The purpose of this study was to evaluate the relationship between adaptive and productive performance and determine which characteristics related to adaptation could be included as criteria for the selection of Brahman bulls managed in a tropical region. Fifty Brahman bulls were evaluated in relation to productive performance and adaptive capacity to a hot environment. The animals were grouped according to the following characteristics: Respiratory rate (RR), Sweating rate (SR) and coat traits. Three clusters were formed with these different characteristics related to thermoregulation after that these clusters were compared with productive performance that includes weighing of animals, carcass and scrotal circumference. The high adapted group corresponded to the animals with higher productive performance, with heavier animals in terms of weight at 550 days and carcass weight. The principal components analysis (PCA1) showed that carcass weight (0.95), weight at 550 days (0.92) and gain weight (0.71) were characteristics strongly correlated with the performance of the animals. These sets of characteristics were analyzed together (productive characteristics) in a multiple regression. The animals with better productive performance presented shorter hair, a greater capacity to heat dissipate by sweating and a lower rectal temperature. These characteristics were most suitable to inclusion in the breeding programs, resulting in higher economic gains. It is possible to simultaneously select resistant animals to thermal stress as well as to maintain the productivity of the flocks.

中文翻译：

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婆罗门公牛的表型选择：育种计划的适应性典型化

本研究的目的是评估适应性和生产性能之间的关系，并确定哪些与适应性相关的特征可以作为选择在热带地区管理的婆罗门公牛的标准。评估了 50 头婆罗门公牛的生产性能和对炎热环境的适应能力。根据以下特征将动物分组：呼吸率(RR)、出汗率(SR)和皮毛特征。在将这些集群与包括动物称重、胴体和阴囊周长在内的生产性能进行比较之后，形成了具有与体温调节相关的这些不同特征的三个集群。高适应组对应于生产性能较高的动物，较重的动物在 550 天时的体重和胴体重量。主成分分析 (PCA1) 显示胴体重 (0.95)、550 天体重 (0.92) 和增重 (0.71) 是与动物表现密切相关的特征。这些特征集在多元回归中一起分析（生产特征）。生产性能更好的动物毛发更短，出汗散热能力更强，直肠温度更低。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。主成分分析 (PCA1) 显示胴体重 (0.95)、550 天体重 (0.92) 和增重 (0.71) 是与动物表现密切相关的特征。这些特征集在多元回归中一起分析（生产特征）。生产性能更好的动物毛发更短，出汗散热能力更强，直肠温度更低。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。主成分分析 (PCA1) 显示胴体重 (0.95)、550 天体重 (0.92) 和增重 (0.71) 是与动物表现密切相关的特征。这些特征集在多元回归中一起分析（生产特征）。生产性能更好的动物毛发更短，出汗散热能力更强，直肠温度更低。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。71) 是与动物表现密切相关的特征。这些特征集在多元回归中一起分析（生产特征）。生产性能更好的动物毛发更短，出汗散热能力更强，直肠温度更低。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。71) 是与动物表现密切相关的特征。这些特征集在多元回归中一起分析（生产特征）。生产性能更好的动物毛发更短，出汗散热能力更强，直肠温度更低。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。这些特性最适合纳入育种计划，从而带来更高的经济收益。可以同时选择对热应激具有抗性的动物以及保持鸡群的生产力。