Diet and caecal motility in sheep.

The electrical activity of the caecum was recorded during periods of two months in 5 ewes receiving different diets. For a similar amount of dry matter ingested, the frequency of caecal contractions was diminished on concentrates with urea versus hay ad libitum but not on concentrates without urea. The frequency also decreased when the level of food intake on hay diet or on concentrates without urea diet was reduced. On a daily meal food intake, induced caecal hyperactivity occurred or hay and inhibition for concentrates with urea. The postprandial hyperactivity had a ruminal origin and was mediated by the vagus nerves. The inhibitory effects of urea were correlated with the ruminal production and ammonia and its diffusion into the abdominal cavity.