Comparative effects of Gamal (Gliricidia sepium)-based diets supplemented with Gambier (Uncaria gambir) or direct-fed microbials on rumen fermentation, nutrient digestibility, microbial protein synthesis, and methane mitigation in beef cattle: An in

Gamal-based diets supplemented with Gambier or DFM positively modified rumen fermentation, but through distinct mechanisms. DFM improved digestibility and fermentation stability, whereas Gambier achieved the greatest CH₄ mitigation at 1% inclusion. Gambier represents a promising, locally available option for sustainable methane reduction in tropical ruminant feeding systems, supporting future in vivo validation.