Martin C, Morgavi D P, Doreau M
INRA, UR 1213, Herbivores Research Unit, Research Centre of Clermont-Ferrand-Theix, F-63122 St Genès Champanelle, France.
Animal. 2010 Mar;4(3):351-65. doi: 10.1017/S1751731109990620.
Decreasing enteric methane (CH4) emissions from ruminants without altering animal production is desirable both as a strategy to reduce global greenhouse gas (GHG) emissions and as a means of improving feed conversion efficiency. The aim of this paper is to provide an update on a selection of proved and potential strategies to mitigate enteric CH4 production by ruminants. Various biotechnologies are currently being explored with mixed results. Approaches to control methanogens through vaccination or the use of bacteriocins highlight the difficulty to modulate the rumen microbial ecosystem durably. The use of probiotics, i.e. acetogens and live yeasts, remains a potentially interesting approach, but results have been either unsatisfactory, not conclusive, or have yet to be confirmed in vivo. Elimination of the rumen protozoa to mitigate methanogenesis is promising, but this option should be carefully evaluated in terms of livestock performances. In addition, on-farm defaunation techniques are not available up to now. Several feed additives such as ionophores, organic acids and plant extracts have also been assayed. The potential use of plant extracts to reduce CH4 is receiving a renewed interest as they are seen as a natural alternative to chemical additives and are well perceived by consumers. The response to tannin- and saponin-containing plant extracts is highly variable and more research is needed to assess the effectiveness and eventual presence of undesirable residues in animal products. Nutritional strategies to mitigate CH4 emissions from ruminants are, without doubt, the most developed and ready to be applied in the field. Approaches presented in this paper involve interventions on the nature and amount of energy-based concentrates and forages, which constitute the main component of diets as well as the use of lipid supplements. The possible selection of animals based on low CH4 production and more likely on their high efficiency of digestive processes is also addressed. Whatever the approach proposed, however, before practical solutions are applied in the field, the sustainability of CH4 suppressing strategies is an important issue that has to be considered. The evaluation of different strategies, in terms of total GHG emissions for a given production system, is discussed.
在不改变动物生产性能的情况下减少反刍动物的肠道甲烷（CH4）排放，这既是减少全球温室气体（GHG）排放的一项策略，也是提高饲料转化效率的一种手段，是非常可取的。本文旨在介绍一系列已证实的和潜在的减少反刍动物肠道CH4产生的策略的最新情况。目前正在探索各种生物技术，结果好坏参半。通过接种疫苗或使用细菌素控制产甲烷菌的方法凸显了持久调节瘤胃微生物生态系统的困难。使用益生菌，即产乙酸菌和活酵母，仍然是一种潜在的有趣方法，但结果要么不尽人意，要么尚无定论，要么尚未在体内得到证实。消除瘤胃原虫以减轻甲烷生成很有前景，但应根据家畜生产性能仔细评估这一选择。此外，目前还没有农场去原虫技术。还对几种饲料添加剂进行了试验，如离子载体、有机酸和植物提取物。植物提取物减少CH4的潜在用途正重新受到关注，因为它们被视为化学添加剂的天然替代品，并且受到消费者的广泛认可。对含单宁和皂苷的植物提取物的反应差异很大，需要更多研究来评估其有效性以及动物产品中是否最终存在不良残留物。减少反刍动物CH4排放的营养策略无疑是最成熟且准备好在实地应用的。本文介绍的方法包括对构成日粮主要成分的能量型精饲料和粗饲料的性质和数量进行干预，以及使用脂质补充剂。还讨论了基于低CH4产量以及更可能基于其高效消化过程来选择动物的可能性。然而，无论提出何种方法，在实际解决方案应用于实地之前，CH4抑制策略的可持续性是一个必须考虑的重要问题。本文讨论了在给定生产系统中根据总温室气体排放对不同策略的评估。
