This study aimed to study the effect of diet supplementation with probiotic, prebiotic and synbiotic on histology and intestinal of White Leghorn (WL) laying hens. A locally prepared probiotic were used each one gram of this probiotic contain at least 1010 Colony Forming Units of Bifidobacterium, L.acidophilus bacteria and 108(CFU) of Saccharomyces cerevisiae yeast and Aspergillus niger fungal respectivally. The prebiotic used in this study were consist a non starch oligosaccharide of S.cerevisiae yeast after crashing of cell wall .The synbiotic used in this study were prepared by mixed an equael amount from probiotic (Iraqi probiotic) and prebiotic. A total of 180 WL laying hens, 16 weeks old were randomly allocated into four treatment groups . Hens in T1 group were fed a standerd laying diet and used as control group. Hen in T2,T3 and T4 were fed diet supplemented with 5 Kg/ton of probiotic, prebiotic and synbiotic respectively. The experiment was conducted in poultry farm at Agriculture College– University of Baghdad for the period from 27th May 2005 to first of Jully 2006.
The data for the present study showed that feed supplementation with probiotic, prebiotic and synbiotic were significantly (P<0.01) increased villi length and cryps depth of the duodenum region as compared with the control group. The microbiological study data also revealed feed supplementation with probiotic, prebiotic and symbiotic were significantly (P<0.01) increased Lactobacilli and decresced Coliform bacteria count in crop, jujinum and cecum of laying hens.