Abstract The addition of phytase enzyme to broiler feed as a means of improving phosphorus (P) availability and reducing P excretion is widespread practice. New phytases with enhanced functionality continue to be developed. We tested the effects of a next generation biosynthetic bacterial 6-phytase on growth performance, tibia ash and P digestibility in broilers. Treatments included a nutritionally adequate positive control (PC) diet, a negative control (NC) diet formulated with reductions in Ca and available P (avP) of 2.0 g/kg and 1.9 g/kg (starter phase) and 2.0 g/kg and 1.8 g/kg (finisher phase), respectively, and three further diets comprising the NC supplemented with three levels of phytase (250, 500 or 1000 FTU/kg). Diets were fed in mash form to day-old Cobb 500 broilers housed in pens (9 pens for NC, 10 pens for all other treatments; 24 birds/pen), in two phases (starter, days 1–21; finisher, days 22–42). Tibias were collected from 4 birds on day 21 and from 6 birds on day 42 for determination of defatted tibia ash. Ileal digesta was collected on day 21 for determination of apparent ileal digestibility (AID) of nutrients. Compared to PC, the NC exhibited reduced tibia ash at day 21 and 42, resulting in reduced average daily gain (ADG) and average daily feed intake (ADFI) during starter, finisher, and overall phases, and increased feed conversion ratio (FCR) during finisher phase and overall (P

中文翻译：

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下一代生物合成细菌 6-植酸酶在提高以玉米-豆粕为基础日粮的肉鸡的磷利用率方面的功能

摘要 在肉鸡饲料中添加植酸酶作为提高磷（P）利用率和减少磷排泄的一种手段是普遍的做法。不断开发具有增强功能的新植酸酶。我们测试了下一代生物合成细菌 6-植酸酶对肉鸡生长性能、胫骨灰分和磷消化率的影响。治疗包括营养充足的阳性对照 (PC) 饮食、阴性对照 (NC) 饮食，其中 Ca 和可用 P (avP) 减少 2.0 g/kg 和 1.9 g/kg（起始阶段）和 2.0 g/kg，以及分别为 1.8 g/kg（肥育阶段），以及包含 NC 并补充了三种水平的植酸酶（250、500 或 1000 FTU/kg）的另外三种饮食。日粮以饲料的形式喂给圈养在鸡舍中的日龄 Cobb 500 肉鸡（9 圈用于 NC，10 圈用于所有其他处理；24 羽/围栏），分两个阶段（首发，第 1-21 天；完赛，第 22-42 天）。在第 21 天从 4 只鸡和第 42 天从 6 只鸡收集胫骨，用于测定脱脂胫骨灰分。在第 21 天收集回肠食糜，用于测定营养物质的表观回肠消化率 (AID)。与 PC 相比，NC 在第 21 天和第 42 天表现出减少的胫骨灰分，导致在开始、育肥和整个阶段的平均日增重 (ADG) 和平均日采食量 (ADFI) 降低，并提高饲料转化率 (FCR)在完成阶段和整体（P