Ortigues I, Martin C, Durand D, Vermorel M
Laboratoire Croissance et Métabolismes des Herbivores, INRA, Theix, Saint Genès Champanelle, France.
J Anim Sci. 1995 Feb;73(2):552-64. doi: 10.2527/1995.732552x.
A study was conducted using four preruminant calves to determine the contribution of portal-drained viscera, liver, and hindquarters to circadian changes in total energy expenditure, after removing variations due to behavioral patterns. Indirect calorimetry and in vivo arterio-venous techniques were used. Standing time was longer (P < .01) after the meals and shorter (P < .01) at night. These variations were associated with higher (P < .01) energy cost of standing immediately after the meals and lower (P < .01) ones at night. When these behavioral effects were removed, total energy expenditure of lying calves was shown to be stable between the morning and evening meal, to increase by 11.5% and remained elevated during the 6 h after the evening meal, and to reach the lowest values at night. Portal-drained viscera and liver contributed 32.8 to 53.7% and 29.1 to 32.2%, respectively, to the circadian variations calculated for calves that were always standing. Changes in splanchnic tissue energy expenditure resulted from combined modifications in blood flow and O2 extraction rate. The contribution of hindquarters could not be clearly established. Overall, portal-drained viscera, liver, and hindquarters contributed 17.2, 12.8, and 18.0%, respectively, to total energy expenditure of standing calves. Their respective in vivo metabolic activities averaged 1.08, 2.10, and .25 mumol of O2 consumed.min-1.g-1 of fresh tissue.
采用四头反刍前犊牛进行了一项研究，以确定在消除行为模式引起的变化后，门静脉引流内脏、肝脏和后躯对总能量消耗昼夜变化的贡献。采用间接测热法和体内动静脉技术。进食后站立时间较长（P < 0.01），夜间较短（P < 0.01）。这些变化与进食后立即站立时较高（P < 0.01）的能量消耗以及夜间较低（P < 0.01）的能量消耗有关。消除这些行为影响后，躺卧犊牛的总能量消耗在早晚餐之间保持稳定，晚餐后6小时增加11.5%并保持在较高水平，夜间达到最低值。门静脉引流内脏和肝脏分别对始终站立的犊牛计算出的昼夜变化贡献了32.8%至53.7%和29.1%至32.2%。内脏组织能量消耗的变化是由血流量和氧气提取率的综合变化引起的。后躯的贡献无法明确确定。总体而言，门静脉引流内脏、肝脏和后躯分别对站立犊牛的总能量消耗贡献了17.2%、12.8%和18.0%。它们各自的体内代谢活动平均为每克新鲜组织每分钟消耗1.08、2.10和0.25微摩尔氧气。
