Effect of citric acid and microbial phytase on small intestinal morphology in broiler chicken

An experiment was carried out to investigate the effects of citric acid (CA) (0, 3 and 6%) and microbial phytase (MP) (0, 500 and 1000 IU/kg) on morphology of different segments of small intestine (duodenum, jejunum and ileum) in broiler chickens fed on corn and soybean meal based diets. The effect of 9 experimental treatments (3×3 factorial design) were assessed using 270 7-d-old Ross 308 male broiler chicks in a randomized complete block design in three replicates of 10 birds each. The mean villi length (VL), crypt depth (CD) and goblet cell number (GCN) in duodenum, jejunum and ileum and villi width (VW) and VL:CD ratio in duodenum was significantly greater for the birds fed on acidified diets compared to the control birds at day 42 of age (P<0.01). Inclusion of 3% CA in diet significantly decreased the epithelial thickness (ET) in duodenum, jejunum and ileum (P<0.01). The birds received diets with 1000 IU/kg of MP showed significant increase in CD (P<0.01) and GCN in jejunum (P<0.05), and significant decrease in VL:CD ratio and ET in the duodenum (P<0.01), jejunum (P<0.05) and ileum (P<0.01) segments. No variable of interest were affected by CA × MP interaction. It was concluded that CA and MP independently exhibit positive impact on morphometery of small intestine, toward facilitating the nutrient absorption and reducing the metabolic demands of the intestinal tract in broiler chickens.