Chapter 17 Dietary influences on pancreatic α-amylase expression and secretion in ruminants

Abstract

This chapter explains how diet and post-ruminal nutrients influence pancreatic α-amylase expression and secretion in ruminants. Specific mechanisms involved in dietary regulation of α-amylase expression and secretion are also discussed. While the majority of starch consumed is fermented in the rumen, considerable quantities pass to the small intestine. The starch that passes to the small intestine is first hydrolyzed by pancreatic α-amylase. α-amylase provides the glycosidic activity secreted in pancreatic juice. The production and secretion of α-amylase is an important component regulating the digestive efficiency of starch in ruminants fed high-concentrate diets. Diet and post-ruminal nutrients do influence the expression and secretion of pancreatic α-amylase. At the cellular level, diet and post-ruminal nutrients appear to regulate expression of α-amylase at the translational level. Increases in the pancreatic protease and α-amylase activities are also observed when dietary protein or starch is replaced by a protein hydrolysate or glucose, respectively.