U.S. National Poultry Research Center, Egg Safety and Quality Research Unit, USDA Agricultural Research Service, Athens, Georgia 30605.
Department of Animal Science, Michigan State University, East Lansing, Michigan 48824.
Poult Sci. 2018 Jul 1;97(7):2347-2355. doi: 10.3382/ps/pex052.
In the United States, there is an increase in need for cage-free eggs in retail and food manufacturing sectors. Understanding the impact of cage-free systems and the corresponding management on egg quality is pertinent as the U.S. industry adapts existing housing and builds new cage-free housing structures. A study was conducted comparing 2 brown shell and 2 white shell hen strains housed in a cage-free aviary system. Each set of eggs were placed in cold storage and assessed at 0, 2, 4, 8, and 12 wk. Eggs were collected at 21, 31, 42, and 60 wk of hen age. A full profile of physical quality measurements was conducted on up to 18 intact eggs for each hen strain/egg storage/hen age combination. Egg weight increased approximately 10 g for brown shell and 14 g for white shell eggs as hens aged. Many of the properties monitored were significantly impacted by all 3 main effects (hen strain, egg storage, and hen age) resulting in 3-way interactions. A brown and a white shell strain had stronger shells (44 N; P < 0.0001) than the remaining brown and white shell strains (42 N and 39 N, respectively). The current study also determined volume of shell, total length, maximum width, and percent length at maximum width to more accurately indicate egg shape than shape index. One brown shell strain produced eggs with the most consistent shape characteristics over the hen ages monitored. White shell eggs from the cage-free aviary housing produced the highest whole-egg total solids between 31 to 60 wk of hen age, whereas brown shell eggs resulted in the most consistent level of whole-egg total solids (22-23.5%). The brown and white shell strains in the current study produce cage-free aviary eggs with distinctive physical quality attributes. The outcomes from this study can be utilized by the U.S. egg industry in planning management strategies and market placement of cage-free eggs.
在美国，零售和食品制造行业对无笼鸡蛋的需求不断增加。随着美国行业调整现有鸡舍并建造新的无笼鸡舍，了解无笼系统和相应管理对鸡蛋质量的影响至关重要。本研究比较了 2 个褐壳和 2 个白壳母鸡品种在无笼式禽舍系统中的饲养情况。每组鸡蛋均放置在冷藏库中，并在 0、2、4、8 和 12 周时进行评估。鸡蛋在母鸡年龄为 21、31、42 和 60 周时收集。对每个母鸡品种/鸡蛋冷藏/母鸡年龄组合的最多 18 个完整鸡蛋进行了全面的物理质量测量。褐壳鸡蛋和白壳鸡蛋的重量随着母鸡年龄的增长分别增加了约 10 克和 14 克。监测到的许多特性都受到母鸡品种、鸡蛋冷藏和母鸡年龄这 3 个主要因素的显著影响，从而产生了 3 因素交互作用。一个褐壳和一个白壳品种的蛋壳比其余的褐壳和白壳品种（分别为 42 N 和 39 N）更坚固（44 N；P < 0.0001）。本研究还确定了蛋壳体积、总长度、最大宽度和最大宽度处的长度百分比，以比形状指数更准确地指示鸡蛋形状。一个褐壳品种在监测的母鸡年龄范围内生产的鸡蛋形状特征最一致。无笼禽舍饲养的白壳鸡蛋在母鸡年龄为 31 至 60 周之间产生的全蛋总固体含量最高，而褐壳鸡蛋则产生最一致的全蛋总固体含量（22-23.5%）。本研究中的褐壳和白壳品种生产的无笼禽舍鸡蛋具有独特的物理质量特性。美国蛋鸡行业可以利用本研究的结果来规划无笼鸡蛋的管理策略和市场定位。
