Insulin-like growth factor-I, GH, insulin and glucagon concentrations in bovine colostrum and in plasma of dairy cows and neonatal calves around parturition

1. 1. The IGF-I concentrations in colostrum on days 1 and 2 after parturition were higher than those in cow and neonate plasma. 2. 2. The modest increase in GH concentrations in cow plasma around parturition would not be enough to stimulate IGF-I release by tissues. 3. 3. The concentrations of insulin, GH and glucagon in colostrum were substantially lower than those in plasma.