The enzymatic digestibility of organic matter (EDOM) method is an in vitro multi-enzymatic method for estimating the organic matter (OM) digestibility of feeds. The EDOM method previously showed high accuracy with in vivo values for compound feeds. The aim of this study was to evaluate the precision of the EDOM method and determine its additivity, compared with the long-assumed additive property of the chemical components of compound feeds. 149 feed samples, 70 commercial compound feeds and 79 associated ingredients, were analyzed in a laboratory (lab1) for OM digestibility measured by EDOM (OMDEDOM) with 2 repetitions separated in time to estimate repeatability. Of the total samples, 49 compound feeds were further analyzed in a commercial laboratory (lab2) for OMDEDOM to determine reproducibility. The 49 compounds and their 69 associated ingredients were also analyzed by lab2 for dry matter (DM), ash, crude protein (CP), neutral detergent fiber (NDF), and starch. The EDOM method resulted in an intralaboratory correlation of 98.9% and an interlaboratory correlation of 92.6%, with no significant mean bias between the 2 laboratories tested. The formulation of compound feeds, total mixed rations, and mixtures in general assumes that their nutrient content can be calculated by adding together the nutrient supply of individual ingredients. This is of great importance in the feed industry for the creation of compound feeds. Additivity of OMDEDOM for the compound feed samples was evaluated by comparing the sum of the digestible OM (DOMEDOM) of the ingredients (predicted) with DOMEDOM estimated directly in the compound feed (observed). The regression of predicted versus observed showed a coefficient of determination (R2) of 0.93 and root mean square error (RMSE) of 1.07% of total DM, with no linear bias but with a mean bias (0.83% of DM). Additivity of CP, starch, crude fat, and NDF showed an R2 of 0.95, 0.98, 0.95, and 0.93, and RMSE of 1.56, 1.90, 0.39, and 1.46% of DM, respectively, all presenting linear bias. Crude fat also presented mean bias. Although significant, all linear and mean bias for DOMEDOM and chemical components were within the acceptable error limits for declaration of feeds. The results demonstrate the high precision of the EDOM method and its additive property, which is an advantage for the estimation of OM digestibility in compound feeds. Moreover, results of the tests of chemical components confirm their additive property.

中文翻译：

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通过体外多酶法获得的有机物消化率的精度和可加性。

有机物的酶消化率（EDOM）方法是一种体外多酶法，用于估算饲料的有机物（OM）消化率。先前的EDOM方法显示出具有高精度的复合饲料体内值。这项研究的目的是评估EDOM方法的精确度并确定其可加性，与长期以来假设的复合饲料化学成分的加性相比。在实验室（lab1）中分析了149种饲料样品，70种市售复合饲料和79种相关成分，并通过EDOM（OMDEDOM）测量了OM消化率，并及时进行了两次重复，以评估其重复性。在所有样品中，在商业实验室（lab2）中对49种配合饲料进行了OMDEDOM进一步分析，以确定其可重复性。Lab2还分析了49种化合物及其69种相关成分的干物质（DM），灰分，粗蛋白（CP），中性洗涤剂纤维（NDF）和淀粉。EDOM方法的实验室内相关性为98.9％，实验室间相关性为92.6％，在两个测试实验室之间没有显着的平均偏差。配合饲料，总混合日粮和混合物的配方通常假定其营养成分可以通过将各个成分的营养成分相加得出。这对于饲料工业中复合饲料的生产非常重要。OMDEDOM对配合饲料样品的可加性是通过比较成分（可预测的）的可消化OM（DOMEDOM）和直接在配合饲料中估算的DOMEDOM（观察到的）来评估的。预测值与观察值的回归表明，确定系数（R2）为0.93，均方根误差（RMSE）为总DM的1.07％，没有线性偏差，但有平均偏差（DM的0.83％）。CP，淀粉，粗脂肪和NDF的可加性分别显示R2为0.95、0.98、0.95和0.93，RMSE为DM的1.56、1.90、0.39和1.46％，均呈现线性偏差。粗脂肪也呈现出平均偏差。尽管显着，但DOMEDOM和化学成分的所有线性偏差和均值偏差均在进料声明的可接受误差范围内。结果表明，EDOM方法具有很高的精确度及其添加特性，这对于估算复合饲料中的OM消化率具有优势。此外，化学成分的测试结果证实了它们的加性。