Parés-Casanova Pere M, Castel-Mas Laura, Jones-Capdevila Kirian N
Department of Animal Science, ETSEA, University of Lleida, Av. Rovira Roure 191, 25198 Lleida, Catalonia, Spain.
Vet Sci. 2020 Jul 2;7(3):83. doi: 10.3390/vetsci7030083.
Based on the anatomical premise that, in bovines, the medial (inner) hoof is larger than the lateral (outer) one in the forelimb, we hypothesized that this implies a phalangeal form difference. To test this hypothesis, asymmetries of the forelimb acropodia (phalangeal series) were studied on calves belonging to the Brown Pyrenean breed, a meat breed managed under extensive conditions in NE Spain. Dorso-palmar radiographs were obtained for each acropodium in a sample of 17 paired left and right forelimbs. Size and shape were analysed by means of geometric morphometrics on medial and lateral acropodial series (III and IV series respectively) for each left and right limb. Shape coordinates were computed by Generalized Procrustes Analysis. Medial and lateral acropodial series appeared similar in size, but their shape expressed an especially high directional asymmetry, with distal phalanges (pedal bones) being abaxially (outwards) oriented. Such morphological observations may be an important reconsideration of "normal" radiographic acropodial symmetry evaluation. This can be explained not only by an unevenly distributed ground reaction force between acropodial series, but also between right and left limbs, making medial and lateral hoof surfaces differently prone to overloading and, accordingly, to injuries to the limb.
基于牛前肢内侧（内）蹄大于外侧（外）蹄这一解剖学前提，我们推测这意味着趾骨形态存在差异。为验证这一假设，我们对西班牙东北部粗放养殖的肉牛品种比利牛斯褐牛犊牛的前肢肢端（趾骨系列）不对称性进行了研究。对17对左右前肢样本中的每个肢端进行了背掌位X线摄影。通过几何形态测量学方法，对每个左右肢体的内侧和外侧肢端系列（分别为III和IV系列）的大小和形状进行了分析。通过广义普氏分析计算形状坐标。内侧和外侧肢端系列大小相似，但其形状表现出特别高的方向不对称性，远端趾骨（蹄骨）向轴外（向外）定向。这种形态学观察结果可能是对“正常”X线肢端对称性评估的重要重新考量。这不仅可以通过肢端系列之间，而且可以通过左右肢体之间地面反作用力分布不均来解释，这使得内侧和外侧蹄面承受过载的倾向不同，相应地也更容易导致肢体受伤。
