Performance and bone quality of broiler chicken fed diet with low level of nonphytate phosphorus with bacterial phytases

This study evaluated the effect of three phytases in reduced nonphytate phosphorus (NPP) diets. In total, 2100 male Cobb 500 (R) chicks were distributed in a completely randomized design. Ten experimental diets were used: NPP1 reduction of 0.12% NPP plus phytase A, B, C, or without; NPP2 reduction of 0.22% NPP plus phytase A, B, C, or without; positive control diet, attending nutrient requirements; negative control diet, deficit of 0.10% NPP. The 2 x 4 + 2 (two levels NPP, three phytases or without, and two controls) design was used, and the means were compared by Tukey's or Dunnet's (p < 0.05) tests. There were significant interactions on day 21 for weight gain (p < 0.01), feed conversion ratio (p < 0.01), and day 35 for weight gain (p < 0.01), feed intake (p < 0.01), feed conversion ratio (p < 0.01), European production efficiency factor (p < 0.01), and it was shown that three phytases in NPP1 diet had the same result as positive control (PC) diet. NPP2 diets without phytase promoted high calcium (p < 0.01) and low phosphorus (p < 0.01) in plasma, and the significant interaction showed higher activity for alkaline phosphatase (p = 0.023). The significant interactions for resistance (p = 0.001) and ash (p < 0.01) of femur indicate that inclusion of phytases in diet NPP1 improved the availability of minerals, suggesting that this reduction plus phytase would be enough for better results.