The effect of diet on the secretion of parotid saliva by sheep. II. Variation in the rate of salivary secretion

Abstract

The rates of parotid salivation of two sheep were recorded during periods of resting (when not eating or ruminating), eating, and ruminating. Diets differing in both quality and quantity were offered to the sheep, and continuous recordings of the salivation rates of each sheep were made for 24 hr during each dietary period.

The mean rate of secretion during rest was lowest at the beginning of a rest period and increased gradually to a peak at the end of the rest period. The mean secretion rate at rest was lowest during the rest period following a meal, and increased gradually to reach a peak during the rest period before the next meal. The secretion rat e during rest was increased by partially evacuating the rumen, and decreased by introducing fluids into the rumen.

The mean secretion rates during rest and rumination were higher when the sheep were fed ground hay than when they were fed long hay. The mean secretion rate during rest was increased when the food intake was increased.