Practical recommendations on minimum and maximum fiber levels in rabbit diets

sixty rabbits NZW x Calfornian. of both sexes, weaned at four weeks of age were fed on four combinations of starter-finishing isonitrogenous-isocaloric diets : 7.20-10.50,10.50-14.09,14.00-17.05,17.5-20.81\% CF respectively. Growth and food intake were measured over 8 weeks. Carcass characteristics and economic evaluation were also carried out at the termination of the study. The experimental diets had significant influences on body weight and feed intake during the starter or finisher periods. Highest body weight and feed intake were recorded by rabbits of Group 3 (14.0-17.5\% CF) and that of Group 4 (17.5-20.81\% CF) respectively. Lowest weight gain and feed intake were recorded by rabbits of Group 1 which was fed on 7.2\% CF during the starter-grower period and switched on 10.5\% CF during the finisher one. Feed efficiency (FE) during the starter-grower period (p<0.01) (4-8 weeks of age) was. 2.484+/-0.145, 2.596+/-0.11, 2.740+/-0.06 and 3.116+/-0.066 feed(g)/gain(g) for Groups 1, 2, 3 and 4 respectively, while the corresponding ones of the finisher period (p<0.01) (8-12 weeks of age) was 2.966+/-0.071, 3.241+/-0.235, 3.420+/-0.026 and 4.205+/-0.116 respectively. The mortality rate (MR \%) during the first 4 weeks of the experimental period was: 26.67, 20.0, 6.6 and 6.6 for the experimental Groups 1, 2, 3 and 4 respectively, showing that MR was the highest (p<0.01) in the diet with the lowest fiber content (7.2\%) and the mediate one (20\%) attained with the 10.52\% CF after which it decreased to reach 6.6\% with the increase of CF (10.5 - 14.09 - 17.5\%). Carcass weights as percentage of live body weight were increased significantly (p<0.01) (52.16\%) with increasing CF level up to 14\% starter 8 17.5\% finishers after which it decreased (49.4\%) by increasing CF level. Maximum profit according to the present results could be obtained by using the maximum fiber level 14\% and 17.5\% during Starter finisher periods respectively. Therefore. from nutritional and economical point of view, the minimal fiber requirement of NZW x Californian. rabbits to avoid digestive disorders, increase in MR and to maximize their profit was found to be 10.52 CF during 4-8 weeks of age and 14.09\% CF during 8-12 weeks, and that of the maximal fiber one was found to be 14\% CF VS 17.5\% CF during the same periods.