The prepartum sow: Consequences of stimulation with ACTH or a synthetic glucocorticoid, with observations on the liver carbohydrate metabolism of its neonates

Abstract

Twelve pregnant sows were used to determine the influence of prenatal stimulation of the adrenal glands with ACTH and the use of a synthetic glucocorticoids on the liver carbohydrate metabolism of their neonatal pigs. On the 105th day of gestation the sows were randomly assigned to one of the three following treatments: Isoflupredone injection and either ACTH or saline infusion. The sows' cortisol increased (P < 0.05) in response to ACTH but not to isoflupredone. Glucose levels remained constant in all groups. Body weight was reduced (P < 0.05) in piglets born to ACTH-treated sows but not in those treated with isoflupredone. ACTH treatment resulted in a reduction of body:liver weight ratio in the piglets and increase in total phosphorylase activity. Phosphorylase activity was further increased by 6 h (P < 0.05). Liver glycogen and glucose were similar in all groups at birth and only glycogen decreased by 6 h (P < 0.05). Thus, it is concluded that elevation of cortisol through maternal stimulation with ACTH produces a piglet which, although lighter at birth, has a lower body:liver weight ratio and a more active glycogenolytic mechanism. It is possible, therefore, that these physiological phenomena may play a successful role in maintaining neonates active until suckling. Key words: Cortisol, liver, glucose, piglet, ACTH, isoflupredone