Institute of Animal Science, University of Hohenheim, Stuttgart, Germany.
Arch Anim Nutr. 2020 Feb;74(1):1-18. doi: 10.1080/1745039X.2019.1687249. Epub 2019 Nov 26.
The objectives of this meta-analysis were to determine to which extent phosphorus (P) digestibility and digestible P concentration in pig diets were increased by phytase supplementation and to quantify factors that potentially influence effects of phytase supplementation. A data set with a total of 547 data lines was compiled from 88 experiments published in 74 peer-reviewed papers between 2007 and April 2019. An exponential model was determined as more suitable to describe the response of P digestibility to phytase supplementation than a polynomial model. Phytase supplementation increased P digestibility by 25.6 percentage points (standard error (SE) = 1.54) to a plateau at 64.9% (SE = 1.82). The digestible P concentration was increased by phytase supplementation in the order of 1.01 g/kg (SE = 0.102) to a plateau at 2.62 g/kg (SE = 0.122). Goodness-of-fit criteria were R = 0.780 and root mean square error = 7.55% for P digestibility, and R = 0.691 and root mean square error = 0.48 g/kg for digestible P concentration. Consideration of further factors such as mineral P supplementation (yes or no), vs. restrictive feeding, mixed diets vs. single feed ingredients, sex and age of pigs did not increase the accuracy of prediction in this data set. Some of these traits exhibited responses, but they likely are artefacts generated through the imbalanced structure of the data set. Effects of dietary total P, phytate (InsP), InsP-P to total P ratio, and Ca on the effect of supplemented phytase were not quantifiable. The present meta-analysis showed that responses to phytase supplementation can be well predicted although variation in P digestibility and digestible P concentration in the data set was high. Overall, predicted effects of phytase on P digestibility well corresponded to predictions made 25 years ago.
本荟萃分析的目的是确定植酸酶添加在多大程度上增加了猪日粮中磷（P）的消化率和可消化 P 浓度，并量化可能影响植酸酶添加效果的因素。本研究从 2007 年至 2019 年 4 月期间发表的 74 篇同行评议文献中的 88 个试验中汇总了总共 547 条数据线，建立了一个数据集。与多项式模型相比，指数模型更适合描述植酸酶添加对 P 消化率的响应。植酸酶添加将 P 消化率提高了 25.6 个百分点（标准误差（SE）= 1.54），达到 64.9%（SE = 1.82）的平台。植酸酶添加将可消化 P 浓度提高了 1.01 g/kg（SE = 0.102），达到 2.62 g/kg（SE = 0.122）的平台。P 消化率的拟合优度标准为 R = 0.780 和均方根误差 = 7.55%，可消化 P 浓度的拟合优度标准为 R = 0.691 和均方根误差 = 0.48 g/kg。考虑到其他因素，如矿物 P 添加（是或否）、限制饲养、混合日粮与单一饲料成分、猪的性别和年龄，并没有提高该数据集中的预测准确性。这些特征中的一些表现出了响应，但它们可能是由于数据集不平衡结构产生的人为产物。日粮总磷、植酸（InsP）、InsP-P 与总 P 之比以及 Ca 对添加植酸酶效果的影响无法量化。本荟萃分析表明，尽管数据集中 P 消化率和可消化 P 浓度的变异性较高，但可以很好地预测植酸酶的响应。总的来说，植酸酶对 P 消化率的预测效果与 25 年前的预测结果非常吻合。
