Effects of Processing Methods on Ruminal Degradation of Broomcorn and Barley Grains

A ruminal in situ experiment using three fistulated ewes was conducted to determine dry matter (DM) and crude protein (CP) degradation of steam–flaked broomcorn (SFBr), ground broomcorn (GBr) and ground barley (GB). Grain samples were suspended in the rumen of sheep for 0, 2, 4, 8, 16, 24 and 48 h. Nylon bags were washed with tap water after removal. Effective degradability of DM at outflow rates of k = 0.05 and k = 0.08 h-1 was significantly higher for SFBr than for GBr (59 and 53% vs. 43 and 35%). SFBr has considerably higher soluble DM than GBr and GB. Insoluble DM of SFBr was lower than that of GBr and GB. Solubility of CP in broomcorn grain was significantly decreased by steam–flaking, but degradation rate of insoluble CP was not altered. Results from this study showed that SFBr supplies the major source of availabe nutrients for rumen microorganisms compared with GBr. In other words, using the most efficient processing method for ruminants will be necessary.