Jouany J P
I.N.R.A., Centre de Recherches de Clermont-Ferrand/Theix, France.
Arch Tierernahr. 1994;46(2):133-53. doi: 10.1080/17450399409381766.
Different methods of optimizing feed conversion into nutrients in the rumen are now available to scientists. But the rumen must be considered as an integrated system and this makes it difficult to rationalize manipulation. The observed result of any treatment is a combination of several interactive reactions. Any change to one component of the system has several uncontrolled effects on other components. The positive effects aimed for are sometimes associated with undesirable effects. Numerous chemical additives have been studied during the last two decades among which ionophore antibiotics represent the most important group. The interest of non-ionophore antibiotics, methane inhibitors, and compounds inhibiting proteases or deaminases, has also been considered during the last years. The observed effects of these chemical additives on animals, and their possible mode of action on rumen microbes and on animal metabolism, are discussed. However, the risks of the presence of residues in meat and milk are questioned by consumers. Microbial activity in the rumen can be altered by feeding animals with large amounts of certain food constituents (fats, starch) or minerals (buffer substances). The responses in the rumen to these dietary conditions are analyzed in terms of the digestive effects on plant cell wall degradation and microbial protein synthesis. Modification of the rumen microbial population is now considered as a possible approach to rumen manipulation by scientists. The effects on digestion of the elimination of ciliate protozoa (defaunation) are presented. The feasibility of these objectives, from a practical standpoint, is discussed. Finally, there is an overview of the effects of the addition of live yeasts (Saccharomyces cerevisciae), or fungi (Aspergillus orizae), used as probiotics. A possible mode of action of probiotics on the rumen ecosystem is suggested.
如今，科学家们可以采用不同方法来优化瘤胃中饲料向营养物质的转化。但瘤胃必须被视为一个综合系统，这使得对其进行合理调控变得困难。任何处理所观察到的结果都是多种相互作用反应的综合。系统中一个组成部分的任何变化都会对其他组成部分产生一些无法控制的影响。旨在实现的积极效果有时会伴随着不良影响。在过去二十年中，人们研究了众多化学添加剂，其中离子载体抗生素是最重要的一类。在过去几年里，非离子载体抗生素、甲烷抑制剂以及抑制蛋白酶或脱氨酶的化合物也受到了关注。本文讨论了这些化学添加剂对动物的观察效果及其对瘤胃微生物和动物代谢可能的作用方式。然而，消费者对肉类和牛奶中存在残留的风险提出了质疑。给动物喂食大量特定食物成分（脂肪、淀粉）或矿物质（缓冲物质）可改变瘤胃中的微生物活性。本文从对植物细胞壁降解和微生物蛋白质合成消化作用的角度分析了瘤胃对这些饮食条件的反应。现在科学家们认为改变瘤胃微生物群落是一种可能调控瘤胃的方法。文中介绍了消除纤毛虫原生动物（去原虫化）对消化的影响。从实际角度讨论了这些目标的可行性。最后，概述了添加用作益生菌的活酵母（酿酒酵母）或真菌（米曲霉）的效果。文中提出了益生菌对瘤胃生态系统可能的作用方式。
