Sustainability of Animal-Sourced Foods - how to deal with farting cows...

I've just read through a number of articles in a Special Feature section of  the most recent issue of PNAS on the future of animal and plant sourced food. After a balanced lead article by Qaim et al., a following article that really caught my eye was "Mitigating methane emissions in grazing beef cattle with a seaweed-based feed additive: Implications for climate-smart agriculture."  First line of it's abstract is "This study suggests that the addition of pelleted bromoform-containing seaweed (Asparagopsis taxiformis) to the diet of grazing beef cattle can potentially reduce enteric methane (CH4) emissions (g/d) by an average of 37.7% without adversely impacting animal performance."