Phytase has long been used to decrease the inorganic phosphorus (Pi) input in poultry diet. The current study was conducted to investigate the effects of Pi supplementation on laying performance, egg quality and phosphate–calcium metabolism in Hy-Line Brown laying hens fed phytase. Layers (n = 504, 29 weeks old) were randomly assigned to seven treatments with six replicates of 12 birds. The corn–soybean meal-based diet contained 0.12% non-phytate phosphorus (nPP), 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase. Inorganic phosphorus (in the form of mono-dicalcium phosphate) was added into the basal diet to construct seven experimental diets; the final dietary nPP levels were 0.12%, 0.17%, 0.22%, 0.27%, 0.32%, 0.37% and 0.42%. The feeding trial lasted 12 weeks (hens from 29 to 40 weeks of age). Laying performance (housed laying rate, egg weight, egg mass, daily feed intake and feed conversion ratio) was weekly calculated. Egg quality (egg shape index, shell strength, shell thickness, albumen height, yolk colour and Haugh units), serum parameters (calcium, phosphorus, parathyroid hormone, calcitonin and 1,25-dihydroxyvitamin D), tibia quality (breaking strength, and calcium, phosphorus and ash contents), intestinal gene expression (type IIb sodium-dependent phosphate cotransporter, NaPi-IIb) and phosphorus excretion were determined at the end of the trial. No differences were observed on laying performance, egg quality, serum parameters and tibia quality. Hens fed 0.17% nPP had increased (P < 0.01) duodenum NaPi-IIb expression compared to all other treatments. Phosphorus excretion linearly increased with an increase in dietary nPP (phosphorus excretion = 1.7916 × nPP + 0.2157; R2 = 0.9609, P = 0.001). In conclusion, corn–soybean meal-based diets containing 0.12% nPP, 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase would meet the requirements for egg production in Hy-Line Brown laying hens (29 to 40 weeks of age).

长期以来，植酸酶一直被用于减少家禽日粮中的无机磷 ( Pi ) 输入。目前的研究旨在调查添加磷对饲喂植酸酶的 Hy-Line Brown 蛋鸡的产蛋性能、蛋品质和磷酸盐-钙代谢的影响。层数（n = 504, 29 周龄）被随机分配到 7 个处理组，每组 12 只鸡重复 6 次。以玉米-豆粕为基础的日粮含有 0.12% 的非植酸磷 ( nPP )、3.8% 的钙、2415 IU/kg 维生素 D 3和 2000 FTU/kg 植酸酶。将无机磷（以磷酸一二钙的形式）添加到基础日粮中以构建七种实验日粮；最终日粮nPP水平分别为0.12%、0.17%、0.22%、0.27%、0.32%、0.37%和0.42%。饲养试验持续 12 周（母鸡 29 至 40 周龄）。每周计算产蛋性能（圈养产蛋率、蛋重、蛋重、每日采食量和饲料转化率）。蛋品质（蛋形指数、蛋壳强度、蛋壳厚度、蛋白高度、蛋黄颜色和 Haugh 单位）、血清参数（钙、磷、甲状旁腺激素、降钙素和 1,25-二羟基维生素 D）、胫骨质量（断裂强度和钙、磷和灰分含量），肠道基因表达（IIb 型钠依赖性磷酸协同转运蛋白，NaPi-IIb) 和磷排泄在试验结束时测定。在产蛋性能、鸡蛋质量、血清参数和胫骨质量方面没有观察到差异。与所有其他处理相比，饲喂 0.17% nPP 的母鸡十二指肠 NaPi-IIb 表达增加（P < 0.01）。磷排泄随着日粮 nPP 的增加而线性增加（磷排泄 = 1.7916 × nPP + 0.2157；R 2 = 0.9609，P = 0.001）。总之，含有 0.12% nPP、3.8% 钙、2415 IU/kg 维生素 D 3和 2000 FTU/kg 植酸酶的玉米豆粕型日粮可以满足 Hy-Line Brown 蛋鸡（29 至 40周龄）。