The effects of feeding more milk on periprandial plasma glucagon-like peptide-2 concentrations in preweaning dairy calves

The objective of this study was to evaluate periprandial plasma concentrations of glucagon-like peptide-2 (GLP-2), glucose, and β-hydroxybutyrate (BHB) in response to a milk meal in preweaning dairy calves. Nineteen Holstein heifer calves were fed either a high (10 L/d; n = 9) or low (5 L/d; n = 10) amount of pasteurized whole milk from d 2 to 50 of life. Calves were housed in individual pens for the first 19 ± 3 d and fed only milk before being moved to a group pen, where they remained on their respective milk treatment and offered calf starter ad libitum. Blood samples were collected sequentially for 240 min following their milk meal at wk 3, 5, and 7 of life to characterize the periprandial response in plasma concentrations of GLP-2, glucose, and BHB. Baseline plasma glucose concentrations were increased, when a high amount was fed; however, we found no difference in area under the curve. Feeding a high amount of whole milk had no effect on baseline or periprandial plasma BHB concentrations. Baseline plasma GLP-2 concentrations decreased as calves aged. Feeding a high amount of whole milk tended to significantly increase baseline GLP-2 concentrations throughout compared with calves fed a low amount. The periprandial response of GLP-2 was not biphasic until calves were 7 wk old. In conclusion, feeding a high amount of milk may increase GLP-2 concentrations in preweaning calves, although its exact mechanism is unknown.