Chase L E, Wangsness P J, Kavanaugh J F, Griel L C, Gahagan J H
J Dairy Sci. 1977 Mar;60(3):403-9. doi: 10.3168/jds.S0022-0302(77)83879-4.
Four Holstein steers surgically prepared with a device for sampling from the portal vein were used to examine changes in concentrations of metabolites and insulin in portal blood with scheduled meals. The animals were fed a complete mixed ration (3.4 kcal/g digestible energy) twice daily at three intakes. Blood was sampled at 30, 15, 10, and 5 min before feeding and at 1, 3, 5, 10, 15, 30, 45, 60, and 120 min after feeding began. Average intakes of food at 30 min for the three intakes were 0 (control), 889 g (restricted), and 1425 g (fed). Packed cell volume increased rapidly within 15 min of initiation of the meal in fed steers, but the maximum change from pre-feeding was 6.6%. Insulin increased within 5 min with the restricted intake and at 15 min in fed steers. Portal volatile fatty acids and beta-hydroxybutyrate also increased within 15 min of initiation of the meal in fed steers, and glucose tended to decrease after feeding. Certain metabolites and insulin of portal bood changed rapidly with feeding. Additional studies are required to establish any role of these blood components in the short-term control of feed intake in steers consuming concentrate feeds.
选用4头通过手术安装了门静脉取样装置的荷斯坦公牛，以研究定时进餐时门静脉血中代谢物和胰岛素浓度的变化。这些动物每天分两次按三种采食量饲喂全混合日粮（可消化能量为3.4千卡/克）。在喂食前30、15、10和5分钟以及喂食开始后1、3、5、10、15、30、45、60和120分钟采集血液样本。三种采食量下30分钟时的平均采食量分别为0（对照）、889克（限饲）和1425克（饱饲）。饱饲的公牛在进食开始后15分钟内红细胞压积迅速增加，但与进食前相比的最大变化为6.6%。限饲时胰岛素在5分钟内增加，饱饲时在15分钟内增加。饱饲的公牛在进食开始后15分钟内门静脉挥发性脂肪酸和β-羟基丁酸也增加，喂食后葡萄糖有下降趋势。门静脉血中的某些代谢物和胰岛素随喂食迅速变化。需要进一步研究以确定这些血液成分在采食精饲料的公牛短期采食量控制中的作用。
