Variation in Phytate Phosphorus Utilization within the Same Broiler Strain

Abstract

This study evaluated the variation in ability to utilize phytate phosphorus among individual birds of the same strain of broilers. A 4-wk feeding trial was conducted with 100 day-old male broilers. Of these, 20 broilers were fed 0.5% available phosphorus (aP) and 0.95% Ca as the control and 80 broilers were fed a phosphorus-deficient diet containing 0.1% aP and 0.45% Ca. Livability, feed consumption, growth rate, and bone quality were the criteria used to test the effect of phytate P utilization. By the end of Week 2, some broilers fed 0.1% aP shoed lower feed consumption, severely reduced growth, and leg problems as a sign of sever P-deficiency, whereas some other birds showed normal growth, no leg weakness, and no visual signs of P-deficiency. Phytate P analysis of manure collected at the end of Weeks 2 and 4 revealed that broilers that showed normal growth (identified as “larger” birds) within the P-deficient group, utilized significantly more phytate P than the birds with stunted growth (identified as “smaller” birds). Bone analysis also showed that the larger birds had stronger bones than the smaller birds. Broilers fed P-deficient diets utilized significantly more phytate P than those fed diets containing 0.5% aP. Results suggest that the variation in individual bird's ability to respond to a phosphorus deficiency was related to variation in ability to utilize phytate P.