IFM Biology, Linköping University, 58183 Linköping, Sweden.
IFM Biology, Linköping University, 58183 Linköping, Sweden.
Poult Sci. 2021 Jan;100(1):1-8. doi: 10.1016/j.psj.2020.10.015. Epub 2020 Oct 10.
In commercial egg production, laying hen chicks are exposed to several stressful events during incubation, hatching, and their first hours in life. We have previously shown that hatching and processing are associated with increased corticosterone concentration and further affect behavior and stress sensitivity in a short- as well as long-term perspective. However, it is not known whether these long-term stress effects are caused by the hatchery processing (sex sorting, vaccination, conveying, and loading for transport) or if they are mainly caused by potentially stressful events before processing, during incubation and hatching. In the present study, the aim was to assess the effects of incubation and hatching only, compared to stress effects from the entire hatchery processing. We compared Lohmann LSL chicks incubated, hatched, and processed in a commercial hatchery with chicks incubated and hatched at the same time but not further processed. We studied behavior in a novel arena and during tonic immobility, as well as weight development and corticosterone reaction during a stress challenge. Processed chicks had poorer weight development and were more active in the novel arena test. However, there were no significant differences between the groups in corticosterone reactivity or tonic immobility. When comparing with previous data, both groups had elevated corticosterone concentrations compared to what we had previously reported from chicks hatched under calm and non-stressful conditions. In conclusion, incubation and hatching alone caused long-term stress effects in chickens, but further processing exacerbated these effects to some extent.
在商业鸡蛋生产中，种鸡雏鸡在孵化、出雏和出生后的头几个小时内会经历多种应激事件。我们之前的研究表明，出雏和处理过程会导致皮质酮浓度升高，并在短期和长期内影响行为和应激敏感性。然而，目前尚不清楚这些长期应激效应是由孵化场处理（性别分拣、疫苗接种、运输中的输送和装载）引起的，还是主要由孵化和出雏前的潜在应激事件引起的。在本研究中，我们的目的是评估仅孵化和出雏的影响，与整个孵化场处理的应激效应进行比较。我们比较了在商业孵化场孵化、出雏和处理的 Lohmann LSL 雏鸡与同时孵化但未进一步处理的雏鸡。我们在一个新的竞技场和紧张性不动期间研究了行为，以及在应激挑战期间的体重发育和皮质酮反应。经过处理的雏鸡体重发育较差，在新的竞技场测试中更活跃。然而，两组在皮质酮反应性或紧张性不动方面没有显著差异。与之前的数据相比，两组的皮质酮浓度都高于我们之前在平静和非应激条件下孵化的雏鸡报告的数据。总之，单独的孵化和出雏会导致鸡产生长期应激效应，但进一步的处理在某种程度上加剧了这些效应。
