The Effect of Lactobacillus isolates on growth performance, immune response, intestinal bacterial community composition of growing Rex Rabbits

The objective of this experiment was to investigate the effect of Lactobacillus isolates on intestinal bacterial community composition of growing Rex Rabbits. A total of 120 weaned Rex Rabbits (30 days old, 30 per group) were used for the experiment, which started after an adaptation period of 7 days. The control group was fed with basal diet only, while the treatment I, II and III groups were fed with basal diet adding antibiotics, Lactobacillus zeae (LB1) and Lactobacillus casei (L3) respectively. Growth performance, immune response and intestinal flora have been examined. The results obtained were as follows: (i) F/G of the rabbits fed with Lactobacillus isolates was significantly lower than that of the control group (p < 0.05). (ii) The concentration of ALT decreased significantly (p < 0.05) and that of IgG and IgM increased significantly (p < 0.05) after feeding rabbits with Lactobacillus isolates. (iii) Lactobacillus isolates had no influence on the number of mast cells in duodenum and jejunum, but increased the number of mast cells in caecum significantly (p < 0.05). (iv) The data from pyrosequencing-based analysis suggested that the bacterial community in the rabbit's intestinal flora can be changed by Lactobacillus isolates and antibiotics, especially for the microbial diversity and abundance in the caecum. In conclusion, the application of proper Lactobacillus isolates can improve the growth performance, enhance the immunological function and adjust the intestinal micro-ecosystem of growing Rex Rabbits.