Department of Animal Science, Michigan State University, East Lansing, 48824 MI, United States.
Department of Animal Science, University of California, Davis, Davis, 95616 CA, United States.
Poult Sci. 2019 Feb 1;98(2):1017-1022. doi: 10.3382/ps/pey373.
Damage to the keel bone is a major issue in the laying hen industry. The goal of this study was to compare palpation results of live laying hens to digital computed tomography (CT) images, to assess changes in palpation reliability as training and familiarity increased, and to examine keel bone morphology over time. The longitudinal study consisted of 2 trials of 3 observation periods using 40 different (n = 120) W-36 hens housed in enriched colony cages. The first trial began when hens were 52 to 58 wk of age repeating the trial when the same birds were 74 to 81 wk of age. At 52 wk of age, each hen's keel bone was palpated by a single individual for keel bone caudal tip fractures (Tip), sagittal deviations (Evenness), and transverse deviations (Straightness). After palpation, each hen was placed in a motion limiting restraint and scanned using CT. The hens spent the next 21 d in their cages and on day 21, the hens were collected, palpated, and CT scanned again. The CT scans were imported into Mimics analysis software, 3D models of each keel bone were constructed and evaluated. Each bone and 3D model was scored (0, 1, 2) on the measurement of transverse deviation based on <0.5 cm, 0.51 to 1.0 cm, and >1.0 cm total deviation, respectively. Analysis of data using Proc Freq and Means in SAS 9.3 revealed minimal to moderate kappa values and moderate agreement percentages between palpators and digital analysis. The computer generated 3D models of individual keel bones were compared to palpation scores for Tip, Evenness, and Straightness at the beginning and end of each trial. The visual observations of the 3D models were qualitative, performed by a single individual. Overall, we found CT scanning to be a useful tool in observing changes to the keel bone, we observed changes in palpation accuracy as training/familiarity increased, and examined changes in keel morphology, specifically in the tip, after 52 wk of age.
龙骨损伤是蛋鸡养殖业的一个主要问题。本研究的目的是比较活鸡产蛋鸡的触诊结果与数字计算机断层扫描（CT）图像，评估随着训练和熟悉程度的提高，触诊可靠性的变化，并随着时间的推移检查龙骨骨形态的变化。这项纵向研究包括使用 40 只不同的（n = 120）W-36 母鸡进行的 2 次试验，3 个观察期，这些母鸡被安置在丰富的鸡笼中。第一次试验在母鸡 52 至 58 周龄时开始，当同一批母鸡 74 至 81 周龄时重复该试验。在 52 周龄时，每只母鸡的龙骨骨由一个人进行触诊，以确定龙骨骨末端骨折（尖端）、矢状偏差（均匀度）和横偏（直度）。触诊后，每只母鸡都被放入一个限制运动的固定器中，并进行 CT 扫描。母鸡在鸡笼中度过接下来的 21 天，在第 21 天，母鸡被收集起来，再次进行触诊和 CT 扫描。CT 扫描被导入 Mimics 分析软件，对每个龙骨骨的 3D 模型进行构建和评估。基于总偏差<0.5 厘米、0.51 至 1.0 厘米和>1.0 厘米，每个骨骼和 3D 模型分别进行（0、1、2）评分，以评估横向偏差的测量。使用 SAS 9.3 中的 Proc Freq 和 Means 分析数据，结果显示触诊者和数字分析之间的kappa 值最小到中度，一致性百分比为中度。个体龙骨骨的计算机生成的 3D 模型与每次试验开始和结束时的尖端、均匀度和直度的触诊评分进行了比较。3D 模型的视觉观察是定性的，由一个人进行。总的来说，我们发现 CT 扫描是观察龙骨骨变化的有用工具，我们观察到随着训练/熟悉程度的提高，触诊准确性发生了变化，并且在 52 周龄后检查了龙骨形态的变化，特别是在尖端。
