Abstract:

We investigated the effect of dietary supplementation with kudzu vine （Pueraria lobata） on the growth and quality of meat rabbits. A total of 200 weaned Ira rabbits with similar body weight （0.88±0.13 kg） at 35±2 days of age were randomly divided into four groups with five replicates in each group and 10 rabbits in each replicate. The rabbits were fed with diets containing 0 （Group A）， 15% （Group B）， 25% （Group C）， and 35% （Group D） kudzu vine， where Group A was the control group. The experiment consisted of a 7-day pretest period， followed by a 42-day trial period. Starting from day 36 of the trial period， a 7-day digestion and metabolism test was conducted to analyze the apparent digestibility of nutrients in the diets of meat rabbits. Intestinal development and the activities of intestinal digestive enzymes were determined and analyzed at the end of the test. A conventional nutrient analysis was conducted for kudzu vine. It was found that： 1） The apparent digestibility of nutrients （dry matter， crude protein， crude fiber， neutral detergent fiber， acid detergent fiber， acidic lignin， ether extract， and galacturonic acid） by meat rabbits was higher in the treatment groups than in the control group. The apparent nutrient digestibility was highest in Group D （35% kudzu vine）， and it was significantly higher than that in Group B （15% kudzu vine） and the control group （P<0.05）. 2） The activities of cellulase， hemicellulose， and pectinase in the cecum of meat rabbits were higher in the treatment groups than in the control group. The activities of these enzymes were highest in group B （15% kudzu vine）， and were significantly higher than those of their counterparts in the control group （P<0.05）. 3） Dietary supplementation with kudzu vine had no effect on the relative length of the stomach and small intestine of meat rabbits （P>0.05）. However， the relative length of the cecum， relative weight of the cecum， relative weight of the stomach， and relative weight of the small intestine were significantly higher in Groups C and D （25% and 35% kudzu vine， respectively） than in the control group （P<0.05）. 4） Dietary supplementation with kudzu vine increased the villus length of the jejunum， ileum， and duodenum， villus length/crypt depth （V/C） ratio， and the mucosal thickness of meat rabbits， and decreased the crypt depth. Compared with the control group， Group D （35% kudzu vine） showed significantly higher values （P<0.05） for villus length of the ileum and duodenum，lower values for the crypt depth of the jejunum and ileum， and significantly higher values （P<0.05） for the V/C ratio of the jejunum and ileum. Therefore， dietary supplementation with 35% kudzu vine is optimal for Ira meat rabbits.

Key words: Ira rabbits, kudzu vine, nutrient apparent digestibility, intestinal development, digestive enzyme activities