Studies on the alimentary tract of the merino sheep in South Africa. XVIII. The effect of fasting on the activity of the ruminal flora of sheep and cattle

Abstract

1. The effects of starvation on the consistence of the ruminal ingesta and the activity of the ruminal flora have been studied. 2. The ruminal contents were found to become progressively more watery during starvation although there was still a large volume present even after 96 hours without food. 3. Both the fermentation of sugar and the digestion of cellulose were markedly depressed after 48 hours starvation. 4. On a low protein diet of grass hay the appetite returned to normal immediately after starvation but on a higher protein diet of lucerne hay the consumption after starvation was low and only returned to normal after 3 to 5 days. There was evidence to show that the sheep regulated their protein intake in accordance with the adaptation of the ruminal flora. This did not appear to apply to the same extent to cattle.