title: Proteolytic activity of ruminal digesta during the feeding cycle in sheep receiving grass hay/concentrate or maize silage/concentrate diets.
abstract: Proteolytic activity was measured by the digestion of 14C-labelled casein in digesta removed from the rumen of four sheep receiving a grass hay/concentrate diet and four sheep receiving a maize silage/concentrate diet. Samples were removed immediately before feeding and at 2-h intervals after feeding up to 12 h. Animals on both diets produced similar proteolytic activities (1.83 (S.D. 0.41) and 2.14 (S.D. 0.61) mg 14C-casein hydrolysed (ml ruminal fluid)-1 h-1 with the maize silage- and grass hay-based diets, respectively). Time after feeding had no effect on proteolytic activity, but between-animal variation was consistent and highly significant, with the highest-activity animals having activities 64 and 74% higher than the lowest-activity animals on the two diets, respectively.
authors.affiliation: Rowett Research Institute, Bucksburn, Aberdeen, UK. rjw@rri.sari.ac.uk
authors.forename: R J
authors.initials: RJ
authors.lastname: Wallace
authors.forename: S J
authors.initials: SJ
authors.lastname: Wallace
authors.forename: N
authors.initials: N
authors.lastname: McKain
mesh_terms: D000821:Animal Feed; D000818:Animals; D002364:Caseins / Q000378:metabolism; D004032:Diet; D004435:Eating; D005772:Gastrointestinal Transit; D010447:Peptide Hydrolases / Q000378:metabolism*; D006109:Poaceae / Q000378:metabolism; D012417:Rumen / Q000378:metabolism*; D012756:Sheep / Q000502:physiology*; D012820:Silage; D003313:Zea mays / Q000378:metabolism
chemical_list: D002364:Caseins; D010447:Peptide Hydrolases