{Reference Type}: Journal Article {Title}: Turmeric rhizomes reduced in vitro methane production and improved gas production and nutrient degradability. {Author}: Kholif AE;Olafadehan OA;Gouda GA;Fahmy M;Morsy TA;Ammar H;Hamdon HA;Chahine M; {Journal}: Anim Biotechnol {Volume}: 35 {Issue}: 1 {Year}: 2024 Nov {Factor}: 2.141 {DOI}: 10.1080/10495398.2024.2371519 {Abstract}: The present study aimed to evaluate the effect of dry turmeric rhizomes on in vitro biogas production and diet fermentability. Turmeric rhizomes were included at gradually increased levels: 0, 0.5, 1, 1.5 and 2% of a diet containing per kg dr matter (DM): 500 g concentrate feed mixture, 400 g berseem hay and 100 g rice straw, and incubated for 48 h. Gas chromatography-mass spectrometry analysis showed that ar-turmerone, α-turmerone and β-turmerone were the major bioactive compounds in the rhizomes. Turmeric rhizomes increased (p < 0.01) asymptotic gas production (GP) and rate and lag of CH4 production and decreased (p < 0.01) rate of GP, lag of GP, asymptotic CH4 production and proportion of CH4 production. Turmeric rhizome administration linearly increased (p < 0.01) DM and fiber degradability and concentrations of total short-chain fatty acids, acetic and propionic acids and ammonia-N and quadratically (p < 0.05) decreased fermentation pH. It is concluded that including up to 2% turmeric rhizomes improved in vitro ruminal fermentation and decreased CH4 production.