Caracterização morfométrica de equinos da raça Quarto de Milha utilizados em vaquejada

Abstract

The horses serve various purposes, and, for each one, are needed animals of various kinds, ie, with different and specific characteristics related to conformation, fitness, temperament, training and performance. The morphometric analysis is widely used in the choice of horses, especially for sports activities, as the body shape defines the limits and the animals' ability to perform movimentos. This work aimed to characterize the Quarter horse used in 'vaquejada' as for their linear and angular morphometric measurements, evaluate the multivariate analysis and proportions. We measured 98 animals, 69 males and 29 females. The information collected was 27 linear and 9 angular measurements. The results were compared by SNK test at 5% probability. Significant difference was found (P <0.05) between the sexes only for linear and angular measurements of the back-loin length, the perimeter of the posterior shin and scapular-humeral angle. Females had a higher back-loin length (50,64 and 47,31cm) and larger scapular-humeral angle (91.31 and 87.99 degrees) while males had bigger perimeter of shin (20.26 and 19.64 cm ). In the evaluation of linear and angular measurements of males and females were took eight and four, and six and three principal components, respectively, to account for a minimum percentage of 66.94% and 64.71% and 67.56% and 60.14% existing total variation. It was found in Quarter Horse the proportions for the variables of height at withers was higher than that one laid down by Lesbre (1920) while for hip height showed up with higher proportions (2.71). The Quarter Horse used in 'vaquejadas' have linear and angular measurements similar between the sexes, except for the length of the back-loin, the perimeter of shin and scapular-humeral angle. The principal components analysis was efficient to reduce the number of linear and angular measurements for morphometric evaluation of females and males Quarter Horses 'vaquejada'. Factor analysis was also efficient to group the linear and angular measures improving view of the factors that stood out over the others. The Quarter Horse has genetically different biotype in their linear measures and their proportions to the values suggested by Lesbre (1920).