Comparison of Wheat Bran Phytase and a Commercially Available Phytase on Turkey Tom Performance and Litter Phosphorus Content

摘要

This study evaluated the effects of wheat bran phytase or a commercially available phytase (Natuphos? 600) on growth performance and skeletal integrity of toms and forms of litter phosphorus. Five-wk-old Hybrid Converter toms were fed corn-soybean meal based mash diets for 12 wk in four 3-wk phases. Treatments consisted of 1) control [0.50, 0.44, 0.38 or 0.35% nonphytate phosphorus (nPP) at 5-8, 8-11, 11-14, or 14-17 wk of age, respectively]; 2) low phosphorus (0.1 percentage units less nPP and 0.2 percentage units less calcium than treatment 1); 3) calcium and nPP same as 2, but with 3.27% wheat bran in diet (900 units/kg phytase activity); 4) calcium and nPP same as 2, but with Natuphos?added to provide 900 units/kg from 5 to 11 wk or 600 units/kg from 11 to 17 wk. Body weight and feed intake were measured at the end of each phase and bone fracture force, strength and ash and litter phosphorus (total and soluble) were measured at 17 wk. Body weight was higher when toms were fed the control diet throughout the study compared to all other treatments and was not affected by phytase source. Tibia fracture force and ash were decreased by the low phosphorus diet but was similar for both phytase sources compared to the control diet. Litter soluble phosphorus content was higher in treatment 4 than treatment 2, but not treatment 1. Feeding wheat bran phytase yielded similar bird responses and litter soluble phosphorus as Natuphos? when fed to commercial toms.