In situ ruminal degradability of Pennisetum purpureum Cuba CT-115 in commercial river buffaloes and Zebu

The in situ ruminal degradability of the dry matter (DM), the fiber (NDF) and the total nitrogen (Nt) of the Cuba CT-115 (Penniselum purpureum cv CUBA CT-115) was studied in river buffaloes and cattle. Three adult crossbred Zebu bulls and three adult commercial river buffaloes, with average weight of 450 and 590 kg and cannulated in the rumen according to a completely randomized design were used. The diet consisted basically of fresh CUBA C-115 forage and a soybean supplement. Sixty nylon bags (14 x 8.5 cm), previously weighed, were used, in which 5 g of forage were weighed. The duplicated bags were randomly selected for each sampling time and animal and they were incubated in the rumen for 8, 12, 24, 48 and 72 h. The digestion residues, washed and dried, were determined the DM, the NDF and the Nt. The results did not show differences in the degradability of the CUBA CT-1 15 DM, which was of 59.22 % for the bulls and 55.25 % for the buffaloes. Nitrogen was the most extensively nutrient degraded in the rumen (59 to 62 %). The 18 % of this fraction was rapidly degraded and between 41 and 44 %, degradation was slower. The degradation rate was much higher in the buffaloes. The microbial colonization of the fiber (lag phase) was much more rapidly, 2.33 vs 4.97, (P < 0.05) in buffaloes than that of the Zebus. The results obtained in this study suggest that buffaloes use lest time in the colonization of the fiber and they achieve a superior effective degradability of the nitrogen fraction. Therefore, it is possible they make a more efficient use of the forage than Zebus.