Fleming R H, Korver D, McCormack H A, Whitehead C C
Roslin Institute (Edinburgh), Roslin, Midlothian EH25 9PS, Scotland.
Poult Sci. 2004 Feb;83(2):207-14. doi: 10.1093/ps/83.2.207.
The genetic component of osteoporosis in caged laying hens is large, and a method for detecting hens susceptible to fracture could be useful in breeding programs. A radiographic absorptiometry film method was modified by video digitization from an image intensifier and computer analysis and termed digitized fluoroscopy (DF). Humeral and ulnar DF values were measured in 165 hens during lay. Relationships (P < 0.001) were seen between DF assessments from 25 wk onward and postmortem measurements at 70 wk. We conclude that DF can detect poor bones in hens early but is problematic. Quantitative ultrasound was also investigated. We measured amplitude-dependent speed-of-sound (Ad-SoS) in the third toe in hens. Nutritional studies revealed Ad-SoS values correlated with postmortem peripheral quantitative computerized tomography, (control group, r = 0.48, P < 0.001; treatment group, r = 0.39, P < 0.001). In caged and free-range hens, Ad-SoS correlated with shear strength (r = 0.33, P < 0.001, all hens) and radiographic density values (r = 0.53, P < 0.001, all hens) measured postmortem. The Ad-SoS values were higher in free-range than in caged hens (1,904 vs. 1,850 m/s, P < 0.001). Ad-SoS measurements were made in hens from a study where divergent genetic selection has produced high and low bone index lines with 92% difference in tibia strength. The value in high bone index hens was higher than in low bone index hens at 32 (P < 0.001), 42 (P < 0.001), 52 (P < 0.05), and 62 wk (P < 0.001) in generation 8. In an Ad-SoS heritability study, heritability estimates ranged from 0.15 to 0.39. We conclude that Ad-SoS is a heritable trait, reflects other bone measurements, and rapidly detects poor bone quality in hens.
笼养蛋鸡骨质疏松的遗传因素影响很大，因此，一种检测易骨折母鸡的方法对育种计划可能会很有用。通过对影像增强器的图像进行视频数字化处理及计算机分析，对射线吸收测定胶片法进行了改进，并将其称为数字化荧光透视法（DF）。在165只产蛋母鸡产蛋期间测量了其肱骨和尺骨的DF值。从25周龄起的DF评估值与70周龄时的死后测量值之间存在相关性（P < 0.001）。我们得出结论，DF能够早期检测出母鸡的骨骼状况不佳，但存在问题。同时也对定量超声进行了研究。我们测量了母鸡第三趾的振幅依赖声速（Ad-SoS）。营养研究表明，Ad-SoS值与死后外周定量计算机断层扫描相关（对照组，r = 0.48，P < 0.001；治疗组，r = 0.39，P < 0.001）。在笼养和放养母鸡中，Ad-SoS与死后测量的抗剪强度（r = 0.33，P < 0.001，所有母鸡）和射线密度值（r = 0.53，P < 0.001，所有母鸡）相关。放养母鸡的Ad-SoS值高于笼养母鸡（1,904对1,850米/秒，P < 0.001）。在一项研究中，对经过不同遗传选择产生了胫骨强度相差92%的高骨指数品系和低骨指数品系的母鸡进行了Ad-SoS测量。在第8代中，高骨指数母鸡在32周龄（P < 0.001）、42周龄（P < 0.001）、52周龄（P < 0.05）和62周龄（P < 0.001）时的Ad-SoS值高于低骨指数母鸡。在一项Ad-SoS遗传力研究中，遗传力估计值在0.15至0.39之间。我们得出结论，Ad-SoS是一种可遗传的性状，能反映其他骨骼测量结果，并能快速检测出母鸡骨骼质量不佳的情况。
