Nuamah Emmanuel, Okon Utibe Mfon, Jeong Eungyeong, Mun Yejin, Cheon Inhyeok, Chae Byungho, Odoi Frederick Nii Ako, Kim Dong-Wook, Choi Nag-Jin
Department of Animal Science, Jeonbuk National University, Jeonju 54896, Republic of Korea.
Department of Animal Science, Faculty of Agriculture, Akwa Ibom State University, Mkpat Enin 532111, Nigeria.
Animals (Basel). 2024 Jul 17;14(14):2090. doi: 10.3390/ani14142090.
The inclusion of exogenous phytase in P- and Ca-deficient diets of broilers to address the growing concern about excessive P excretion into the environment over the years has been remarkably documented. However, responses among these studies have been inconsistent because of the several factors affecting P utilization. For this reason, a systematic review with a meta-analysis of results from forty-one studies published from 2000 to February 2024 was evaluated to achieve the following: (1) quantitatively summarize the size of phytase effect on growth performance, bone strength and mineralization in broilers fed diets deficient in P and Ca and (2) estimate and explore the heterogeneity in the effect size of outcomes using subgroup and meta-regression analyses. The quality of the included studies was assessed using the Cochrane Collaboration's SYRCLE risk of bias checklists for animal studies. Applying the random effects models, Hedges' g effect size of supplemented phytase was calculated using the R software (version 4.3.3, Angel Food Cake) to determine the standardized mean difference (SMD) at a 95% confidence interval. Subgroup analysis and meta-regression were used to further explore the effect size heterogeneity ( ≤ 0.05, > 50%, n ≥ 10). The meta-analysis showed that supplemental phytase increases ADFI and BWG and improves FCR at each time point of growth ( < 0.0001). Additionally, phytase supplementation consistently increased tibia ash, P and Ca, and bone strength ( < 0.0001) of broilers fed P- and Ca-deficient diets. The results of the subgroup and meta-regression analyses showed that the age and strain of broiler, dietary P source, and the duration of phytase exposure significantly influence the effect size of phytase on growth and bone parameters. In conclusion, phytase can attenuate the effect of reducing dietary-available phosphorus and calcium and improve ADFI, BWG, and FCR, especially when added to starter diets. It further enhances bone ash, bone mineralization, and the bone-breaking strength of broilers, even though the effects of bone ash and strength can be maximized in the starter phase of growth. However, the effect sizes of phytase were related to the age and strain of the broiler, dietary P source, and the duration of phytase exposure rather than the dosage.
多年来，为应对人们对肉鸡向环境中过度排泄磷的日益担忧，在缺磷和缺钙的肉鸡日粮中添加外源植酸酶的做法已有大量文献记载。然而，由于影响磷利用率的因素众多，这些研究的结果并不一致。因此，对2000年至2024年2月发表的41项研究结果进行了系统综述和荟萃分析，以实现以下目标：(1) 定量总结植酸酶对饲喂缺磷和缺钙日粮的肉鸡生长性能、骨强度和矿化的影响大小；(2) 使用亚组分析和荟萃回归分析估计并探索结果效应大小的异质性。使用Cochrane协作网动物研究偏倚风险检查表对纳入研究的质量进行评估。应用随机效应模型，使用R软件（版本4.3.3，天使食品蛋糕）计算补充植酸酶的Hedges' g效应大小，以确定95%置信区间的标准化平均差（SMD）。亚组分析和荟萃回归用于进一步探索效应大小的异质性（P≤0.05，I²>50%，n≥10）。荟萃分析表明，补充植酸酶可增加平均日采食量（ADFI）和平均日增重（BWG），并在生长的每个时间点改善饲料转化率（FCR）（P<0.0001）。此外，补充植酸酶可使饲喂缺磷和缺钙日粮的肉鸡胫骨灰分、磷和钙以及骨强度持续增加（P<0.0001）。亚组分析和荟萃回归结果表明，肉鸡的年龄和品系、日粮磷源以及植酸酶暴露持续时间显著影响植酸酶对生长和骨骼参数的效应大小。总之，植酸酶可以减轻日粮中可利用磷和钙减少的影响，提高ADFI、BWG和FCR，尤其是添加到雏鸡日粮中时。它还能增强肉鸡的骨灰分、骨矿化和骨折强度，尽管骨灰分和强度的影响在生长的起始阶段可达到最大。然而，植酸酶的效应大小与肉鸡的年龄和品系、日粮磷源以及植酸酶暴露持续时间有关，而与剂量无关。
