Mitigating greenhouse gas emissions from ruminants fed forage diets will reduce the carbon footprint of livestock production and the agricultural sector globally, thereby improving the overall environmental sustainability of ruminant production. In the current study, sheep housed in metabolism crates were offered 5 differing zero-grazed sward types. Methane production and methane yield from animals offered diets containing white clover ranked 14% and 27% lower, respectively, in comparison to the perennial ryegrass monoculture. The inclusion of herbs (chicory or plantain) led to an average reduction of 13% and 34% in urinary nitrogen concentration when compared to perennial ryegrass or perennial ryegrass and legume (white clover or red clover) treatments, respectively. Results from the current study support the implementation of binary sward mixtures (perennial ryegrass plus white clover, red clover, chicory, or plantain) as a viable strategy for mitigating methane emissions and nitrogen excretion from pasture-based sheep production systems.

Read the full article in the Journal of Animal Science.