[Digestion of milk proteins in the abomasum of the preruminant calf].

Gastric digestion of milk proteins has been studied in the preruminant calf by analysing gastric effluents in the duodenum after the ingestion of 5 different diets: whole milk, skim milk, casein solution in water, casein solution with minerals, whey. The amino acid composition of the gastric effluents and HPLC analysis of the latter show that the major part of the whey proteins were evacuated rapidly without any proteolysis and after milk ingestion. On the contrary, all the caseins were largely proteolysed and arrived slowly in the gut. The major part of the peptides obtained came from alpha s1 casein. Only a few peptides, principally CMP, were quickly emptied from the stomach.