Effects of rabbit sacculus rotundus antimicrobial peptides on the intestinal mucosal immunity in chickens

Ninety chickens were randomly divided into 2 groups (45 chickens in each group) to determine the effect of oral administration of rabbit sacculus rotundus antimicrobial peptides (RSRP) on the intestinal mucosal immune responses in chicken. On d 7, 14, 21, and 28, the animals received 0.1 mg of RSRP dissolved in 0.5 mL of physiological saline. The control groups received the same dose of physiological salt solution on the same day. The results showed that RSRP increased the villus height of the duodenum (P < 0.01) and jejunum (P < 0.05) at the ages of 28, 42, and 56 d. The numbers of intestinal intraepithelial lymphocytes in different parts of intestine of the RSRP group were increased significantly more than that of the control (P < 0.01 or P < 0.05) at the ages of 28, 42, and 56 d. The RSRP increased the area of IgA-secreting cells of each fragment of intestine at all 3 time points. These results indicated that the presence of RSRP affected and considerably modified the structure of the intestine and mucosal immune parameters in healthy chickens when compared with controls.