Effects of phytase supplementation on bone development and growth in broilers fed nutritionally adequate and calcium, phosphorus, and sodium deficient diets

Abstract

This study evaluated the effects of phytase supplementation on bone quality in broiler chickens fed corn-, soybean meal-, and soybean oil-based diets deficient in phosphorus (P), calcium (Ca) and sodium (Na). A total of 1,548 male broiler chicks were assigned to a completely randomized design comprising four dietary treatments, nine replicates per treatment, and 43 birds per replicate. Treatments consisted of a positive control (PC) formulated to meet recommended nutrient requirements, a negative control (NC) diet with reductions of 0.15% phosphorus, 0.16% calcium, and 0.03% sodium, and the NC diet supplemented with either 500 or 10000 FTU kg-1 phytase. Phytase supplementation significantly improved (p < 0.05) tibial bone mineral density at 21 and 47 days compared with the unsupplemented NC diet. At 21 days, broilers fed the NC diet exhibited the lowest (p < 0.05) bone-to-cartilage ratio. Phytase supplementation also increased (p<0.05) bone breaking strength throughout the experimental period, restoring values comparable to those observed in birds fed the nutritionally adequate diet. Supplementation with 10000 FTU kg-1 phytase reduced femoral bone elasticity at 21 and 47 days while increasing femur length at 7 and 21 days relative to the NC treatment. Overall, phytase supplementation effectively restored bone development in broilers fed diets deficient in P, Ca, and Na.