Levamisole improves histomorphometric parameters of small intestinal wall of broiler chickens

Abstract

Sixty one-day old chickens were divided into 6 equal groups and treated with 0, 2, 5, 10, 15 and 25 mg/kg levamisole from day 1 to 45. Then, all birds sacrificed and samples were taken from duodenum, jejunum and ileum. Cross-sections were made and H&E stained. Histomorphometric parameters including villus height, crypt depth, villus width, sub mucosal width, muscular layer width and the villus height/crypt depth ratio were determined. Duodenal villi became wider in all levamisole treated groups but only the highest dose resulted in taller villi. Jejunal villi became taller without significant change in their width. This was accompanied by a decrease in crypt depth and increased villus height/crypt depth ratio in all treated groups. In ileum, only birds treated with the highest dose had higher villus height, although levamisole at all doses resulted in wider villi. Sub mucosal width increased in birds treated with 15 and 25 mg/kg levamisole. In conclusion, levamisole can improve histomorphometric parameters of small intestinal wall of broiler chickens. This can partly explain the mechanism for previously described positive effects of levamisole on performance of broilers.