Abstract: An experiment was conducted to investigate the effect of phytase,compound enzyme and probiotics supplemented in pig diets on the excretion of nitrogen and phosphorus in large scale pig farm. Fifteen Suzhong pig (60 kg) were randomly allocated to five treatments,control group (normal P level),negative control group (no CaHPO₄),negative control and phytase group,control and compound and phytase group,control and probiotics. The results showed that three diets decreased the excretion of nitrogen in manure and urine,the nitrogen excretion in phytase group decreased 0.55%(P＞0.05),compound and phytase group decreased 10%(P＜0.05),probiotics group decreased 6.11%(P＞0.05),and the reduction consequence of compound and phytase group was better than the others,the nitrogen excretion in urine was no significant differences(P＞0.05). Compared to the control group,the phosphorus excretion in manure of phytase group decreased 19.19%(P＞0.05),compound and phytase group decreased 36.63%(P＜0.05),probiotics group decreased 16.28%(P＞0.05),and the reduction consequence of compound and phytase group was better than the others,the phosphorus excretion in Urine of phytase group decreased 12%(P＞0.05),compound and phytase group decreased 16% (P＜0.05),probiotics group decreased 12%(P＞0.05),and the reduction consequence of compound and phytase group was better than the others. In conclusion,in the finishing pig diets supplemented with clean feeds decreased the environmental pollution caused by nitrogen and phosphorus excretion,and the reduction consequence of compound and phytase group was better.

Key words: large scale pig farm; clean feeds; nitrogen and phosphorus excretion; environmental pollution