Factors affecting the performance of Pantaneiro horses

ABSTRACT This study aimed to assess the physical performance of Pantaneiro horses with and without equine infectious anemia (EIA) under functional conditions of cattle management. The horses were subjected to a performance test and split into two groups according to a completely randomized design: animals were chosen from populations testing positive and negative for EIA. Performance was measured as a function of a data envelopment analysis (DEA) model considering four outputs and one unitary input. The output measures were the distance achieved in the performance test, hematocrit as a weighted average over the test duration, respiratory rate as weighted average over the test duration, and the level of lactic acid at the test termination. Weights for the hematocrit and the respiratory rate output variables were determined by means of factor analysis. The performance score was a weighted average of the output variables with the weights defined by the averages of the optimum individual multipliers in the DEA analysis. Contextual variables of interest were age, horse weight, room temperature, and corporal temperature. Only groups and room temperature were statistically significant effects, as indicated by a bootstrap analysis. The performance of group positive for EIA is significantly lower than that of the group negative for EIA and room temperature has a negative effect.

摘要
本研究旨在评估处于肉牛管理作业工况下，马传染性贫血（Equine Infectious Anemia, EIA）阳性与阴性的潘塔内罗马的体能表现。试验采用完全随机设计，将受试马匹按EIA检测结果分为两组并开展性能测试。本研究采用数据包络分析（Data Envelopment Analysis, DEA）模型构建性能评价体系，该体系包含4项产出指标与1项单一投入指标。其中产出指标分别为性能测试的行进距离、测试全程加权平均红细胞压积、测试全程加权平均呼吸频率，以及测试结束时的乳酸水平。红细胞压积与呼吸频率两项产出变量的权重通过因子分析确定。性能评分为各产出变量的加权平均值，其权重由DEA分析中最优个体乘数的均值确定。本研究关注的协变量包括年龄、马匹体重、环境温度与直肠体温。自助法分析结果显示，仅分组与环境温度存在统计学显著效应：EIA阳性组的体能表现显著低于阴性组，且环境温度对体能表现存在负向影响。