Evaluation of the glucose tolerance, insulin sensitivity and combined glucose and insulin tolerance tests for the assessment of glucose metabolism in Holstein dairy calves

摘要

In man and other mammalian species, prenatal and neonatal nutrition impact on health and metabolism in adult life. Metabolic disease is an important source of economic loss in the dairy cow (Singh et al, 2010). Evaluating the efficiency of carbohydrate metabolism in neonates may be useful to identify animals likely to be susceptible to metabolic disease during adulthood. Such specific predictors of future performance could be economically beneficial by facilitating animal selection. We tested the hypothesis that ad libitum, as opposed to restricted access to milk replacer from birth, would have a measurable impact on glucose/insulin dynamics by 2 weeks of age. A secondary hypothesis, that combined glucose and insulin tolerance tests (CGIT, Eiler etal, 2005) offer a simple, integrated evaluation of insulin sensitivity and glucose tolerance was tested by comparing changes in plasma glucose concentrations for all calves in response to separate CGIT, insulin sensitivity (IST) and glucose tolerance tests (GTT).