Abstract: A study was conducted to investigate the effect of addition of three plant extracts on in vitro gas production, ruminal fermentation, methane production and ruminal digestibility. Three plant extracts including Tea Saponin (TS), Mulberry Leaf Extract (MLE) and Ecdysterone (ECD) were added to the substrate at 1.6, 1.25 and 0.2 mg g-1, respectively. When plant extracts were added all the plant extracts showed a similar pattern of Gas Production (GP). Compared with Control (CON), MLE and ECD had numerically higher GP at all time points of incubation but TS showed higher GP only at 1st 28 h incubation and then decreased afterwards. Shorter lag time and faster rate of gas production were observed for TS than ECD, MLE and CON, although the difference was not significant (p>0.05). No matter what time points were taken, each of plant extracts did not exhibit significant changes in methane production and proportion (p>0.10). Compared with CON, the addition of plant extracts did not change in vitro ruminal pH , ammonia concentrations, total VFA (p>0.05) and the ratio of acetate to propionate (p>0.10) but decreased molar proportions of both butyrate and minor acid (including valerate, isobutyrate and isovalerate) (p<0.05), Digestibilities of DM (IDDM) and OM (IDOM) were 38.0 and 35.3%, 41.3 and 44.9%, 39.1 and 38.0% and 41.3 and 37.2% for CON, TS, MLE and ECD, respectively. Although, plant extracts of TS, MLE and ECD did not significantly (p>0.05) change the IDDM relative to CON, TS had higher IDOM than CON (p<0.05). It is concluded that tea saponin showed a potential value as a plant extract feed additive used by ruminant animals. Further study is needed to provide more information about animal performance responses to the addition of plant extracts to the diets of ruminants.
Manlin Wei, Liping Ren, Zhenming Zhou and Qingxiang Meng, 2012. Effect of Addition of Three Plant Extracts on Gas Production, Ruminal Fermentation, Methane Production and Ruminal Digestibility Based on an in vitro Technique. Journal of Animal and Veterinary Advances, 11: 4304-4309.