Biometric Studies on the Type of the Dairy Cow

(1) Ten physical characters of 487 dairy cws especially, Holstein cows and its hybrids over two aged or more in Nara, Iapan, were biometrically studied for the purpose of improving them. The characters of the body were measured and various biometric constants, namely, the mean value, the standard deviation and the variation coefficient, were caluculated and the variation curve was found to be agresd with the normal curve. (2) The existence of positive correlations were showed through the measurment of the nine parts of physical characters and then the regression coefficient and the regression equation were caluculated. Thus the normal types were decided in the usual way. (3) Those dairy cows are fitted into the normal type showed 11.9% of the whole. (4) Comparing the values obtained by the writer and TAKEUCHI (1951) with by SASAKI (1927), a significant difference was found out in the most part of ten physical characters. From these results it may be concluded that the size of dairy cow in Iapan has lately decreased under the feeding, management and the like