"Methane production used to be viewed as a problem at cattle ranches and dairy farms, but methane itself is a highly energetic biogas that can be used as fuel. Harnessing it might prove difficult considering that current social graves do not favor open flatulence even for the sake of renewable energy. However, certain diets richer in alfalfa and flaxseed have been proven to reduce methane production in cows, which could potentially solve that problem (13)."
Honestly looking back historically, meat once a month wouldn't be strange