In breeding programmes, the genetic selection process is based on the prediction of animal breeding values, and its results may vary according to the employed selection method. The current study developed an economic selection index for animals of the Angus breed; performed cluster analyses using the breeding values in order to evaluate the genetic profile of the animals candidates to selection, and compared the obtained results between the economic selection index and the cluster analyses. The evaluated traits included weaning weight, 18-month weight, scrotal circumference, fat thickness and ribeye area. Economic values were obtained using bioeconomic modelling, simulating a complete cycle production system of beef cattle breeds in Brazil, and the selection objective were the weaning rate and slaughter weight. The chosen selection index was composed of all of the traits used as selection criteria for the simulated production system. During the cluster analyses, the population was divided into two to four groups, in which the groupings containing potential animals were assessed. The animals of the grouping which was used for comparison with the selection index were identified, and most of the bulls that were included in the index were among the best in the analysed group. These results suggest that the cluster analyses can be used as a tool for the selection of animals to be used as parents for future generations.

中文翻译：

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安格斯牛的多性状选择指数和聚类分析

在育种计划中，遗传选择过程基于对动物育种价值的预测，其结果可能会根据所采用的选择方法而有所不同。目前的研究为安格斯品种的动物制定了经济选择指数；使用育种值进行聚类分析以评估候选动物的遗传特征进行选择，并比较经济选择指数和聚类分析之间获得的结果。评估的性状包括断奶体重、18个月体重、阴囊周长、脂肪厚度和肋眼面积。通过生物经济模型获得经济价值，模拟巴西肉牛品种的完整循环生产系统，选择目标是断奶率和屠宰重量。选择的选择指数由用作模拟生产系统选择标准的所有性状组成。在聚类分析期间，种群被分为两到四组，其中包含潜在动物的分组进行了评估。确定了用于与选择指数进行比较的分组动物，该指数中的大多数公牛在分析组中均名列前茅。这些结果表明，聚类分析可以用作选择动物作为后代父母的工具。确定了用于与选择指数进行比较的分组动物，该指数中的大多数公牛在分析组中均名列前茅。这些结果表明，聚类分析可以用作选择动物作为后代父母的工具。确定了用于与选择指数进行比较的分组动物，该指数中的大多数公牛在分析组中均名列前茅。这些结果表明，聚类分析可以用作选择动物作为后代父母的工具。