title: Estimation of intestinal protein digestibility of protein supplements for ruminants using a three-step enzymatic in vitro procedure.
abstract: This study included 33 samples with main focus on unprotected or rumen-protected rapeseed and soybean feedstuffs, which were analysed using an enzymatic in vitro procedure (EIVP) in order to determine intestinal crude protein (CP) digestibility (IPD) of ruminally undegraded CP. The EIVP involved the sequential digestion of samples with a protease from Streptomyces griseus, pepsin-HCl and pancreatin. Briefly, the EIVP started with determination of true protein. Feeds were incubated for 18 h in a buffer solution at a constant ratio (41 U/g) of S. griseus protease activity to feed true protein. The dried residues were incubated in pepsin-HCl solution for 1 h, and residues from this step were incubated in pancreatin solution for 24 h. Results appeared to have lower IPD dimensions than literature data of previous studies. In addition, a negative correlation became apparent between acid detergent fibre and IPD, as well as a positive correlation between CP, true protein and IPD. The EIVP in its current, strictly standardised form can be applied to develop a database that can be used for protein evaluation systems for establishing tabular values of IPD. Nevertheless, future studies may be hindered since sufficient reference values, i.e. in vivo data, are completely missing.
authors.affiliation: a Institute of Animal Science , University of Bonn , Bonn , Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: Hippenstiel
authors.forename: Andre
authors.initials: A
authors.lastname: Kivitz
authors.forename: Jens
authors.initials: J
authors.lastname: Benninghoff
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Südekum
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D029741:Brassica rapa; D004032:Diet / Q000662:veterinary*; D004044:Dietary Proteins / Q000378:metabolism*; D004063:Digestion; D004800:Enzymes, Immobilized / Q000378:metabolism; D012417:Rumen / Q000378:metabolism*; D012418:Ruminants / Q000378:metabolism*; D013024:Soybean Oil
chemical_list: D004044:Dietary Proteins; D004800:Enzymes, Immobilized; D013024:Soybean Oil
keywords: in vitro digestibility; protein; rapeseed oilmeal; rumen; small intestine; soybean oilmeal