Hoffman R M, Hess T M, Williams C A, Kronfeld D S, Griewe-Crandell K M, Waldron J E, Graham-Thiers P M, Gay L S, Splan R K, Saker K E, Harris P A
Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061-0306, USA.
Equine Vet J Suppl. 2002 Sep(34):39-43. doi: 10.1111/j.2042-3306.2002.tb05389.x.
To test the hypothesis that endurance performance may be related quantitatively to changes in blood, we measured selected blood variables then determined their reference ranges and associations with speed during an 80 km race. The plan had 46 horses in a 2 x 2 factorial design testing a potassium-free electrolyte mix and a vitamin supplement. Blood samples were collected before the race, at 21, 37, 56 and 80 km, and 20 min after finishing, for assay of haematocrit, plasma pH, pO2, pCO2, [Na+], [K+], [Ca++], [Mg++], [Cl-], lactate, glucose, urea, cortisol, alpha-tocopherol, ascorbate, creatine kinase, aspartate amino transferase, lipid hydroperoxides, total protein, albumin and creatinine, and erythrocyte glutathione and glutathione peroxidase. Data from 34 finishers were analysed statistically. Reference ranges for resting and running horses were wide and overlapping and, therefore, limiting with respect to evaluation of individual horses. Speed correlations were most repeatable, with variables reflecting blood oxygen transport (enabling exercise), acidity and electrolytes (limiting exercise) and total protein (enabling then, perhaps, limiting). Stepwise regressions also included plasma urea concentration (limiting). The association of speed with less plasma acidity and urea suggests the potential for fat adaptation and protein restriction in endurance horses, as found previously in Arabians performing repeated sprints. Conditioning horses fed fat-fortified and protein-restricted diets may not only improve performance but also avoid grain-associated disorders.
为了验证耐力表现可能与血液变化存在定量关系这一假设，我们测量了选定的血液变量，然后确定了它们的参考范围以及在一场80公里比赛中与速度的关联。该计划采用2×2析因设计，有46匹马，测试无钾电解质混合物和一种维生素补充剂。在比赛前、21公里、37公里、56公里、80公里处以及结束后20分钟采集血样，用于检测血细胞比容、血浆pH值、pO2、pCO2、[Na+]、[K+]、[Ca++]、[Mg++]、[Cl-]、乳酸、葡萄糖、尿素、皮质醇、α-生育酚、抗坏血酸、肌酸激酶、天冬氨酸氨基转移酶、脂质氢过氧化物、总蛋白、白蛋白和肌酐，以及红细胞谷胱甘肽和谷胱甘肽过氧化物酶。对34匹完赛马匹的数据进行了统计分析。静息和奔跑马匹的参考范围较宽且相互重叠，因此在评估个体马匹时具有局限性。速度相关性最具重复性，相关变量反映了血液氧运输（支持运动）、酸度和电解质（限制运动）以及总蛋白（起初支持运动，或许随后限制运动）。逐步回归分析还纳入了血浆尿素浓度（限制因素）。速度与较低的血浆酸度和尿素之间的关联表明耐力马匹存在脂肪适应和蛋白质限制的潜力，这与之前对进行重复冲刺的阿拉伯马的研究结果一致。给马匹提供强化脂肪和限制蛋白质的日粮进行训练，不仅可以提高表现，还能避免与谷物相关的疾病。
