The effect of year and season of birth, sex, sire, and breeder on ossification of the distal epiphyseal cartilage of the radial bone in Thoroughbred horses

Abstract

The aim of this study was to evaluate the effect of specific factors on ossification of the distal epiphyseal cartilage of the radial bone in Thoroughbred horses. The study was carried out on 452 Thoroughbred horses, two years old, that were under race training. X-ray tests were conducted and interpreted every month starting at the 18th month of life and continuing until ossification of the distal epiphyseal cartilage of the radial bone occurred. In the statistical model, the year of birth, sex, birth season, sire, and breeder were treated as constant effects. Horses that were born in the spring season were characterized by a shorter time until the closure of the distal radial epiphyseal cartilage in comparison to horses born in the winter season; the difference between these times was found to be highly significant. Furthermore, it was shown that the ossification time of cartilage was also significantly influenced by the year of birth, the sire, and the breeder. Knowledge and monitoring of factors affecting the rate of somatic maturity in Thoroughbred horses can be useful in breeding and veterinary practices. This fact, in conjunction with the analysis of somatotrophic processes, will provide a basis for improving the feeding, training, and management system of Thoroughbred horses as well as aiding in the early diagnosis, treatment, or prevention of various diseases associated with intensive growth in the early period of life.