Effect of Phytase on the Growth Performance, Calcium and Phosphorus Availability of Broilers

This study was carried out to determine the effects of phytase on the growth performance, bone mineralization, digestion and metabolization of nutrientsubstance in Avian broilers. Each of 400, 1 day old male Avian broilers and 400, 1 day old female Avian broilers was randomly divided into 5 groups (Group I, available phosphorus-adequate group without phytase; Group II, available phosphorus-deficient group without phytase; Group III, available phosphorus-deficient group with 250 U kg(-1) phytase; Group IV, available phosphorus-deficient group with 500 U kg(-1) phytase; Group V, available phosphorus-deficient group with 750 U kg(-1) phytase). Each group included 4 replicates, each with 20 broilers. The results showed that the effect of phytase on the growth permance in male broilers was more obvious than that of female. Dry tibia weights of male and female broilers fed with Group II and III diets were decreased compared with Group I; Group IV and V were increased compared with Group I. Tibia phosphorus contents of male and female broilers fed with Group IT-V were decreased compared with Group I. Tibia calcium contents of male broilers fed with Group II and V diets were increased by compared with Group I; Group III and IV were decreased compared with Group I. Tibia calcium contents of female broilers fed with Group II, IV and V diets were increased compared with Group I; Group III was decreased compared with Group I. Apparent digestibility coefficients of total phosphorus of Group II-V in male and female broilers were increased compared with Group I. Phosphorus concentrations of faeces of Group II-V in male and female broilers were decreased compared with Group I. Apparent digestibility coefficients of calcium Group II-V in male and female broilers were increased compared with Group I. The result showed that phytase added to available phosphorus-deficient broiler diet could improve the growth performance, bone mineralization as well as calcium and phosphorus availability.