Potential digestibility of tropical grasses for swamp buffalo (Bubalus bubalis) in Thailand

We evaluated the suitability of six tropical grasses, Digitaria eriantha Steud, Paspalum atratum Swallen, Panicum maximum Jacq., Setaria sphacelata (Schumacher) Moss, Bracharia brizantha Stapf, and Chloris gayana Kunth, as feed for swamp buffalo (Bubalus bubalis) in Thailand. The grasses were cultivated in Okinawa, Japan, and their nutritional characteristics were evaluated by measuring chemical composition and in vitro digestibility. We also compared in vitro dry matter digestibility (IVDMD) results obtained using three different methods. Crude protein content was highest in B. brizantha (7.2%) and lowest in D. eriantha (5.4%). Averaged across all six grasses, the neutral and acid detergent fiber contents were 64.2% and 34.7%, respectively. The IVDMD measured by the buffalo rumen inocula method ranged from 64.2% for C. gayana to 71.4% for P. atratum. In comparison, the IVDMD measured using the cattle rumen inocula method ranged from 54.3% in C. gayana to 63.4% in P. atratum. Thus, the IVDMD of all experimental grasses was higher in buffalo (66.2%) than in dairy cattle (57.7%). The IVDMD of the experimental grasses by swamp buffalo could be estimated based on the high correlation (r=0.9847) with the value obtained using the dairy cattle rumen inocula method. Our results showed that all six grasses would be suitable as basal feedstuffs to supply crude protein and fiber for swamp buffalo