Tools for decreasing enteric methane production by ruminants ; Leviers d'action pour réduire la production de méthane entérique par les ruminants

National audience ; This paper reviews the strategies to reduce methanogenesis in ruminants and their applicability on farm. It is known that increasing the percentage of concentrate decreases the production of methane per kg of dry matter intake. This effect is especially important at high levels of concentrate. Cereals decrease more methane emission than concentrates rich in fibre. Lipid inclusion in diets significantly decreases methane emission. Among forages, maize silage diets result in lower emissions than hay or grass silage diets, but differences in vegetation stages or between grasses and legumes are low and sometimes controversial. Alarge number of plant extracts and additives with different modes of action have been assayed. Plants rich in tannins or tannin extracts result in methane mitigation, but the risk of impairing diet digestibility has to be considered. The long term efficacy of many of these additives still needs to be evaluated. Biotechnologies that reduce dihydrogen available for methanogenesis are promising but need further testing. Increasing the level of production of animals results in a decrease in methane production, which is especially significant when methane is expressed per kg of milk or meat. There are also differences between animals in their global productive efficiency, evaluated through the residual feed intake. The most efficient animals produce less methane per kg of milk or meat. This paper stresses the need to look beyond enteric methane mitigation, and to evaluate the efficacy of mitigation strategies on all greenhouse gases associated to ruminant production. ; Cet article fait le point des connaissances sur différentes pistes pour réduire la production de méthane entérique par les ruminants, en privilégiant les approches in vivo, et évalue les possibilités d'application pratique. Il est connu que l'accroissement du pourcentage de concentré dans la ration réduit la production de méthane par kg de matière sèche ingérée. Cet effet est toutefois plus sensible pour des ...