In vitro evaluation of selected compounds affecting ruminal fermentation and methane production

(18%) and modest increase in propionate did not differ from the control (P > 0.05). Our findings indicate that CAR and 2NEOH exert distinct effects on rumen fermentation and methanogenesis. Notably, the high-dose combination negatively impacted fermentative parameters, whereas the low-dose combination performed similarly to 2NEOH alone. Further investigation into how these compounds modulate the rumen microbiota will help elucidate the mechanisms underlying their differential effects before they can be tested in vivo.