Effects of kudzu vine (Pueraria lobata) on the intestinal microflora and volatile fatty acids in meat rabbits

Adding flavonoid-rich kudzu vine (Pueraria lobata) meal to animal feed can improve intestinal microflora. Here, we investigated the effects of kudzu vine meal on the growth performance, caecal microbial diversity, caecal microbial number, intestinal pH, and volatile fatty acids (VFAs) of meat rabbits. Two hundred weaned Ira rabbits were randomly divided into four groups and fifty rabbits in each group. Meat rabbits in the control group (group A) were fed a basal diet without kudzu vine meal; those in the three test groups were fed experimental diets comprising 15% (group B), 25% (group C), and 35% (group D) kudzu vine meal. The results showed that the daily feed intake and mortality of meat rabbits decreased significantly after adding kudzu vine meal to their diet. The feed-to-gain ratio and mortality rate in 35% kudzu vine dietary were 3.5 and 7.5%, respectively, significantly lower than those in the control group. The Shannon and Chao 1 index of the bacterial diversity decreased significantly after adding kudzu vine meal to their diet. With the increasing amount of kudzu vine meal, the variety of dominant phyla did not change, but the relative abundance increased with the increase of kudzu vine addition. The intestinal total VFAs, acetic acid and propionic acid were the highest in 15% kudzu vine dietary, and significantly higher than those of 25% kudzu vine dietary. The content of total bacteria in 35% kudzu vine dietary was the lowest and the Escherichia coli and Salmonella showed a decreasing trend. In conclusion, our study confirms the adding kudzu vine meal significantly decreased the mortality rates and feed-to-gain ratio of meat rabbits, and fed diets with 25%-35% kudzu vine meal are recommended to achieve optimal results in meat rabbits.