Effect of Glucocorticoids and Limiting Nursing on the Carbohydrate Digestive Capacity and Growth Rate of Piglets

The influence of glucocorticoid administration and limited nursing on piglet carbohydrase enzyme development and subsequent growth was examined in three experiments using 371 piglets. Treatments in the first two experiments were formed by the factorial arrangement of hydrocortisone (-HYD or +HYD) and limited nursing (-LN or +LN) imposed form d 14 to weaning (d 28). Hydrocortisone was replaced by adrenocorticotropic hormone (ACTH) in the third experiment. Growth rates were severely depressed by HYD (P less than .01), LN (P less than .001) and to a lesser extent (P less than .06) by ACTH during the last 2 wk of lactation. During the first 14 d postweaning, piglets continued to grow more slowly following HYD treatment (P less than .01), whereas LN piglets grew more rapidly than those allowed to suckle normally. Although piglets were smaller at weaning after HYD injection (P less than .01), relative weights of liver, pancreas and small intestine were increased (P less than .05). Only adrenal weights were increased by ACTH (P less than .09). Pancreatic and intestinal amylase activities were increased two- to three-fold by HYD injection (P less than .05) but were unaffected by ACTH or LN (P greater than .10). Sucrase and maltase activity increased linearly with age (P less than .001). This rate of increase was numerically enhanced by glucocorticoid treatment and LN. The normal decrease in lactase activity was accelerated by LN and HYD injection, with the greatest depression caused by the combination of LN and either HYD or ACTH administration (P less than .05). Glucocorticoid administration to nursing piglets can evoke premature elevation of the carbohydrase enzymes necessary for initiating the hydrolysis of starch.