A Study of in vitro CH4 and C02 Production Effected by the Natural Tannin Sources, and Ground Maize to Grass as a Main Substrate

摘要

Two in vitro experiments were done to evaluate greenhouse gas production and organic matter digestibility. In the first experiment thirteen plant varieties were used for analysis of nutrients and condensed tannin content, then for gas production. Thesecond experiment was a completely randomized design with 5 treatments and 3 replications. The treatments were levels of ground maize at 0, 5, 10, 15 and 20 % (DM) added to the main substrate being Mom grass (Hymenachne acutigluma) corresponding to the GMO, GM5, GM10, GM15 and GM20 treatments. The results showed that in Expl, condensed tannin contents were higher than 9.5 % for the P. guajava leaves, mangosteen peel and S. samarangense leaves. They gave a lower CH4 production (less than 0.10 ml/gDOM) compared to others, while Arachis pintoi, P. purpureum and Brachiaria mutica, which were lower in condensed tannin content (less than 2.10 %) and produced higher CH4 production (more than 8.85 ml/gDOM). In Exp 2, the total gas, CH4 and CO, production (ml/gOM) at 96 h were significantly (P<0.05) different among the treatments and the CH4 production of the GM15 treatment was significantly higher (P<0.05) than those of the GMO, GM5 and GM10 treatment. Similarly, the significantly higher (PO.05) DOM (digestedorganic matter) values were found for the GM15 and GM20 treatment as compared to the GMO and GM10 treatments. The conclusion was that naturally condensed tannin sources from the plants (more than 9.5 %) gave a lower in vitro CH4 production, and no reduction of CH4 effected by increasing supplementation of ground maize to grass was found in the present experiment.