The objective of this study was to determine the effect of the heat treatment of full-fat soyabean (FFSB) and solvent extracted soyabean meal (SBM) on the in situ dry matter (DM) and protein degradability, and in vitro gas production kinetics of the protein sources. Ruminal disappearance of DM and crude protein (CP), and in vitro gas production were determined after 0, 4, 8, 16, 24, 48 and 72 h...