Effects of Dietary Garlic (Allium sativum Linn.) Supplementation on Body Weight and Gut Morphometry of Commercial Broilers

The effect of garlic on the absorptive surface of the small intestine of broilers was investigated towards elucidating its mechanism of growth promotion. One hundred day-old Arbor acre broilers were reared in 4 separate groups of twenty-five each. Broiler diet was supplemented with graded doses of garlic meal viz: 0% - group A; 0.125% - group B; 0.25% - group C; 0.5% - group D. Feed conversion ratio (FCR) was determined at 6 week-old. At 8 week-old, five broilers/group were selected randomly, euthanized and sections of the jejunum were harvested for histological examination. Villi lengths, widths and cryptal depths were determined. Mean body weight at 8 weeks old was highest in group B (1930 +/- 41g) and least in group A (1850 +/- 92g). FCR was highest in group D (4.34) and least in group B (3.8). Mean villi length, villi width and cryptal depth were highest (p<0.05) in group B i.e. 39.3 +/- 2.3 mm, 7.64 +/- 1.6 mm and 23.0 +/- 1.6 mm, respectively, indicating increased absorptive surface area. It was concluded that garlic meal supplementation at 0.125% in the diet of commercial broilers improved body weight gain and FCR by increasing villi length, villi width and cryptal depth.