Study of the use of a protease with the van Soest procedure

Several trials were performed to elaborate a method facilitating NDF filtration and to reduce analytical errors on feeds rich in proteins. Three pronases (P5147, 33635, Serva; 53702, Calbiochem) were compared at various concentrations. The pronase 53702 was retained to elaborate the NDF pretreatment procedure which includes 1–10 min of hydrolysis with distilled water, with 2–15 min of hydrolysis with 60 u of α-amylase (Termamyl 120 L) and 3–15 min hydrolysis with 100 μ of pronase 53702. Applied to a set of 20 various common ingredients this pretreatment largely facilitated the filtration. As results there were decreases of the NDF content (2.43% of dry matter) and of the residual N of NDF (0.50% of NDF).