Effect of feeding programme on performance and health of growing rabbits

The effects of two feeding systems (L, ad libitum vs. R, feed restriction) combined with three diets (HH, a high digestible energy diet, 11.1 MJ DE/kg, during the whole trial vs. MM, a moderate DE diet, 10.7 MJ/kg, during the whole trial vs. MH, a moderate DE diet during the first three weeks and a high DE diet during the last two weeks) were evaluated in 252 commercial crossbred rabbits kept individually from weaning to slaughter (34 to 70 d of age). The restricted rabbits were fed from 85% of the theoretical ad libitum intake at the beginning of the trial to 100% of the ad libitum level at the end of the 3th week. During the first week, growth rate was impaired by feed restriction (53.6 and 46.8 g/d in L and R rabbits, P<0.001) because of the lower feed intake (107 vs. 93 g/d). During the second week, the appearance of digestive disorders in L rabbits reduced the difference in feed intake with R groups (134 vs. 129 g/d, P=0.05) and growth rate was similar in the two groups. During the third week, L rabbits had similar feed intake (151 vs. 148 g/d, P>0.10) and lower growth rate compared to R rabbits (48.2 vs. 51.3 g/d, P=0.05). During the fourth and fifth weeks, neither growth rate nor feed intake differed between the two groups. In the whole trial only feed conversion was improved by feed restriction (2.96 vs. 2.89 in L and R rabbits; P<0.01) and by the high-DE program (2.89 vs. 2.93 and 2.97, for HH, MH and MM groups, respectively; P<0.05). Morbidity was lower in the restricted group (5.5% vs. 2.4% in L and R rabbits; P<0.001) and in HH and MM groups compared to MH group (3.6% and 2.4% vs. 5.9% respectively; P<0.001). In conclusion, feed restriction improved feed efficiency and health, whereas the change from a moderate to a high energy diet during the growing period could impair rabbit health.