Departamento de Ciencias Agroforestales, ETSIA, Universidad de Sevilla, Sevilla, Spain.
J Anim Breed Genet. 2013 Jun;130(3):190-8. doi: 10.1111/jbg.12001. Epub 2012 Sep 18.
The purpose of this study was to study phenotypic plasticity ability for Show Jumping performance in horses according to age differences. For this study, 11 352 participations, belonging to 1085 horses grouped by age (4-, 5- or 6-year olds), were analysed. repeatability animal models (RAM) and multiple trait animal models (MTAM) were compared. RAM assumed the same covariance components for all age groups, whereas MTAM considered the results of every animal at every age group as different (but correlated) traits. The age, sex, starting order and training level were included as fixed effects. The random effects were the animal, the individual permanent environment, the competition and the rider. Six models were compared, and the rider-horse interaction was added as a random effect; furthermore, heterogeneous residual variance was taken into consideration only for MTAM. The study of the genetic correlations between age groups highlighted the presence of an age-genotype interaction and, therefore, an underlying environmental effect. This study may allow us to select horses with a plastic response, which show either a gradual response or a precocious response and thus gain or lose genetic potential with age, respectively.
本研究旨在根据年龄差异研究跳跃表演的表型可塑性能力。为此，对 11352 名参与者（属于 1085 匹马，按年龄分组：4 岁、5 岁或 6 岁）进行了分析。重复动物模型（RAM）和多性状动物模型（MTAM）进行了比较。RAM 假设所有年龄组的协方差组件相同，而 MTAM 则将每个动物在每个年龄组的结果视为不同（但相关）的性状。年龄、性别、起始顺序和训练水平被纳入固定效应。随机效应是动物、个体永久环境、比赛和骑手。比较了 6 个模型，将骑手-马的相互作用作为随机效应添加；此外，仅对 MTAM 考虑了异质残差方差。对年龄组之间遗传相关性的研究强调了存在年龄-基因型相互作用，因此存在潜在的环境效应。本研究可以使我们选择具有可塑性反应的马，这些马表现出逐渐的反应或早熟的反应，因此随着年龄的增长分别获得或失去遗传潜力。
