Effects of Age and Diet on the Secretion of Pregastric Esterase in Calves

Abstract
The effects of age and diet on the quantity of pregastric esterase secreted during the nursing of milk were studied in 6 Holstein calves. During the first 180 days of life, there was no appreciable change in enzyme secretion. Limited observations on 2 calves suggest that this trend continues through at least 1 yr. of age. Calves sustained on a diet of hay and grain secreted, when nursing milk, approximately the same quantity of pregastric esterase as did animals restricted to a diet of milk. The enzyme output during the actual consumption of hay and grain, however, appeared to be considerably less than that stimulated by nursing. There was no correlation between total volume of saliva and the output of pregastric esterase.