Published online by Cambridge University Press: 18 August 2016
Responses to intravenous glucose challenge (no. = 26) and basal metabolite and hormone concentrations (no. = 68) were determined in dairy cows selected for high (HFI) or low (LFI) milk-fat concentration but with similar 40 g/kg fat-corrected milk (FCM) yields. All cows were given a mixed diet ad libitum. Following a glucose challenge the insulin release was higher (P < 0·05) and the glucose clearance rate faster (P < 0·05) in the HFI cows compared with the LFI cows. Basal plasma concentrations of the metabolites alanine, β -hydroxybutyrate, glucose, non-esterified fatty acids and urea and the hormones insulin-like growth factor-1 (IGF-1), insulin and leptin were not influenced by selection line.