Effect of Insulin-Induced Hypoglycemia on Cessation of Macromolecular Transport in the Neonatal Calf

Abstract

The effect of hypoglycemia on the absorption of colostral Ig was studied in 12 neonatal calves. Hypoglycemic calves received 1 cc (100 units) of insulin at birth; control calves received 1 cc of saline. Two dietary regimens were imposed; colostrum was fed at birth or at 24 h. Glucose, insulin, and IgG were measured in venous blood. Insulin induced decreases in circulating glucose in insulin-treated calves from 12 to 42 h postnatally; insulin concentrations were significantly higher from 12 through 24 h. Concentrations of glucose also were decreased in calves deprived of initial colostrum compared with those fed at birth over the same period, although insulin concentrations were not different. Time of closure was delayed in insulin-treated calves relative to saline-treated calves (40 and 29 h, respectively) and in calves deprived of initial colostrum relative to those fed at birth (45 and 23 h, respectively). Glucose availability may influence timing of closure in the calf, although the decreased rate of absorption of IgG in hypoglycemic calves prevents them from realizing any benefit in peak IgG concentrations higher than those of their normoglycemic counterparts. © 1993, American Dairy Science Association. All rights reserved.