Effect of physical feed form, phytase super dosing, and/or citric acid on growth performance, phosphorus digestibility, and intestinal microbial population of broiler chickens

Abstract

ABSTRACT We investigated the effects of feed form, phytase super dosing, and citric acid on growth performance, phosphorus digestibility, and intestinal microbial population of broiler chickens. For this purpose, 1000 newly hatched, straight-run Cobb 500 broiler chicks were assigned to 8 experimental treatments with five replicate pens each and 25 broiler chickens per replicate in a 2x2x2 factorial arrangement with two forms of feed (pellets or mash), two phytase concentrations (0 or 2000 FTU per kg), and two citric acid levels (0 or 0.4% of diet) for 42 days. Birds fed pelleted feed showed higher weight gain and feed intake than those fed mash form (p<0.05). Adding citric acid and phytase to the pelleted diets compared to the mash diets resulted in elevated body weight gain in chickens (p<0.05). Compared to the mash diets, the addition of phytase to the pelleted diet reduced the cecal aerobic bacterial population (p<0.05). The addition of both phytase and citric acid to the pelleted diets enhanced the phosphorus and calcium digestibility (P<0.05). In general, the use of pellet form with a mixture of citric acid and phytase was better than other treatments to improve performance and digestibility of phosphorus and calcium.

Keywords

• broiler chickens
• citric acid
• feed form
• phytase