In vitro fermentation of corn silage using rumen fluid buffered or not and different sample amounts

Methodological variations in the amount of sample incubated and the type of rumen fluid used are commonly observed. This study evaluated the effect of three sample amounts (0.6, 1.3 or 2.6g DM 100mL-1 of rumen fluid) incubated in rumen fluid buffered (BRF-buffered rumen fluid) or not (PRF-pure rumen fluid) on total gas volume (TV), methane (CH4) production, dry matter degradation (DM Deg) and final pH of corn silage incubated in vitro. The highest DM Deg was reached with the lowest amounts of sample (0.6 and 1.3g of DM 100mL-1 of rumen fluid). The sample amount of 2.6g associated with PRF reduced CH4 production (P<0.05), compared with the amounts of 0.6 and 1.3g DM 100mL-1, which had similar CH4 production (P>0.05). The use of BRF caused no effect on CH4 production (P>0.05), independent of the sample amount. Increasing the amount of substrate resulted in lower final pH of incubation in both fluids (P