Influence of incremental zeranol implant doses on the chemical and physical characteristics of third metacarpal bone and chemical composition of liver and soft tissue from feedlot steers.
Influence of incremental zeranol implant doses on the chemical and physical characteristics of third metacarpal bone and chemical composition of liver and soft tissue from feedlot steers.
复制标题
玉米赤霉醇植入剂量增量对第三掌骨化学和物理特性以及饲养场公牛肝脏和软组织化学成分的影响。
DOI：
10.2527/1995.7311
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发表时间：
1995
影响因子：
3.3
通讯作者：
D C Kenison
中科院分区：
文献类型：
--
作者：
N D Turner;L W Greene;F. Byers;D C Kenison
对肥育场阉牛第三掌骨、肝脏和肋骨软组织成分的理化特性进行了测定。选择阉牛（每个实验地点32头），以代表3个（总计n = 1，088）饲养场实验中每个处理组的屠宰体重和组成范围。在屠宰前约140天，向阉牛植入0、24、36、48、60、72、84或96 mg玉米赤霉醇。每个地点的牛喂养相同的天数，并作为一组屠宰。玉米赤霉醇剂量对骨骼、肝脏或肋骨软组织的化学成分没有影响，但以下情况除外：玉米赤霉醇降低（P <0.01）骨骼Ca浓度，增加（P <0.07）肝脏P浓度。Zeranol植入减少了髓腔前后径（AP）和AP皮质宽度（P <0.08）。骨承受的载荷直至弯曲（P <0.08）和弯曲时的应变（P <0.09）与玉米赤霉醇剂量的平方成反比。然而，弯曲和断裂时的弹性模量随着玉米赤霉醇剂量的增加而增加。对于植入的牛，弯曲处骨所承受的应力更大（P <0.09）。应变数据表明，与对照组相比，接受玉米赤霉醇的阉牛掌骨在加载至弯曲时表现出更小的变形（P <0.09）。这些数据表明，给予中等剂量的玉米赤霉醇改变了钙的骨沉积，从而导致第三掌骨的物理和机械特性发生改变。
Chemical and physical characteristics of third metacarpal bones and liver and rib soft tissue composition from feedlot steers were determined. Steers were selected (32 from each experimental location) to represent the range in slaughter weight and composition for each treatment group in three (total n = 1,088) feedlot experiments. Steers were implanted with 0, 24, 36, 48, 60, 72, 84, or 96 mg of zeranol at approximately 140 d before slaughter. Cattle at each location were fed for the same number of days and slaughtered as a group. Zeranol dose had no effect on the chemical composition of bone, liver, or rib soft tissue with the following exceptions: zeranol decreased (P < .01) bone Ca concentration and increased (P < .07) liver P concentration. Zeranol implantation decreased medullary cavity anterioposterior (AP) diameters and AP cortical width (P < .08). Loads withstood by the bones up to flexure (P < .08) and the strain at flexure (P < .09) were inversely related to the quadratic of zeranol dose. However, modulus of elasticity at flexure and breaking increased numerically with zeranol dose. Stress withstood by bones at flexure was greater (P < .09) for implanted steers. Strain data indicate that metacarpals from steers receiving zeranol would exhibit less deformation upon loading to flexure (P < .09) than controls. These data indicate that administration of intermediate doses of zeranol altered bone deposition of Ca, which resulted in modified third metacarpal physical and mechanical characteristics.