Response of broilers to feeding low-calcium and total phosphorus wheat-soybean based diets plus phytase: Performance, digestibility, mineral retention and tibiotarsus mineralization

Abstract

A 42-d trial was conducted with broilers fed a wheat-soy bean-meal-based diet to compare three dietary levels of calcium (Ca) and total phosphorus (TP) plus phytase on growth performance parameters, nutrient digestibility, mineral retention and tibiotarsus bone parameters. Three treatments were compared: a high Ca and TP diet (H−; according to NRC recommendations) without addition of phytase; a moderate Ca and TP diet (M+) with 600 U kg-1 of phytase; and a low Ca and TP diet (L+; similar to local industry practices) with 600 U kg-1 of phytase supplementation. Feed intake and weight gain of broilers fed H− were not different to M+ or L+. Nutrients digestibility at 21 d was improved in animals fed M+ in comparison with H− and L+. Better phosphorus retention was observed for M+ at 21 d of age. The bone mineralization was similar for H− and M+ at 21 d of age, and for H−, M+ and L+ at 42 d of age.