Effect of dietary garlic meal on histological structure of small intestine in broiler chickens

This study was conducted to evaluate the effect of garlic (Allium sativum) meal on the intestinal mucosal morphology of broiler chickens between 21 and 42 days of age. A total of 1800, 21 days old Ross 308 broiler chicks were weighed and randomly allotted into 0, 0.125, 0.25, 0.5, 1 and 2% dietary garlic meal groups of each 100 birds. Experimental diets were formulated by addition of each level of garlic meal to commercial finisher mash diet (CP: 20.45%, ME: 3,130kcal/kg), and fed ad libitum for 21 d. At day 42, 15 chicks from each treatment were randomly killed to obtain intestinal samples. Villus height, epithelial thickness, goblet cell numbers, crypt depth and the ratio of crypt depth to villus height in each intestinal segment were compared using a light microscope. Garlic meal as a feed additive significantly enhanced villus height and crypt depth and decreased epithelial thickness and goblet cell numbers in duodenum, jejunum and ileum of birds. Fundamentally, jejunum and ileum revealed an almost similar morphological alteration to that in the duodenum except that dietary garlic meal supplement resulted in an increase in the ratio of crypt depth to villus height in duodenum but a decrease in jejunum and ileum. In present study, small intestinal morphological changes in chickens due to dietary garlic meal supplement demonstrate that absorptive process could be activated by garlic meal as an antibiotics alternative growth promoter.