The relationship between gastrointestinal hormones and nutrients in calves around the weaning stage.

本研究的目的是确定断奶前后饲喂、循环葡萄糖和挥发性脂肪酸（VFA）对犊牛血液GLP-1和ghrelin浓度的影响。在实验1中，断乳增加了GLP-1的基础血液水平，但ghrelin的基础水平降低。血中这些激素的变化与血糖、VFA水平有关。在实验2中，VFA注射诱导血液GLP-1的更大的增加和血液ghrelin水平的更大的下降在断奶阶段附近。然而，葡萄糖注射液不影响这些激素浓度。实验3中，与断奶前相比，GLP-1和ghrelin注射液显著刺激断奶后胰岛素和GH的分泌。

Our objectives were to determine the effects of feeding, circulating glucose and volatile fatty acids (VFA) on blood GLP-1 and ghrelin concentrations in calves around weaning stage. In experiment 1, weaning increased basal blood level of GLP-1, but basal level of ghrelin was decreased. And the changed in blood these hormones were related the blood glucose and VFA levels. In experiment 2, VFA injection induced a greater increase in blood GLP-1 and a greater decrease in blood ghrelin levels around weaning stage. However, glucose injection was not affected these hormones concentrations. In experiment 3, GLP-1 and ghrelin injection were strongly stimulated insulin and GH secretions after weaning compared with that before weaning.