Effects of Glutamine on Growth Performance, Intestinal Morphology and Intestinal Barrier Function of Broilers

The effect of glutamine (Gln) on growth performance, intestinal morphology and intestinal barrier function were evaluated in broilers. A total of 320 birds were divided into a control group (CON) and three experimental groups (Gln 1, Gln 2 and Gln 3). Broilers of group CON received basal diet; broilers in group Gln 1, Gln 2 and Gln 3 were supplemented with 0.5%, 1.0% and 1.5 % Gln, respectively, for 42 days. The results indicated that Gln has no influence on the average daily gain (ADG) among the treatments in the periods of 1 to 21 d, 22 to 42 d and 1 to 42 d (P > 0.05). However, Gln improved average daily feed intake (ADFI) and feed intake: average daily gain (F: G), increased the villus height, villus height to crypt depth ratio (V/C) and the activities of sucrose, the ZO1, claudin-1 and occluding mRNA expression levels (P 0.05). Moreover, Gln decreased the crypt depth of jejunum and ileum in broilers at days 21 and 42 (P 0.05). In conclusion, Gln had a positive effect on growth performance and gut parameters by modifying the function of the intestinal mucosa barrier.