Effect of increasing levels of seven tree species extracts added to a high concentrate diet on in vitro rumen gas output

This study was conducted to investigate the effects of increasing levels of extracts of Byrsonima crassifolia, Celtis pallida, Enterolobium cyclocarpum, Fraxinus excelsior, Ficus trigonata, Phoradendrom brevifolium and Prunus domestica on in vitro gas production (GP) and ruminal fermentation of a high concentrate diet. Plant extracts were prepared at 1g dry matter (DM)/8mL of solvent mixture (methanol:ethanol:water, 1:1:8) and added at levels of 0, 0.6, 1.2 and 1.8mL/g DM of a high concentrate diet. In vitroGP was recorded at 2, 4, 6, 8, 10, 12, 24, 48 and 72h of incubation. Increasing addition of extracts linearly increased (P<0.001), the GP(24), GP(48) and GP(72) (mL/g DM), and linearly decreased (P<0.001), the discrete GP lag time. Moreover, increasing extract doses linearly increased (P<0.001) the asymptotic GP and decreased (P<0.001) the rate of GP. GP(6) was not impacted by treatments and GP(12) increased linearly (P=0.01) with increasing addition of extracts. Rumen pH declined linearly (P<0.05) with increasing doses of extracts added. As no interactions (P>0.05) occurred between the extracts and doses, it could be conclude that all extracts positively modified rumen fermentation at doses of 1.2 to 1.8mL extract/g diet DM.