Effect of different dietary levels of Quebracho tannin extract on nitrogen and fiber digestibility and post-ruminal microbial protein flow in heifers

摘要

The effect of condensed tannins (CT) on protein digestion in ruminants appears to be dosage-dependent. While low to moderate CT concentrations are considered to increase rumen-escape protein, higher CT intakes may inhibit microbial crude protein (MCP)synthesis and decrease nutrient digestibility (Barry and McNabb, 1999). Our aim was thus to determine how graded dosages of a Quebracho tannin extract (QTE; 75% total phenolic content) influence MCP flow and digestibilities of neutral detergent fiber (NDF), acid detergent fiber (ADF), nitrogen (N), and acid detergent insoluble N (ADESf).