Department of Clinical Sciences, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Department of Clinical Sciences, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Poult Sci. 2024 Oct;103(10):104127. doi: 10.1016/j.psj.2024.104127. Epub 2024 Jul 29.
Femoral head necrosis (FHN) in broilers is a common leg disorder in intensive poultry farming, giving rise to poor animal health and welfare. Abnormal mechanical stress in the hip joint is a risk factor for FHN, and articular cartilage is attracting increasing attention as a cushion and lubrication structure for the joint. In the present study, broilers aged 3 to 4 wk with FHN were divided into femoral head separation (FHS) and femoral head separation with growth plate lacerations (FHSL) groups, with normal broilers as control. The features of the hip joint, bone, and cartilage were assessed in FHN progression using devices including computed tomography (CT), atomic force microscope (AFM), and transmission electron microscopy (TEM). Broilers with FHN demonstrated decreased bone mechanical properties, narrow joint space, and thickened femoral head stellate structures. Notably, abnormal cartilage morphology was observed in FHN-affected broilers, characterized by increased cartilage thickness and rough cartilage surfaces. In addition, as FHN developed, cartilage surface friction and friction coefficient dramatically increased, while cartilage modulus and stiffness decreased. The ultramicro-damage occurred in chondrocytes and the extracellular matrix (ECM) of cartilage. Cell disintegration, abnormal mitochondrial accumulation, and oxidative stress damage were observed in chondrocytes. A notable decline in cartilage collagen content was observed in ECM during the initial stages of FHN, accompanied by a pronounced reduction in collagen fiber diameter and proteoglycan content as FHN progressed. Furthermore, the noticeable loosening of the collagen fiber structure and the appearance of type I collagen were noted in cartilage. In conclusion, there was a progressive decrease in bone quality and multifaceted damage of cartilage in the femoral head, which was closely linked to the severity of FHN in broilers.
肉鸡股骨头坏死（FHN）是集约化家禽养殖中一种常见的腿部疾病，导致动物健康和福利状况不佳。髋关节的异常机械应力是 FHN 的一个风险因素，关节软骨作为关节的缓冲和润滑结构越来越受到关注。在本研究中，将 3 至 4 周龄患有 FHN 的肉鸡分为股骨头分离（FHS）和股骨头分离伴生长板撕裂（FHSL）组，以正常肉鸡作为对照。使用包括计算机断层扫描（CT）、原子力显微镜（AFM）和透射电子显微镜（TEM）在内的设备评估 FHN 进展过程中髋关节、骨骼和软骨的特征。患有 FHN 的肉鸡表现出骨力学性能下降、关节间隙变窄和股骨头星状结构增厚。值得注意的是，患有 FHN 的肉鸡出现了异常的软骨形态，表现为软骨厚度增加和软骨表面粗糙。此外，随着 FHN 的发展，软骨表面摩擦和摩擦系数显著增加，而软骨模量和刚度降低。软骨细胞和细胞外基质（ECM）发生超微损伤。在软骨细胞中观察到细胞解体、异常线粒体积累和氧化应激损伤。在 FHN 的初始阶段，ECM 中观察到软骨胶原含量显著下降，伴随着胶原纤维直径和蛋白聚糖含量的明显减少，随着 FHN 的进展而减少。此外，在软骨中还观察到胶原纤维结构明显松弛和 I 型胶原出现。总之，在股骨头中存在骨质量逐渐下降和软骨多方面损伤的现象，这与肉鸡 FHN 的严重程度密切相关。
