Velayudhan Deepak, Dersjant-Li Yueming, Lizardo Rosil, Kumar Arun, Stein Hans H, Espinosa Charmaine D, Cantarelli Vinicius, Hardy Rachael, Vinyeta Ester, Marchal Leon
Danisco Animal Nutrition & Health (IFF), Willem Einthovenstraat 4, 2342 BH Oegstgeest, The Netherlands.
Institut de Recerca I Tecnologia Agroalimentàries, Centre Mas de Bover, Ctra. Reus-El Morell km. 3.8, E-43120, Constantí, Spain.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf245.
Data from 8 datasets generated from 5 independent experiments that determined the effects of a consensus bacterial 6-phytase variant (PhyG) on apparent ileal digestibility (AID) of amino acids (AA) in growing pigs (~21 to 45 kg body weight) were combined and modeled to test the hypothesis that the phytase results in significant improvements in ileal AA digestibility. The aim was to generate accurate and robust dose-related predictions of the digestible AA contributions of the phytase. The 5 experiments were conducted in Spain, Australia, USA, and Brazil and incorporated variation in diet composition (ingredient composition, phytate-phosphorus (PP) content, limestone solubility), diet form, animal breed and sex. A total of 325 datapoints (observations) were analyzed. First, the relationship between the percentage AID of AA and log-transformed phytase dose (range 0 to 4,000 phytase units (FTU)/kg, analyzed values) was modeled by log-linear regression across all datasets without adjustment for variation in the response to the negative control (NC) diet. The model predicted that the mean AID of total AA in the NC diets was 68.6% (range 43.3% [Cys] to 81.7% [Arg]). This was increased linearly by PhyG supplementation (P < 0.05), by 3.7 percentage units when dosed at 1,000 FTU/kg and by 4.5 percentage units at 4,000 FTU/kg. Second, the percentage unit change in the AID of AA at each phytase dose from baseline (NC without added phytase) was calculated separately for each dataset and the data then combined and modeled together by log-linear regression, against analyzed and log-transformed phytase dose. By this analysis, increases were evident for the AID of all individual (and total) AA. Increases (vs. baseline) at 1,000 and 2,000 FTU/kg were greatest for Trp (+ 6.1 and + 6.8 percentage units), Thr (+ 3.4 and + 3.8 percentage units after correction for synthetic Thr), Gly (+ 7.5 and + 8.3 percentage units) and Cys (+ 5.6 and + 6.2 percentage units). In conclusion, combined data from 5 separate experiments indicate that the bacterial phytase-6 variant will improve ileal digestibility of AA if included in diets fed to growing pigs. The data will allow diet-specific AA matrix recommendations to be made in commercial feed formulations containing PhyG.
合并了来自5个独立实验产生的8个数据集的数据，这些实验确定了一种共有细菌6-植酸酶变体（PhyG）对生长猪（体重约21至45千克）氨基酸（AA）的回肠表观消化率（AID）的影响，并进行建模以检验植酸酶能显著提高回肠氨基酸消化率这一假设。目的是生成关于植酸酶可消化氨基酸贡献的准确且可靠的剂量相关预测。这5个实验在西班牙、澳大利亚、美国和巴西进行，纳入了日粮组成（成分组成、植酸磷（PP）含量、石灰石溶解度）、日粮形式、动物品种和性别的变化。总共分析了325个数据点（观测值）。首先，在不针对阴性对照（NC）日粮反应的变化进行调整的情况下，通过对数线性回归对所有数据集建立了AA的AID百分比与对数转换后的植酸酶剂量（范围为0至4000植酸酶单位（FTU）/千克，分析值）之间的关系模型。该模型预测，NC日粮中总AA的平均AID为68.6%（范围为43.3%[半胱氨酸]至81.7%[精氨酸]）。添加PhyG后呈线性增加（P<0.05），剂量为1000 FTU/千克时增加3.7个百分点，4000 FTU/千克时增加4.5个百分点。其次，针对每个数据集分别计算了在每个植酸酶剂量下相对于基线（未添加植酸酶的NC）AA的AID的百分点变化，然后将数据合并并通过对数线性回归一起建模，以分析和对数转换后的植酸酶剂量为自变量。通过该分析，所有单个（及总）AA的AID均有明显增加。在1000和2000 FTU/千克时（相对于基线），色氨酸增加最多（分别增加6.1和6.8个百分点）、苏氨酸（校正合成苏氨酸后分别增加3.4和3.8个百分点）、甘氨酸（分别增加7.5和8.3个百分点）和半胱氨酸（分别增加5.6和6.2个百分点）。总之，来自5个独立实验的合并数据表明，如果将细菌植酸酶-6变体添加到生长猪日粮中，将提高AA的回肠消化率。这些数据将有助于在含有PhyG的商业饲料配方中做出特定日粮的AA矩阵推荐。
