Makagon Maja M, Pullin Allison N, Rufener Christina B, Tarlton John, Toscano Michael, Blatchford Richard A
Department of Animal Science, Center for Animal Welfare, University of California, Davis, CA 95616.
Department of Animal Science, Center for Animal Welfare, University of California, Davis, CA 95616.
Poult Sci. 2024 Dec;103(12):104245. doi: 10.1016/j.psj.2024.104245. Epub 2024 Aug 22.
The skeletal health of laying hens improves when birds are given opportunities to perform load-bearing movements with elevated structures, such as perches. We investigated how early access to elevated structures varying in complexity and height would affect bone quality and subsequent keel bone fractures in a layer multitiered aviary. Female Dekalb White pullets were reared in floor pens furnished with floor perches (FL), single-tiered aviaries (ST), or 2-tiered aviaries (TT; n = 5 pens/treatment) through 16 wk of age. At 17 wks, all structures were replaced with identical multitiered layer aviaries. The keel, both tibiae, and both humeri were collected from 60 euthanized birds from each rearing treatment at 8, 16 and 30 wk of age, and analyzed with dual X-ray absorptiometry (DEXA) for bone mineral density and length. At 18, 26, 28, and 30 wk of age, 10 focal hens/pen were radiographed repeatedly and the presence, severity of keel bone fractures were assessed with a tagged visual analogue scale. The number of fractures was also recorded. At 16 wk of age, FL pullets had lower BMD of the tibia (P = 0.003), keel (P = 0.013), and humerus (P = 0.004) compared to ST and TT pullets. Most of the observed treatment differences disappeared after pullets were transferred to the aviary. BMD continued to increase for all hens through 30 wk of age. Pullet rearing did not affect the presence or severity of keel bone fractures, or number of new fractures incurred between ages (P > 0.05). The prevalence and severity of keel bone fractures increased between 26 to 28 wk and remained high to 30 wk of age (P < 0.0001). Hens experienced more new fractures between 26 to 30 wk than between 18 to 26 wk of age (P = 0.0046). The effects of pullet housing on bone quality were short-term when hens had access to adult housing with multiple opportunities for load-bearing movements. Keel fractures with minor severity were high in prevalence reflecting the use of radiography to assess this injury.
当蛋鸡有机会利用诸如栖木等高架结构进行承重运动时，其骨骼健康状况会得到改善。我们研究了早期接触不同复杂度和高度的高架结构如何影响蛋鸡多层禽舍中骨骼质量及随后的龙骨骨折情况。将迪卡白母鸡饲养在配备地面栖木（FL）、单层禽舍（ST）或双层禽舍（TT；每组n = 5个禽舍）中的地面围栏中，直至16周龄。17周龄时，所有结构都更换为相同的多层蛋鸡禽舍。在8、16和30周龄时，从每种饲养方式下安乐死的60只鸡中采集龙骨、双侧胫骨和双侧肱骨，并用双能X线吸收法（DEXA）分析骨矿物质密度和长度。在18、26、28和30周龄时，对每个禽舍中的10只重点鸡进行反复X光摄影，并用带标签的视觉模拟量表评估龙骨骨折的存在情况和严重程度。还记录骨折数量。在16周龄时，与ST和TT母鸡相比，FL母鸡的胫骨（P = 0.003）、龙骨（P = 0.013）和肱骨（P = 0.004）的骨密度较低。在母鸡转移到禽舍后，观察到的大多数处理差异消失。所有母鸡的骨密度在30周龄前持续增加。母鸡饲养方式对龙骨骨折的存在情况、严重程度或不同年龄段之间新发生骨折的数量没有影响（P > 0.05）。龙骨骨折的患病率和严重程度在26至28周龄之间增加，并在30周龄时保持在较高水平（P < 0.0001）。母鸡在26至30周龄之间比在18至26周龄之间经历更多新骨折（P = 0.0046）。当母鸡能够进入有多次承重运动机会的成年禽舍时，雏鸡饲养方式对骨骼质量的影响是短期的。轻度龙骨骨折的患病率较高，这反映了使用X光摄影来评估这种损伤。
