The effect of diet on the secretion of parotid saliva by sheep. III. Observations of the secretion of saliva by grazing sheep

Abstract

The parotid saliva secreted by three grazing sheep was recorded by exteriorizing and cannulating one parotid duct of each sheep, and collecting the saliva into carts that were harnessed to the sheep. The sheep were grazed on an annual pasture in a Mediterranean climate and collections were made during spring, summer, autumn, and winter. In each season, recordings were also made of the pasture intake, pasture availability, and the behaviour of the grazing sheep. The mean daily secretion of saliva from one gland was 3.42 l. in autumn, 4.05 l. in winter, 6.69 l. in spring, and 4.07 l. in summer. In spring, the mean secretion from one sheep was 7.92 l./day. The changes in secretion did not appear to be related to the pasture intake, or to the grazing behaviour of the sheep.