Department of Poultry Science, Auburn University, Auburn, AL 36849, USA.
AB Vista, Marlborough, Wiltshire SN8 4AN, United Kingdom.
Poult Sci. 2021 Feb;100(2):964-972. doi: 10.1016/j.psj.2020.11.051. Epub 2020 Nov 30.
An experiment was conducted to evaluate effects of inositol and gradient phytase supplementation on growth performance and meat yield of broilers from 1 to 41 d of age. A total of 1,920 Yield Plus × Ross 708 male chicks were placed in 64 floor pens (30 birds per pen). Each pen received one of the 8 dietary treatments (8 replicate pens) from 1 to 15, 16 to 29, and 30 to 40 d of age. Treatment 1 was formulated to contain 0.165 and 0.150% lower calcium and phosphorus, respectively, than treatment 7 (positive control). Phytase was added to treatment 1 at concentration of 500, 1,500, 4,500, 13,500, and 40,500 phytase units (FTU)/kg to establish treatments 2 to 6, respectively. Treatment 8 was formulated by adding inositol to treatment 7 based on the expected inositol liberation in treatment 6. Feed and birds were weighed at 1, 15, 29, and 40 d of age to determine BW gain, feed intake, and feed conversion. Twelve birds per pen were processed at 41 d of age to determine carcass characteristics. From 1 to 40 d of age, log-quadratic effects of phytase (treatments 1-6) were observed for BW gain (P = 0.002) and feed conversion in broilers (P = 0.018), whereas feed intake increased log-linearly (P = 0.045). The addition of 40,500 FTU/kg of phytase increased cumulative BW gain (P = 0.001) and decreased cumulative feed conversion (P = 0.005) by 4.7 and 2.6%, respectively, compared with birds subjected to treatment 8. Log-quadratic effects of phytase additions were observed for carcass (P < 0.001) and breast meat weights (P = 0.004). Growth performance and carcass characteristics of broilers subjected to treatment 7 were similar (P > 0.05) to those of birds subjected to treatment 8. These data demonstrate that the extraphosphoric effects of phytase may be associated with increased feed intake of broilers. Inositol supplementation did not provide additional benefits to broilers in this study.
一项实验旨在评估肌醇和梯度植酸酶补充对 1 至 41 日龄肉鸡生长性能和肉质产量的影响。共有 1920 只 Yield Plus×Ross 708 雄性小鸡被安置在 64 个地板围栏中（每围栏 30 只鸡）。从 1 日龄至 15 日龄、16 日龄至 29 日龄和 30 日龄至 40 日龄，每个围栏接受 8 种饮食处理（8 个重复围栏）之一。处理 1 的钙和磷含量分别比处理 7（阳性对照）低 0.165%和 0.150%。在处理 1 中添加 500、1500、4500、13500 和 40500 植酸酶单位（FTU）/kg 的植酸酶，分别建立处理 2 至 6。处理 8 通过根据处理 6 中预期的肌醇释放来向处理 7 添加肌醇来配制。在 1、15、29 和 40 日龄时，每栏鸡称重以确定体重增加、饲料摄入量和饲料转化率。在 41 日龄时，每栏鸡的 12 只鸡被屠宰以确定屠体特性。从 1 日龄至 40 日龄，植酸酶（处理 1-6）的对数二次效应观察到肉鸡的体重增加（P=0.002）和饲料转化率（P=0.018），而饲料摄入量呈对数线性增加（P=0.045）。与接受处理 8 的鸡相比，添加 40500 FTU/kg 的植酸酶分别增加了 4.7%和 2.6%的累积体重增加（P=0.001）和降低了累积饲料转化率（P=0.005）。植酸酶添加的对数二次效应观察到屠体（P<0.001）和胸肉重量（P=0.004）。接受处理 7 的肉鸡的生长性能和屠体特性与接受处理 8 的肉鸡相似（P>0.05）。这些数据表明，植酸酶的额外磷效应可能与肉鸡饲料摄入量的增加有关。在本研究中，肌醇补充并没有给肉鸡带来额外的益处。
