摘要:The purpose of this investigation was to evaluate the clinical usefulness of the total radiographic bone aluminum equivalency (RBAE) method for the measurement of bone mineral content (BMC) in the third metacarpal bone (McIII) of the young Thoroughbred by examining: a) changes in BMC and bone metabolism marker levels in young Thoroughbreds being trained in the growth period; b) correlation of BMC and bone metabolism marker levels; and c) relationships of BMC and bone metabolism marker levels with the state of occurrence of bone disorders. The total RBAE method by the ortho system was chosen for this study. Ninety-one 2-year-old Thoroughbreds that showed no abnormalities on physical examination before the study were evaluated for BMC, and 39 were selected at random for evaluation of the bone metabolism marker levels. BMC of the normal horses showed no change between Days 0 and 90 of the study, but significantly increased on Day 180 (p<0.01). BMC showed no correlations with bone metabolism markers. In addition, there was a high incidence of bone disorders in Days 0-90 of the study when BMC did not change though training increased. These results suggest that the measurement of BMC by the total RBAE method in young Thoroughbreds is useful for providing information about skeletal development, and also for obtaining information on the predisposing period for bone disorders.