The effect of phytase and calcium (Ca) was investigated on performance of broiler chickens given diets severely limited in nonphytate phosphorus (NPP). A total of 550 ten-day-old broiler chickens were allocated to 10 diets from 11 to 40 d of age. There were a positive control (with adequate Ca and NPP concentration) and 9 diets (with 1.4 g NPP/kg) consisting of Ca (5.6, 4.2, and 2.8 g/kg) and phytase (0, 1,500, and 3,000 FTU/kg) in a 3 × 3 factorial arrangement of treatments with 5 pens per treatment. Increasing phytase dose linearly increased BW (P < 0.001) and tibia ash (P < 0.001) and reduced feed-to-gain ratio (F:G, P < 0.001) and mortality (P < 0.05). Increasing phytase dose quadratically affected tarsometatarsus strength (P < 0.001) and tibia ash percentage (P < 0.05). Decreasing Ca concentration linearly increased BW (P < 0.001) and reduced F:G (P < 0.001), mortality (P < 0.01), and tibia ash (P < 0.05). In terms of BW (P < 0.05), F:G (P < 0.01), mortality (P < 0.05), tibia ash (P < 0.05), and tarsometatarsus strength (P < 0.01), response to phytase addition was greater for high Ca concentrations, resulting in a Ca × phytase interaction. Generally, increasing phytase dose or decreasing Ca concentration in severely low NPP diet has beneficial effect on BW, F:G, and mortality of broiler chicken. If performed in combination, performance results improve even more. Nonetheless, when phytase is supplemented in the diet, decreasing Ca concentration does not allow maximum bone strength and ash.

在严格限制非植酸磷（NPP）的日粮中，研究了肌醇六磷酸酶和钙（Ca）对肉鸡生产性能的影响。总共550只10日龄的肉鸡被分配给11至40天龄的10种日粮。有一个阳性对照（具有适当的Ca和NPP浓度）和9种饮食（NPP为1.4 g / kg），其中Ca（5.6、4.2和2.8 g / kg）和植酸酶（0、1,500和3,000 FTU / kg）组成）以3×3阶乘的方式排列，每次处理5支。肌醇六磷酸酶剂量的增加线性增加体重（P  <0.001）和胫骨灰分（P  <0.001）并降低饲料增重比（F：G，P  <0.001）和死亡率（P <0.05）。肌醇六磷酸酶剂量的增加对酒石some强度（P  <0.001）和胫骨灰分百分率（P  <0.05）产生了方形影响。降低Ca浓度线性增加BW（P  <0.001）和降低F：G（P  <0.001），死亡率（P  <0.01）和胫骨灰分（P  <0.05）。体重（P  <0.05），F：G（P  <0.01），死亡率（P  <0.05），胫骨灰分（P  <0.05）和some骨强度（P <0.01），高钙浓度对植酸酶添加的响应更大，导致钙×植酸酶相互作用。通常，在极低的NPP饮食中增加肌醇六磷酸酶剂量或降低Ca浓度对肉鸡的BW，F：G和死亡率具有有益的影响。如果结合执行，性能结果将进一步提高。但是，在饮食中添加肌醇六磷酸酶时，降低钙的浓度并不能使骨骼强度和灰分最大化。