Newbrey J W, Baksi S N, Dhillon A S, Zimmerman N G, Truitt S G, Riedinger R
Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520.
Avian Dis. 1988 Oct-Dec;32(4):704-12.
Vitamin D metabolite levels and tibiotarsal histomorphometric characteristics were determined in 49-day-old male broilers. Valgus-varus bone deformity was present in 5.2% and tibial dyschondroplasia (TD) in 3% of these broilers, which were raised on floor litter under seemingly normal nutritional, space, and lighting conditions. No significant weight differences were observed between normal and lame broilers. The plasma levels of 25-OH-D were the same in lame and normal broilers. However, 1,25-(OH)2D plasma levels were reduced 28% in broilers with valgus-varus deformities but normal in broilers with TD. Anatomically, there were three different patterns of bone development in the undecalcified mid-diaphyseal sections. The pattern with the least periosteal growth, lowest tetracycline labeling, and smallest marrow cavity was most often seen in valgus-varus deformities. Patterns with greatest periosteal growth, high tetracycline labeling, and larger marrow cavities were more representative of normal broilers. It was hypothesized that defective prostaglandin metabolism reduced 1,25-(OH)2D levels, contributing to the overall reduction in bone formation and bone resorption observed in broilers with valgus-varus bone deformity.
对49日龄雄性肉鸡的维生素D代谢物水平和胫跗骨组织形态计量学特征进行了测定。在看似正常的营养、空间和光照条件下，在地面垫料上饲养的这些肉鸡中，5.2%存在内外翻骨畸形，3%存在胫骨软骨发育不良（TD）。正常肉鸡和跛行肉鸡之间未观察到显著的体重差异。跛行肉鸡和正常肉鸡的血浆25-OH-D水平相同。然而，内外翻畸形肉鸡的血浆1,25-(OH)2D水平降低了28%，而患有TD的肉鸡则正常。在解剖学上，未脱钙的骨干中段切片中有三种不同的骨发育模式。骨膜生长最少、四环素标记最低且骨髓腔最小的模式最常出现在内外翻畸形中。骨膜生长最大、四环素标记高且骨髓腔较大的模式更具正常肉鸡的代表性。据推测，前列腺素代谢缺陷降低了1,25-(OH)2D水平，导致在患有内外翻骨畸形的肉鸡中观察到的骨形成和骨吸收总体减少。
