Heat stress increases enteric methane emissions yield and intensity while impairing rumen function and productivity in lactating dairy cattle.

Heat stress represents an increasing challenge to dairy sustainability. While its negative effects on rumen function and milk production are well established, its impact on enteric methane emissions has remained largely understudied, until now. Recent research demonstrates that heat‑stressed cows emit significantly more methane per unit of feed intake and per unit of milk produced. This results in higher methane yield and methane intensity, reflecting a decline in efficiency: cows produce less milk while generating proportionally more greenhouse gases.

By Onan-Martinez D., de Bari M.A.T., Olmo H. et al.