RADIOGRAPHICAL EVALUATION OF BONE MATURATION IN JAPANESE BLACK BEEF-CATTLE

Epiphyseal ossification in the radius, ulna, metacarpus, proximal phal anx and tuber calcaneus was examined radiographically in Japanese Blac k beef cattle. The grade of standard ossification was assessed monthly for each epiphysis. Bone maturations could be divided into 8 grades f or the distal radius and distal ulna, 7 grades for the distal metacarp us, 5 grades for the proximal phalanx, and 8 grades for the tuber calc aneus, respectively. The closure of the epiphyseal line completed at t he earliest (12-14 months of age) on the proximal phalanx, and at the latest (35-37 months of age) on the distal ulna. Changes in gradings w ere steep at 0 to 5 months of age bur became almost constant after 10 months of age in all the epiphyses. There were no significant differen ces in bone maturation between the cattle with different sex and breed ing conditions.