本研究旨在探讨2种剂型(粉状和颗粒状)植酸酶对产蛋高峰期蛋鸡产蛋性能、蛋品质和骨骼质量的影响。选取1 440只30周龄产蛋高峰期罗曼粉壳蛋鸡随机分为4个处理，每个处理10个重复，每个重复36只。处理Ⅰ为正对照组，饲喂基础饲粮，处理Ⅱ为负对照组，在试验期的第1～5周在正对照组饲粮的基础上分别降低钙和有效磷水平至3.23%和0.24%，而在试验期的第6～10周则降至3.23%和0.19%，处理Ⅲ在处理Ⅱ的基础上添加粉状植酸酶（300 U/kg），处理Ⅳ在处理Ⅱ的基础上添加颗粒状植酸酶（300 U/kg）。试验期10周。结果表明，低磷饲粮显著降低全期平均日采食量和胫骨灰分含量(P<0.05)，提高后期破蛋率(P<0.05)，对日产蛋率、平均蛋重、蛋品质等无显著影响(P>0.05)。添加2种植酸酶均显著提高平均日采食量(P<0.05)和胫骨灰分含量(P<0.01)，但2种植酸酶之间产蛋率、平均蛋重、蛋品质等无显著差异(P>0.05)。添加粉状植酸酶能显著提高灰分中磷的含量(P<0.05)，添加颗粒状植酸酶显著降低了后期破蛋率(P<0.05)。由此可知，在低磷蛋鸡饲粮中添加植酸酶可显著提高蛋鸡平均日采食量和胫骨灰分含量，对蛋品质的影响不显著。2种剂型的植酸酶对产蛋性能、蛋品质和骨骼质量的影响无显著差异。

This experiment was conducted to study the effects of two different dosage forms of phytase (powdery and granular) on laying performance, egg quality and bone quality of laying hens. A total of 1 440 30-week-old Lohmann pink-shell hens were randomly assigned to 4 treatments with 6 replicates each and 18 hens in each replicate. Treatment Ⅰ was the positive control group (PC); treatment Ⅱ was the negative control group (NC) for which diet was formulated on the basis of PC diet with Ca and AP levels decreased to 3.23% and 0.24% (1 to 5 weeks) or 3.23% and 0.19% (6 to 10 weeks), respectively; diets for treatments Ⅲ and Ⅳ were supplemented with powdery or granular phytase based on NC diet (300 U/kg). The experiment lasted for 10 weeks. The results showed that feed intake and bone ash were significantly decreased (P<0.05), while egg broken ratio (6 to 10 weeks) was significantly increased (P<0.05) in NC group, but there were no significant differences in egg production, egg weight and egg quality of laying hens in NC group (P>0.05), and there were no significant differences in laying rate, egg quality, and average egg weight between powdery and granular phytase (P>0.05). Dietary supplementation with powdery phytase could significantly increase the phosphorous content of bone ash (P<0.05), and dietary supplementation with granular phytase could significantly decrease the cracked and broken egg ratios in 6 to 10 weeks (P<0.05). In conclusion, dietary supplementation with phytase in low phosphor diet can improve average daily feed intake and bone ash of laying hens without damaging egg quality. There is no difference in laying performance, egg quality and bone quality between powdery and granular phytase. ［Chinese Journal of Animal Nutrition, 2010，22（5）:1374-1381］