Table 1.
Morphometric measurements (mean ± SD) of horse (n = 12) and donkey (n = 14) skulls. P values were calculated using a General Linear Model, with a value <0.05 considered significantly different.
| Variable | Horse | Donkey | p-Value |
|---|---|---|---|
| Mean | Mean | ||
| Head weight (kg) | 22.5 ± 4.9 | 13.6 ± 3.7 | <0.0001 * |
| Skull length (cm) | 53.6 ± 2.6 | 46.6 ± 5.0 | 0.0080 * |
| Cranial length (cm) | 23.6 ± 1.4 | 20.4 ± 2.7 | 0.0002 * |
| Nasal length (cm) | 30.4 ± 3.9 | 27.5 ± 3.1 | 0.1919 |
| Zygomatic width (cm) | 22.6 ± 1.8 | 21.9 ± 2.2 | 0.0776 |
| Cranial width (cm) | 19.0 ± 0.8 | 16.3 ± 2.4 | <0.0001 * |
| Mandibular depth (cm) | 27.2 ± 1.1 | 24.5 ± 2.4 | 0.0019 * |
| Skull index | 42.2 ± 3.2 | 46.2 ± 3.4 | 0.0025 * |
| Cranial index | 80.9 ± 6.2 | 77.2 ± 9.1 | 0.1399 |
| Nasal index | 76.0 ± 14.5 | 79.6 ± 7.5 | 0.6600 |
| Mandibular index | 50.8 ± 2.6 | 52.2 ± 5.2 | 0.5791 |
| Cranial profile index | 8.8 ± 1.0 | 7.6 ± 1.2 | 0.0335 * |
| Nasal profile index | 9.1 ± 2.8 | 7.3 ± 0.8 | 0.8359 |
| Olfactory bulb area (cm2) | 2.3 ± 1.3 | 1.98 ± 1.3 | 0.0478 * |
| Olfactory bulb pitch (°) | 66.0 ± 11.8 | 56.6 ± 1318 | 0.0163 * |
| Brain pitch (°) | 18.3 ± 45.7 | 16.7 ± 37.8 | 0.4338 |
| Whorl location (cm) | 0.1 ± 1.5 | 8.0 ± 6.5 | 0.0001 * |
* denotes the statistical difference between horses and donkeys at the level of p < 0.05.