Sibanda Terence Zimazile, O'Shea Cormac J, de Souza Vilela Jessica, Kolakshyapati Manisha, Welch Mitchell, Schneider Derek, Courtice Jodi, Ruhnke Isabelle
School of Environmental and Rural Science, Faculty of Science, Agriculture, Business and Law, University of New England, Armidale, NSW 2351, Australia.
School of Biosciences, University of Nottingham, Nottingham LE12 5RD, UK.
Animals (Basel). 2020 Oct 18;10(10):1911. doi: 10.3390/ani10101911.
While free-range laying hens frequently experience health and welfare challenges, the contribution of range use towards these risks are largely unknown. The aim of this pilot study was to investigate the survival, health and welfare of commercial free-range laying hens and explore the association with early range use. Range use of 9375 Lohmann Brown hens housed within five flocks was assessed during 18-21 weeks of age and individual hens were classified as "rangers" (frequent range users), "roamers" (intermittent range users), and "stayers" (rare/no range users) were then subject to necropsy at 74 weeks of age. Rangers and roamers were three times and 2.4 times more likely to survive than stayers, respectively ( = 0.001). Overall, rangers had significantly better feather cover and more lesions associated with spotty liver diseases compared to roamers and stayers ( = 0.001). Similarly, rangers and roamers had a higher prevalence of infection and less frequent signs of fatty liver syndrome compared to stayers. Rangers had a higher proportion of hens with full ovary follicle production compared to stayers and roamers ( = 0.035). This information is highly relevant to consider the targeted support of different flock subpopulations to improve hen health and welfare, directly affecting farm profitability. Further research on other farms is warranted to investigate the transferability of the observed results.
虽然自由放养的蛋鸡经常面临健康和福利挑战，但活动场地的使用对这些风险的影响在很大程度上尚不清楚。这项初步研究的目的是调查商业自由放养鸡的存活情况、健康状况和福利，并探讨与早期使用活动场地之间的关联。在18至21周龄期间，对五个鸡群中饲养的9375只罗曼褐蛋鸡的活动场地使用情况进行了评估，个体母鸡被分为“常去者”（频繁使用活动场地者）、“偶尔去者”（间歇性使用活动场地者）和“常留者”（很少/不使用活动场地者），然后在74周龄时进行剖检。“常去者”和“偶尔去者”存活的可能性分别是“常留者”的3倍和2.4倍（P = 0.001）。总体而言，与“偶尔去者”和“常留者”相比，“常去者”的羽毛覆盖情况明显更好，与斑点状肝病相关的病变更多（P = 0.001）。同样，与“常留者”相比，“常去者”和“偶尔去者”感染的患病率更高，脂肪肝综合征的症状出现频率更低。与“常留者”和“偶尔去者”相比，“常去者”中卵巢卵泡完全发育的母鸡比例更高（P = 0.035）。这些信息对于考虑有针对性地支持不同鸡群亚群以改善母鸡健康和福利非常重要，这将直接影响农场的盈利能力。有必要在其他农场进行进一步研究，以调查观察结果的可转移性。
