Morphology and structural characteristic of the thoracic vertebrae in the zebu (Bos indicus).

The thoracic vertebrae and the course of the ligamentum nuchae were investigated in the East African zebu (Bos indicus) from birth to the age of four years. The results were compared with the findings in 28 specimens of Bos taurus aged 1-4 years. In Bos indicus, at all ages, the apices of the spinous processes of the 7th to 13th thoracic vertebrae are forked. The terminal arms are covered with cartilage, which provides attachment for the funicular part of the ligamentum nuchae. The tips of the spinous processes of the 3rd, 4th and 6th thoracic vertebrae which point dorsad and slightly caudad, are bordered by the two lateral portions of the funicular ligamentum nuchae. At its dorsal insertion, the nuchal ligament lies between the terminal branches, thereby creating a concavity. In Bos taurus, however, there is a convexity, because the spinous processes are not forked. Towards the lumbar spine, the spinous processes become shorter and flat-sided.