Danisco Animal Nutrition, IFF, Willem Einthovenstraat 4, 2342 BH Oegstgeest, the Netherlands.
Monogastric Research Centre, School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand.
Poult Sci. 2022 Mar;101(3):101666. doi: 10.1016/j.psj.2021.101666. Epub 2021 Dec 23.
Data from 13 datasets from 4 trials on the effect of a novel consensus bacterial 6-phytase variant (PhyG) on the apparent ileal digestibility (AID) of amino acids (AA) in broilers were used to model AID AA responses. The datasets were obtained from 3 trial locations (New Zealand, Australia and United States) and collectively incorporated variations in diet composition (feedstuff composition, phytate-P (PP) level, limestone solubility), feed form (mash or pellet), bird genetics (strain), and age at sampling (11-35 d of age). In total, 384 observations were analyzed. First, the relationships between AID of AA (as coefficients) and increasing phytase dose level from 0 to 4,000 FTU/kg were evaluated across all datasets using exponential curve fitting. Second, the percentage unit change in AID of AA at each phytase dose level from baseline (basal diet [BD] without phytase) was calculated separately for each dataset and the data then modeled together using exponential curve fitting. The model-predicted mean coefficient of AID of total AA in basal diets was 0.76 (range 0.56 [Cys] to 0.83 [Glu]), which was increased by PhyG to 0.80 and 0.81 at 2,000 and 4,000 FTU/kg, respectively. Exponential increases in the percentage unit improvement in AID of 18 individual and of total AA with increasing phytase dose level were evident (P < 0.05). Improvements (vs. BD) at 2,000 FTU/kg and 4,000 FTU/kg, respectively, were greatest for Cys (+9.2 and +11.0% units), Met (after deduction of synthetic Met, +8.4 and +9.0% units), and Thr (after deduction of synthetic Thr, +6.2 and +7.3% units). The data demonstrated consistent improvements in the AID of AA by the phytase. The modeling results generated from data gathered from birds sampled at different ages and from different dietary settings with correction of synthetic AA for Lys, Met, Thr, and Trp, enabled a more accurate prediction of the digestible AA contribution from the diet by this novel phytase. This will allow diet-specific AA matrix recommendations to be made in commercial feed formulations.
使用来自 4 项关于新型共识细菌 6-植酸酶变体（PhyG）对肉鸡回肠氨基酸表观消化率（AID）影响的研究的 13 个数据集的数据来模拟 AID AA 反应。这些数据集来自 3 个试验地点（新西兰、澳大利亚和美国），综合考虑了饲料成分（饲料成分、植酸磷（PP）水平、石灰石溶解度）、饲料形式（糊料或颗粒料）、禽种（品系）和采样年龄（11-35 日龄）的变化。共分析了 384 个观测值。首先，使用指数曲线拟合评估了所有数据集在所有数据集上 AA 的 AID（作为系数）与植酸酶剂量水平从 0 到 4000 FTU/kg 的关系。其次，分别计算了每个数据集在每个植酸酶剂量水平下 AA 的 AID 单位百分比变化，然后使用指数曲线拟合对数据进行建模。模型预测基础日粮（无植酸酶）中总 AA 的 AID 平均系数为 0.76（范围为 0.56[Cys]至 0.83[Glu]），用 PhyG 分别提高到 0.80 和 0.81，在 2000 和 4000 FTU/kg 时。随着植酸酶剂量水平的增加，18 种和总 AA 的 AID 单位百分比的指数增加是明显的（P<0.05）。与基础日粮相比，2000 FTU/kg 和 4000 FTU/kg 时 Cys（+9.2 和+11.0%单位）、Met（扣除合成 Met 后，+8.4 和+9.0%单位）和 Thr（扣除合成 Thr 后，+6.2 和+7.3%单位）的改善最大。数据表明，植酸酶可显著提高 AA 的 AID。从不同年龄和不同日粮环境下的鸡采样中获得的数据，并对 Lys、Met、Thr 和 Trp 的合成 AA 进行了校正，为该新型植酸酶对日粮中可消化 AA 的贡献进行了更准确的预测。这将使特定于日粮的 AA 矩阵推荐能够在商业饲料配方中进行。
