The time of appearance of Ossiffication centres in the Peppin-type Merino.

Abstract

The time of appearance of appendicular ossification centres in the Peppin-type Merino foetus has been established using radiological methods on 68 foetuses of known age. A standard of reference of the aging process or maturation process of bone has been drawn up using the number of ossification centres present and the contour changes of certain of these centres as a yardstick. Osseous maturation is thus given a numerical score. Measurements of tibial and body length have also been taken. The entire data (the four variables being age, body length, tibial length, and osseous maturation score) have been subjected to a correlation analysis. Very high correlation coefficients were obtained, ranging from +0.98 to +0.99. It is thus clearly seen from the results of the analysis that body length, tibial length, or osseous maturation measurements are of equal value in assessing the age of the foetus. Furthermore, because of these high correlations a combined regression equation would be pointless.