Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
Arch Anim Nutr. 2021 Dec;75(6):489-509. doi: 10.1080/1745039X.2021.2015986. Epub 2022 Mar 1.
The oral C-bicarbonate technique (oCBT) can be used for short-term measurements of CO production (CO) and energy expenditure (EEx). The method relies on appropriate estimates for the respiratory quotient (RQ) and recovery factor (RF) of C. Four Retriever dogs were included in four experiments to validate the oCBT against indirect calorimetry (IC), and determine RQ and RF; : feeding different protein:fat:carbohydrate ratios [in % of metabolisable energy]: 25:33:42 in a maintenance (Mnt.) diet; 38:26:36 in a high-protein high-fibre (H) diet and 27:56:17 in a high-fat (H) diet, simultaneously with start of measurements (T); : the Mnt. diet at T or 4 h postprandial (T); : T at different ambient temperatures, 22°C and 15°C; : T after 1 h physical activity. The CO and EEx were determined from the respiration chamber measurements made simultaneously with IC and the oCBT (oCBT), and in and , also on two consecutive days using oCBT with collection of breath into breath bags (oCBT). The RQ values obtained at T reflected dietary compositions, with the highest least square mean (LSM) of 0.954 for the Mnt. diet, 0.905 for the H and 0.877 for the H diet ( < 0.05). An increased interval between meal and measurement period decreased RQ significantly ( < 0.05) in , LSM being 0.954 at T and 0.909 at T. Ambient temperature ( and physical activity () did not influence postprandial RQ. The RF values were not significantly affected by diet (. Measurements starting at T () resulted in higher ( < 0.05) RF values than at T (LSM = 0.971 and 0.836, respectively). The ambient temperatures ( did not influence postprandial RF. However, when dogs were physically active prior to measurements (), RF values (LSM = 1.019) were higher ( < 0.05) than when resting only (LSM = 0.836). Calculations based on RQ and RF determined in each experiment resulted in CO and EEx values which were not different regardless of method used, except for where EEx-values [kJ · kg BW · d] were higher ( < 0.05) when measured with oCBT (460) than by IC (421) and oCBT (420). Provided accurate RQ and RF values, the oCBT can be used as an independent and minimally invasive research tool to determine EEx in dogs under carefully standardised conditions.
口腔 C-碳酸氢盐技术 (oCBT) 可用于短期测量 CO 生成 (CO) 和能量消耗 (EEx)。该方法依赖于对 C 的呼吸商 (RQ) 和恢复因子 (RF) 的适当估计。在四项实验中纳入了四只可卡犬，以间接测热法 (IC) 验证 oCBT，并确定 RQ 和 RF；：以不同的蛋白质：脂肪：碳水化合物比例[占代谢能的%]喂食 25:33:42 的维持 (Mnt.) 饮食；38:26:36 的高蛋白高纤维 (H) 饮食和 27:56:17 的高脂肪 (H) 饮食，同时开始测量 (T)；：T 或进食后 4 小时 (T) 时的 Mnt. 饮食；：T 时不同的环境温度，22°C 和 15°C；：T 后 1 小时体力活动。从与 IC 和 oCBT（oCBT）同时进行的呼吸室测量中确定 CO 和 EEx，并且在 和 中，还使用收集呼吸袋的 oCBT（oCBT）在两天内连续进行测量。在 T 时获得的 RQ 值反映了饮食组成，Mnt. 饮食的最低二乘平均值 (LSM) 最高为 0.954，H 饮食为 0.905，H 饮食为 0.877（<0.05）。进食和测量间隔时间增加，RQ 显著降低（<0.05），T 时的 LSM 为 0.954，T 时为 0.909。环境温度（和体力活动（）不影响餐后 RQ。饮食对 RF 值没有显著影响（）。测量开始于 T（）时的 RF 值（LSM=0.971 和 0.836）高于 T（LSM=0.909）。环境温度（）不影响餐后 RF。然而，当狗在测量前进行体力活动时（），RF 值（LSM=1.019）较高（<0.05），而仅休息时（LSM=0.836）则较低。根据每个实验中确定的 RQ 和 RF 进行计算，结果表明 CO 和 EEx 值不因方法而异，除了在 中，用 oCBT（460）测量的 EEx 值[kJ·kgBW·d]比 IC（421）和 oCBT（420）高（<0.05）。只要提供准确的 RQ 和 RF 值，oCBT 就可以作为一种独立的、微创的研究工具，在精心标准化的条件下确定狗的 EEx。
