Effects of phytase on utilization of nutrients and performance of growing pigs

144 growing pigs(Duroc×Landrace×Yorkshire) were conducted to study the effects of two kinds of phytase using as substitute for partial inorganic phosphorus in diet on the growth performance,nutrient availability,serum biochemical parameters and excretion of feces P and N.There were 3 treatments:control group,experiment group Ⅰ,experiment groupⅡ,normal diet was fed to control group,low-P diet with the addition of phytaseⅠwas fed to experiment groupⅠ,low-P diet with the addition of phytase Ⅱwas fed to experiment groupⅡ.Each treatment had 4 replicates with 12 pigs per pen.The addition of phytase to low-P diet improved ADG(P0.05),reduced F/G(P0.05).Adding phytase to low-P diet improved the apparent digestibility of DM,CP,CF,EE,Ca,P,GE respectively but decreased the excretion of feces P and feces N(P0.05);The enzymatic activity of alkaline phosphatase in serum and the concentration of albumin,and P were not affected by adding phytase(P0.05),but the concentration total protein of in serum,globulin and Ca were improved by adding phytase(P0.05) to diets,the concentration of BUN was decreased by adding phytase(P0.05)to diets,the concentration of BUN was decreased by adding phytase(P0.05)to diets.And there was on big difference between the effect of phytaseⅠand phytaseⅡon growing pig production.