Effect of Age on the Exocrine Pancreatic Secretion of the Preruminant Milk-fed Goat

Abstract

The effect of age on the exocrine pancreatic function was studied in fifteen Granadina goat kids during the second, third and fourth postnatal week. The animals, chronically catheterized, were bottle-fed on goat milk twice a day. Pure pancreatic juice was collected from 1 hour before and throughout 8 hours after milk ingestion. Pancreatic flow rate, bicarbonate and chloride concentrations, total protein content and enzyme activities were determined. In resting conditions, pancreatic flow rate augmented with age, probably reflecting an increase in body and pancreas weight. Resting amylase and lipase activities recorded significant increases during the fourth week of life. That may be associated, respectively, to the immediate change to a high-starch diet and to a simultaneous decrease in the salivary lipase levels. Our results also showed age-related differences after ingestion of milk, mainly concerning the volume response and the lipase output. The latter can be explained in the same way as regarding resting conditions. With respect to the volume response, several factors could be implicated, such as the circulating levels of gastrointestinal hormones, the sensitivity of the pancreas to such stimuli, the maturation degree in the secretory mechanisms of the gland or the development of the digestive tract.