Meta-analysis on the effects of lipid supplementation on methane production in lactating dairy cows

A meta-analysis was conducted to statistically determine the effects of lipid supplementation on methane (CH4) production, milk production, and milk composition of lactating dairy cows. For this purpose, it database was built using seven scientific publications (25 diets) available in the literature and reporting the effects of lipid supplementation on CH4 production, milk production, and milk composition. Lipid supplementation decreased (P < 0.05) dry matter intake (DMI) by 6.4% compared with control diets, whereas production of milk and 4% FCM and milk composition were not changed (P > 0.05). Lipid supplementation decreased (P < 0.05) CH4 production by 9%, either expressed as MJ d(-1) or as a percentage of gross energy intake (GEI), digestible energy intake (DEI), or metabolizable energy intake (MEI). This reduction was mainly a consequence of it decreased DMI.