The variability of cranial morphology in modern horses.

Horses bred nowadays are characterized by high variability of the body build. The variability concerns exterior features and skeleton features. From among the skeleton parts the skull is an element influenced by selection and environmental adaptation. The aim of these investigations was to find whether cranial traits exhibit variability in relation to the body build of horses. To do this, metric parameters of skulls of 43 horses used in the investigations were analysed with various statistical techniques. On the basis of ANOVA, Principal Components Analysis and Canonical Discriminant Analysis it was found that horses of various constitutional types exhibit differences in cranial morphology. Warm blood horses of the respiratory constitutional type have more complex nasal cavity from horses of heavier body build. A meaningful effect on craniometric variability was observed in the length and breadth of the viscerocranium. Also the height of the viscerocranium--a cranial feature of the respiratory tract, showed a high discriminating power.