Changes in composition and pH of digesta along the gastrointestinal tract of sheep in relation to scouring induced by wheat engorgement

Abstract

Changes in the composition of digesta along the gastrointestinal tract of scouring sheep fed on wheat grain ad libitum were studied relative to sheep fed on lucerne hay ad libitum.

Wheat engorgement significantly (P < 0.005) depressed the pH of the digesta in the reticulorumen and the digestive tract distal to the jejunum. A mean total volatile fatty acids concentration of 10.3mM in the caecum of scouring sheep was significantly lower than the mean of 51.6mM in sheep fed on lucerne hay.

Net absorption of water was negligible in the colon of scouring sheep as digesta were only 13.7–14.7% dry matter, whereas in sheep fed on lucerne, the dry matter of digesta increased from 14.7% in the caecum to 27.9% at the rectum.