Effects of Thermostable Phytase Supplementation on the Growth Performance and Nutrient Digestibility of Broilers

A study was conducted to investigate the effects of thermostable phytase supplementation on the growth performance and nutrient digestibility of broilers for 42 d. 1-day-old Arbor Acres chicks with similar initial body weight were randomly divided into 3 treatments consisting 6 pens of 20 chicks per pen. The control group was given maize-soybean meal basal diet and the other two groups were fed the basal diet including either 500 U ordinary phytase/kg diet or 500 U thermostable phytase/kg diet. The results indicated that broilers given diets supplemented with thermostable phytase have increased body weight, body weight gain and feed intake than these fed basal diet (p<0.05). However, the same effect was only noted for body weight in ordinary phytase-supplemented group (p<0.05). Birds fed diet supplemented with thermostable phytase had enhanced crude protein utilization when compared with these given basal diet (p<0.05) but the same effect was not observed for broilers fed ordinary phytase-supplemented diet. As expected, dietary phytase supplementation significantly enhanced nitrogen-corrected apparent metabolizable energy of broilers (p<0.05) and this effect was more pronounced in the thermostable phytase-supplemented group. The results suggested that phytase supplementation, especially thermostable phytase supplementation, can improve the growth performance and nutrient utilization of broilers.