Effect Of Dietary Phosphorus Levels And Phosphorus Limitation On The Growth Performance Of Broiler Chickens Fed With Different Concentrations Of Phytase

In this experiment,the effects of different concentrations of phytase on the growth performance of broiler chickens(chickens)were studied by verifying the production value of high thermostability and high acid resistance phytase.The aim of this study was to investigate the bio-efficacy of heat-stable phytase with different available phosphorus(AP)level for broilers.A total of 800 broilers(Arbor Acres,d 0)were allotted into 8 treatments with 10 replicates(cages)per treatment.Treatment 1(T1)was formulated to contain0.45%available phosphorus(AP)in starter phase.T2,T3 and T4 treatments are formulated to be deficient in available phosphorus(AP),which contained 0.38%,0.31%and 0.24%available phosphorus(AP).T5 to T8 are formulated based on T4 and supplemented with three different levels(250,500,and 1000 U/kg)of phytase A and with 100 U/kg of phytase B.The duration was 18 days.Birds fed the diet had poorer weight,average daily feed intake(ADFI),and Feed conversion rate(FCR)compared with those fed the regular diet.Supplementation of the diet with phytase exhibited a linear trend to improve body weight(R~2=0.6241)and Feed conversion rate(R~2=0.9383).Birds fed phytase B diets had better growth performance than birds fed phytase A diets.Treatments contained 0.38%,0.31%and 0.24%available phosphorus(AP)showed liner trend to decrease the content of ash,Ca and P in tibia,and exhibited a linear trend to improve the content of ash,Ca and P in tibia with the supplementation of phytase.It can be concluded that phytase can improve the growth performance of broiler chickens fed a diet that is formulated to be suboptimal in terms of P.Phytase B was more effective in the improvement on the growth performance than phytase A.