Yamada Masayoshi, Chen Chongxiao, Sugiyama Toshie, Kim Woo Kyun
Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan.
Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC 27695, USA.
Animals (Basel). 2021 Feb 22;11(2):570. doi: 10.3390/ani11020570.
Changes in medullary and cortical bone structure with age remain unclear. Twenty Hy-Line W36 hens, 25 or 52 weeks of age, were euthanized, and both tibiae were collected when an egg was present in the magnum. Serial cross sections of the tibiae were stained with Alcian blue. The bones were scanned using micro-computed tomography. Trabecular width (Tb.Wi) was significantly higher ( < 0.05) in 25-week-old hens, whereas medullary bone tissue volume (TV) was significantly higher ( < 0.01) in 52-week-old hens. 25-week-old hens had significantly higher ( < 0.01) bone volume fraction (BVF = calcified tissue / TV). Moreover, the cortical bone parameters were significantly higher (TV and bone mineral content (BMC) at < 0.05, and bone volume (BV) and BVF at < 0.01) in younger hens. Open porosity and total porosity, which indicate less density, were significantly higher ( < 0.01) in older hens. Older hens showed significantly higher ( < 0.01) tibial diaphysis TV than younger hens. Younger hens had significantly higher ( < 0.01) BV, BVF and bone mineral density (BMD) of the tibial diaphysis. These findings reveal that reductions in medullary bone quality might be associated with age-related low estrogen levels and stimulation of osteoclastic bone resorption by parathyroid hormone. Cortical bone quality decreased with enlargement of the Haversian canals and loss of volume, with a longer egg-laying period leading to osteoporosis.
随着年龄增长，髓质骨和皮质骨结构的变化尚不清楚。选取20只25周龄或52周龄的海兰W36母鸡，在其输卵管膨大部有蛋时实施安乐死并采集双侧胫骨。胫骨连续横断面用阿尔新蓝染色。使用微型计算机断层扫描对骨骼进行扫描。25周龄母鸡的小梁宽度（Tb.Wi）显著更高（P<0.05），而52周龄母鸡的髓质骨组织体积（TV）显著更高（P<0.01）。25周龄母鸡的骨体积分数（BVF = 钙化组织 / TV）显著更高（P<0.01）。此外，年轻母鸡的皮质骨参数显著更高（TV和骨矿物质含量（BMC），P<0.05；骨体积（BV）和BVF，P<0.01）。表明密度较低的开放孔隙率和总孔隙率在老年母鸡中显著更高（P<0.01）。老年母鸡的胫骨干TV显著高于年轻母鸡（P<0.01）。年轻母鸡胫骨干的BV、BVF和骨矿物质密度（BMD）显著更高（P<0.01）。这些发现表明，髓质骨质量的下降可能与年龄相关的低雌激素水平以及甲状旁腺激素对破骨细胞骨吸收的刺激有关。皮质骨质量随着哈弗斯管的扩大和体积的减少而下降，产蛋期延长会导致骨质疏松。
