Isoacid supplementation influences feed sorting, chewing behaviors, and enteric methane emissions differentially in mid-lactation dairy cows depending on dietary forage level.

Past studies have shown that isoacids (ISO) improve dairy cow performance, with effects varying based on dietary forage levels, leading us to speculate that ISO supplementation may also differentially affect enteric methane (CH) emissions depending on dietary forage levels. Therefore, our primary objective was to examine the effects of ISO supplementation on enteric CH emissions in lactating dairy cows fed 2 forage NDF levels (FL), along with monitoring feed particle sorting and chewing behaviors to assess any potential interactions. Sixty-four (64) mid-lactation Holstein cows were utilized in a 10-wk long randomized complete block design trial.