Abstract
Rhodes grass at the early heading stage, Stylo and Siratro at the 10 weeks after clearing cut were harvested for ensiling. The plants were chopped to the length of about 1 cm and then Stylo (S) and Siratro (M) were individually mixed with Rhodes grass in following ratios: 0:100 (0), 25:75 (25), 50:50 (50), 75:25 (75) and 100:0 (100) as legume vs grass on wet weight. Each mixture was ensiled in duplicate in plastic experimental silos. The pH value, fermentation acid contents and in vitro dry matter digestibility using the oven dried sample (IVDMD) of resultant silages were measured. The value of buffering capacity and the content of water soluble carbohydrate in Siratro were higher than those of Stylo and Rhodes grass, while no large differences in the value of IVDMD were found between the plants. Mean scores by FLIEG's method of Stylo silages were 52 in S0, 41 in S25, 41 in S50, 31 in S75 and 24 in S100, and the scores of Siratro silages were 52 in M0, 24 in M25, 15 in M50, 1 in M75 and 5 in M100. Significant negative correlations were found between the ratios of mixing Stylo and Siratro with Rhodes grass and the socres of resulted silages (Stylo: r=-0.97, p<0.01; Siratro: r=0.91, p<0.05). On the other hand, as the mixing ratios of the legumes to the grass increased, the values of IVDMD of the silages decreased. In addition, there was significant positive correlation (r=0.98, p<0.001) between the fermentation quality and the IVDMD value of Siratro silages. It was suggested that the deterioration of fermentation quality of the silages made from legumes was closely correlated with the levels of buffering capacity of the ensiled materials.
