A simplified management of the in situ evaluation of feedstuffs in ruminants: Application to the study of the digestive availability of protein and amino acids corrected for the ruminal microbial contamination.

The ruminal effective degradability (RED) and intestinal effective digestibility (IED) for dry matter, crude protein (CP) and amino acids (AA) were estimated by a simplified in situ method using pooled samples from rumen-incubated residues, which represented the ruminal outflow of undegraded feed. The effect of microbial contamination in the rumen was corrected using (15)N infusion techniques. Studies were carried out for soybean meal (SBM), barley grain (BG) and lucerne hay (LH) in three wethers cannulated in the rumen and the duodenum.