Digestion of proteins of varying degradability in sheep. 3. Apparent and true digestibility in the small intestine and ileal endogenous flow of N and amino acids.

Abstract

Sugarbeet pulp, citrus pulp, sugarbeet molasses and minerals and vitamins were mixed with different amounts of groundnut expeller, potato protein, peas or dried brewers' grains to give 6 concentrates with protein solubility from 7 to 51%. The concentrates (600 g daily) were given with rye grass (300 g daily) to 2 Texel wethers with an infusion tube into the abomasum and with cannulae in the cranial duodenum and terminal ileum. Apparent digestibility of amino acid nitrogen in the small intestine was 57.0 to 73.2% and increased with increasing amounts of protein entering the small intestine. Mean true digestibility in the small intestine was 90.3%. Apparent and true digestibilities of individual amino acids varied considerably. Of protein leaving the small intestine 75% was endogenous (non-ammonia N 321 mg/kg^0.75 daily). (Abstract retrieved from CAB Abstracts by CABI’s permission)