Delayed Colostrum Feeding Affects lGF-l and Insulin Plasma Concentrations in Neonatal Calves

摘要

In the neonatal calf, insulin-like growth factor I (IGF- I) concentrations are markedly influenced by the amount of colostrum intake after birth, although colos- tral IGF-I is barely absorbed. In this study we have investigated effects of delayed colostrum intake in neo- natal calves on metabolic traits and on IGF-I, IGF bind- ing proteins (lGFBP), growth hormone (GH), and insu- lin concentrations in plasma. Calves received colostrum of first milking starting at 2 (GrA), 6 (GrB), 12 (GrC), and 24 h (GrD) after birth. Before third colostrum in- take plasma total protein concentrations were higher in GrA than in GrD and plasma glucose concentrations were higher in GrC than GrD. Plasma IGF-l concentra- tions at first and third colostrum intake were higher in GrA than in GrD. Plasma IGFBP-2 concentrations before first colostrum intake were higher in GrD than in GrA and GrC, and were higher before third colostrum intake in GrD than in GrA. Plasma IGFBP-3 concentra- tions before first colostrum intake were lower in GrD than in GrA, and before third colostrum intake were lower in GrD than in GrA and GrB. PostprandiaI plasma insulin concentrations after first colostrum in- take were higher in GrA than in GrC and GrD. In conclusion, the plasma lGF-l and insulin status are markedly, albeit transiently, decreased in calves fed colostrum with a delay of 12 to 24 h, and the decreased concentrations of plasma IGF-I were associated with decreased IGFBP-3ffGFBP-2 ratios.