Effect of glycerol in combination with alfalfa on in vitro gas production and microbial protein synthesis

no glycerol (2.78 vs. 3.65). Reduced microbial mass (185.5 vs. 240.5 mg g � 1 DM) was observed for CG compared with PG. The LNSCES treatment had lower microbial protein synthesis and propionic acid production in relation to HNSC. No significant interaction was observed between the effect of NSC content of alfalfa and glycerol utilization. When effects were studied separately, results indicate that increasing NSC in alfalfa stimulates the synthesis of microbial protein. Also, the addition of glycerol promotes the synthesis of glucose precursors. Finally, the type of glycerol has an impact on results obtained suggesting caution when extrapolating results for PG to CG.