Ruminants have no genes for methane production in their genome

Ruminants have no genes for methane (CH4) production in their genome. The reasons for a regularly observed inter-animal variation in CH4-formation have not been fully explained yet. An assessment of existing differences between animals based on data reflecting individual differences in the anatomy of the gastrointestinal tract and/or in digestive physiology could help elucidate the links with inter-animal variation in CH4 yield. There is preliminary evidence that the individual rumen volume and structure as well as the ruminal passage rate of the digesta contribute to the variability of CH4 production. The causes for the inter-animal variance in CH4 formation must be scrutinized consistently in order to avoid breeding mistakes (= establishment of a one-sidedly intensive selection of breeding animals for reduced CH4 yield).