Morphometric measurements and animal-performance indices in a study of racial forms of Brazilian Sport Horses undergoing training for eventing

ABSTRACT This study aimed to evaluate, in a practical manner, the use of linear and angular measurements and different animal-performance indices in a study on the breed-specific conformation of Brazilian Sport Horses training for eventing. These data can form the basis for the development of future studies based on the parameters evaluated and the calculations made. Seventeen Brazilian Sport Horses training for eventing were selected. Morphometric evaluations were made of all animals using linear and angular measurements. The linear measurements were withers, croup, and barrel heights; body, croup, shoulder, neck, and head lengths; head, chest, and hip widths; distance from the elbow to the ground and from the sternum to the ground (empty substernal); and thorax, forearm, knee, fetlock, and fore cannon girths. The angular measurements were shoulder-ground, shoulder-humerus, humerus-radius, metacarpus-phalanx, coxae-ground, coxae-femur, femur-tibia, and tibia-metatarsus angles. Thirteen animal-performance indices were calculated to have a better understanding of the conformation of the animals and their proportions: the relationship between the withers and croup heights, chest index, dactyl-thoracic index, estimated weight, body index, thoracic index, conformation index, load index 1, load index 2, relative body index, compactness index 1, compactness index 2, and meloscopic index. Brazilian Sport Horses in eventing training were within the expected conformation for an athletic horse, but the animal-performance indices differed among them because they are heterogeneous horses resulting from crossing among various different breeds. The use of linear and angular measurements allows the correct characterization of racial forms of Brazilian Sport Horses undergoing training for eventing. Animal-performance indices can be useful in a study of a breed-specific conformation of athletic horses.

摘要
本研究旨在以实用化路径，评估线性与角度测量手段及不同动物性能指数（animal-performance indices）在针对马术三项赛训练用巴西运动马品种特异性体型结构的研究中的应用价值。本研究所得数据可作为后续基于本次评估参数与计算方法开展相关研究的基础。本研究共遴选17匹参与马术三项赛训练的巴西运动马作为受试对象，对所有受试动物开展形态测量学评估，测量内容涵盖线性与角度参数两类。其中线性测量指标包括：鬐甲高、尻高与躯干高；体长、尻长、肩长、颈长及头长；头宽、胸宽及髋宽；肘离地距离与胸骨离地距离（空腹胸骨距）；以及胸廓、前臂、膝部、球节与前掌骨围度。角度测量指标包括：肩-地面角、肩-肱骨角、肱骨-桡骨角、掌骨-指骨角、髋-地面角、髋-股骨角、股骨-胫骨角及胫骨-跖骨角。为更全面地了解受试动物的体型结构及其比例特征，研究人员共计算了13项动物性能指数：鬐甲高与尻高之比、胸廓指数、指胸指数、估测体重、体指数、胸腔指数、体况指数、负重指数1、负重指数2、相对体指数、紧凑度指数1、紧凑度指数2及目测体型指数（meloscopic index）。参与马术三项赛训练的巴西运动马体型结构符合竞技马的预期标准，但不同个体的动物性能指数存在差异，这是由于该品种为多品种杂交培育的异质性马群。通过线性与角度测量手段，可准确表征参与马术三项赛训练的巴西运动马的品种特异性体型特征，动物性能指数可有效应用于竞技马的品种特异性体型结构研究。