Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Poult Sci. 2012 Nov;91(11):2736-46. doi: 10.3382/ps.2012-02322.
Femoral fractures are observed in selective-bred commercial turkeys; however, the etiology of such fractures is unknown. The current study investigated the whole bone morphological, material-level mechanical, and bone ash properties to determine the effect of selective breeding on bone strength. Femora from 3 divergent strains of turkeys, a commercial line, a different selectively bred heavy line (F-line), and a lighter age or weight matched random-bred line (RBC2/R-EQ, respectively), were compared. Bone geometric properties were measured with micro-CT and bone mechanical properties were measured using 3-point bending tests. Whole bone ash quantities were also recorded. Statistics were run using a general linear model multivariate ANOVA (GLM ANOVA). Results showed that at similar ages, the faster growing birds (commercial and F-line) had femurs twice the size of the RBC2 line as measured by cross-sectional area as early as 8 wk into the study. The femurs of the commercial and F-lines also exhibited as much as 20% greater mechanical strength than femurs from the RBC2 line at 16 and 20 wk of age as measured by properties such as elastic modulus and ultimate tensile strength. However, at similar BW, the slower growing R-EQ line had higher mechanical properties than the other lines, with the elastic modulus being 40% greater and the ultimate tensile strength being 37% greater at weights equivalent to those of the commercial and F-lines at 12 wk of age. Moreover, it was observed that the morphological properties (i.e., cross-sectional area, moments of inertia) are largely governed by BW, as there is little difference in the amount gained per week of age across the different lines. Conversely, the mechanical properties, as well as the related ash content, appear to be governed at least in part by time. Therefore, whereas modulation of bone geometry is the key responder for changes in BW, sufficient time for matrix mineralization or maturation or both to occur is also essential for mechanical competence of bone.
选育商业火鸡中可见股骨骨折；然而，这种骨折的病因尚不清楚。本研究调查了整个骨骼形态、材料水平力学和骨灰特性，以确定选择育种对骨骼强度的影响。比较了来自 3 个不同火鸡品系的股骨，包括商业系、不同的选择性选育重型系（F 系）和较轻的年龄或体重匹配的随机选育系（RBC2/R-EQ）。使用微 CT 测量骨几何特性，使用三点弯曲试验测量骨力学特性。还记录了全骨灰分的数量。使用一般线性模型多变量方差分析（GLM ANOVA）进行统计分析。结果表明，在相似的年龄下，生长较快的鸟类（商业和 F 系）的股骨截面积是 RBC2 系的两倍，早在研究进行到 8 周时就可以观察到这一点。在 16 和 20 周龄时，商业和 F 系的股骨的机械强度比 RBC2 系的股骨高 20%，这是通过弹性模量和极限拉伸强度等特性来衡量的。然而，在相似的 BW 下，生长较慢的 R-EQ 系的机械性能比其他系更高，弹性模量高 40%，极限拉伸强度高 37%，相当于 12 周龄商业和 F 系的体重。此外，观察到形态特性（即，横截面积，惯性矩）主要由 BW 决定，因为不同系之间每周增加的量差异很小。相反，力学性能以及相关的灰分含量，似乎至少部分受到时间的控制。因此，虽然骨几何形状的调节是 BW 变化的关键响应者，但基质矿化或成熟或两者都发生的足够时间对于骨骼的机械性能也是必不可少的。
