Principal component analysis of cephalic morphology to classify some Pyrenean cattle.

Abstract

Seven morphostructural traits namely head, face and skull widths and lengths and head depth of 300 cows belonging to seven different French and Spanish breeds were measured. The investigation aimed at grouping these cattle breeds according to their head conformation using principal component analysis. From the normalized varimax rotation, two principal components that accounted for 68.1 percent of the total variance were extracted. The first principal component, termed viscerocranium length component, had its loadings for face and head lengths and explained 49.9 percent of the generalized variance. Skull and head widths determined the second principal component, which contributed to 19.2 percent of the variance, and could be termed the component of the neurocranium width. There is a good deal of overlap between breeds although the Avileña breed shows an increasingly longer built skull in terms of face and skull lengths. The Blanca del Pallars breed appears significantly separated from alpine breeds but closely related to Gascon.