Matrix values for exogenous enzymes and their application in the real world
Matrix values for exogenous enzymes and their application in the real world
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DOI：
10.1016/j.japr.2019.10.011
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发表时间：
2020-03-01
影响因子：
1.9
通讯作者：
Cowieson, A. J.
中科院分区：
文献类型：
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作者：
Bedfordand, M. R.;Cowieson, A. J.
在商业实践中酶的使用通常与营养基质的应用相关，以达到预期的效果。此类基质通过多种不同方法确定，并且在许多情况下采用消化率和/或性能试验。每种方法都有其局限性，但如果单独使用消化率试验，则必须特别小心，因为它们忽略了摄入和吸收后的影响。此外，对饲料酶的反应在很大程度上取决于多种环境、饮食和畜牧业相关因素，因此，商业营养师应考虑用于生成基质的测定条件与使用酶的条件之间的差异。在其应用中，如果成分限制（例如最低脂肪浓度）阻止了昂贵、营养丰富的成分的减少，则分配给酶的营养基质可能不一定会按预期降低成本。此外，大多数酶都是以固定剂量配制的，但这限制了它们的价值，因为大多数酶倾向于以对数剂量释放营养物质：线性营养物质释放关系。存在考虑这种影响的方法，并且能够真正以最低成本配制酶作为成分。最后，例如，商业口粮通常可以使用3种酶，每种酶都具有相关的能量基质。尽管它们传递该值的机制可能不同，但在实际应用之前，应谨慎确保它们的基质真正具有相加性。
The use of enzymes in commercial practice is most often associated with the application of a nutrient matrix to account for the expected effects. Such matrices are determined by a number of different methods and in many cases digestibility and/or performance trials are employed. Each has its limitations, but particular care must be taken if digestibility trials are used in isolation as they ignore intake and postabsorptive effects. Moreover, the response to a feed enzyme is very much dependent upon a multitude of environmental, dietary, and husbandry-related factors, and as a consequence, the commercial nutritionist should take into consideration the divergence between the conditions of the assay used to generate a matrix and the conditions under which the enzyme will be employed. In their application, nutrient matrices assigned to enzymes may not necessarily reduce costs as expected if ingredient constraints (e.g. min fat concentration) prevent reductions in expensive, nutrient rich ingredients. Furthermore, most enzymes are formulated in at a fixed dose, but this limits their value as the majority tend to release nutrients in a log dose: linear nutrient release relationship. Methods to take such an effect into account exist and enable true least cost formulation of the enzyme as an ingredient. Finally, often a commercial ration may employ 3 enzymes, each of which has an associated energy matrix, for example. Even though the mechanisms through which they deliver this value may be different, it is prudent to ensure that their matrices are truly additive before application in the field.