A radiological investigation of the sternum of the sheep demonstrated
distinct growth phases. Forty Merino sheep of mixed breeds were distri
buted into 4 age groups of 0, 45, 105 and 270 days. Each animal was ra
diographed in sternal and lateral recumbency. Measurements were made f
rom the radiographs. The sternebra are rectangular in newborn and beco
me concave in adult. The curvature of the sternum is 16 to 17-degrees
at day 0 and 27-28-degrees at day 270. The nucleus of ossification was
seen in all sternebrae at 45 days of age, they were present only in t
he most caudal sternebrae at 105 days.