < 0.05) from the rest. The lowest significant AFI values (P < 0.05) at all ages and FCR values (3.46 ± 0.33) at 9 weeks post-weaning were obtained from NZW x NZW, whereas the highest BW values at 9-11 weeks post-weaning was obtained from CH x CH. The lowest significant AFI values (P < 0.05) were recorded in the B feeding regime at 7-11 weeks post-weaning, as well as the highest BW and WG values in the A feeding regime at 8–11 and 11 weeks post-weaning, respectively. Moreover, the highest significant BW values (781.25 ± 7.83) were recorded in the C feeding regime at 7 weeks post-weaning. It was concluded that the interactions between CH x CH and the C feeding regime and between NZW x NZW and the B feeding regime can significantly reduce the overall feed intake, thus invariably increasing profit in rabbit production.