本试验旨在研究低磷饲粮中添加不同水平植酸酶对五龙鹅生长性能、养分表观利用率及粪中大肠杆菌数量和总氮、总磷含量的影响。选择1日龄五龙鹅216只,随机分为6个组,每组3个重复,每个重复12只鹅。Ⅰ组为正对照组,饲喂基础饲粮(未添加植酸酶);Ⅱ组为负对照组,饲喂降低0.1%有效磷水平的低磷饲粮(未添加植酸酶);Ⅲ～Ⅵ组分别饲喂在低磷饲粮基础上添加300、600、900、1 200 IU/kg植酸酶的试验饲粮。试验期16周。结果表明:1)1～4周龄,Ⅳ组平均日增重(ADG)和平均日采食量(ADFI)显著高于Ⅰ组(P<0.05),料重比(F/G)显著低于Ⅰ组(P<0.05),ADG极显著高于Ⅱ组(P<0.01),F/G极显著低于Ⅱ组(P<0.01);Ⅴ组ADG显著高于Ⅱ组(P<0.05),F/G显著低于Ⅱ组(P<0.05)。5～16周龄,Ⅳ、Ⅴ、Ⅵ组ADG和ADFI显著高于Ⅱ组(P<0.05),Ⅳ、Ⅴ组F/G显著低于Ⅱ组(P<0.05)。2)Ⅲ、Ⅳ、Ⅵ组钙、磷和酸性洗涤纤维表观利用率显著高于Ⅱ组(P<0.05);Ⅴ组钙、磷表观利用率极显著高于Ⅰ、Ⅱ组(P<0.01),中性洗涤纤维表观利用率显著高于Ⅰ、Ⅱ组(P<0.05);Ⅳ、Ⅴ组干物质表观利用率显著高于Ⅰ组(P<0.05)。3)Ⅲ、Ⅳ、Ⅴ、Ⅵ组粪中大肠杆菌数量显著低于Ⅱ组(P<0.05),Ⅳ、Ⅴ、Ⅵ组粪中总磷含量显著低于Ⅰ组(P<0.05)。由此可见,以生长性能作为衡量指标,1～4周龄五龙鹅饲粮植酸酶适宜添加水平为600 IU/kg,5～16周龄为900 IU/kg;以排泄物总磷含量为衡量指标,1～16周龄植酸酶适宜添加水平为900 IU/kg。

This experiment was conducted to study the effects of phytase on growth performance, nutrients apparent availability, the number of E.coli and the contents of total nitrogen and total phosphorus in fecal of Wulong geese. Two hundred and sixteen one-day-old Wulong geese were randomly divided into 6 groups with 3 replicates in each group and 12 geese in each replicate. Geese in the positive control group (group Ⅰ) were fed a basal diet (without phytase), geese in the negative control group (group Ⅱ) were fed a low phosphorus diet (without phytase, 0.1% lower available phosphorus), and the others in the experimental groups (groups Ⅲ～Ⅵ) were fed diets supplemented with 300, 600, 900, 1 200 IU/kg phytase in the low phosphorus diet, respectively. The experiment lasted for 16 weeks. The results showed as follows: 1) at 1 to 4 weeks of age, the average daily gain (ADG) and average daily feed intake (ADFI) in group Ⅳ were significantly higher than that in group Ⅰ (P<0.05), the feed to gain (F/G) in group Ⅳ was significantly lower than that in group Ⅰ (P<0.05), the ADG in group Ⅳ was significantly higher than that in group Ⅱ (P<0.01), and the F/G in group Ⅳ was significantly lower than that in group Ⅱ (P<0.01); the ADG in group Ⅴ was significantly higher than that in group Ⅱ (P<0.05), and the F/G in group Ⅴ was significantly lower than that in group Ⅱ (P<0.05). At 5 to 16 weeks of age, the ADG and ADFI in groups Ⅳ, Ⅴ, Ⅵ were significantly higher than that in group Ⅱ (P<0.05), and the F/G in groups Ⅳ, Ⅴ was significantly lower than that in group Ⅱ (P<0.05). 2) The apparent availability of calcium, phosphorus and acid detergent fiber in groups Ⅲ, Ⅳ, Ⅵ were significantly higher than that in group Ⅱ (P<0.05), the apparent availability of calcium and phosphorus in group Ⅴ were significantly higher than that in groups Ⅰ, Ⅱ (P<0.01), and the neutral detergent fiber apparent availability in group Ⅴ was significantly higher than that in groups Ⅰ, Ⅱ (P<0.05); the dry matter apparent availability in groups Ⅳ, Ⅴ was significantly higher than that in group Ⅰ (P<0.05). 3) The number of E.coli in groups Ⅲ, Ⅳ, Ⅴ, Ⅵ was significantly lower than that in group Ⅱ (P<0.05), and the total phosphorus content in groups Ⅳ, Ⅴ, Ⅵ was significantly lower than that in group Ⅰ (P<0.05). In conclusion, consideration from the growth performance, the optimal dietary phytase level is 600 IU/kg at 1 to 4 weeks of age, and 900 IU/kg at 5 to 16 weeks of age; while consideration from total phosphorus content in excretion, the optimal dietary phytase level is 900 IU/kg at 1 to 16 weeks of age.