School of Sciences, Engineering & Environment, Peel Building, University of Salford, Manchester M5 4WT, England.
Departamento de Evolução, Biodiversidade e Meio Ambiente, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, s/n, Bauxita, Cep: 35400-000 Ouro Preto, Minas Gerais, Brazil.
Behav Processes. 2022 Jun;199:104662. doi: 10.1016/j.beproc.2022.104662. Epub 2022 May 27.
Studies with humans and some other animal species have shown that sleep is compromised when the presence of external factors such as light, sound, and temperature surpass normal levels. This study investigated the effects of these environmental conditions on 13 kennelled laboratory dogs, assessing whether each variable interfered with their sleep behaviour and/or increased stress responses, which could further compromise sleep quality. The behaviour of dogs was video recorded for eight months. Diurnal and nocturnal behaviour were recorded, along with naturally occurring levels of temperature, light and sound in the dogs' kennel environment. Faecal cortisol metabolites (FCM), from samples collected every morning, were used to monitor the dogs' adrenocortical activity. GLMM models and non-parametric tests were conducted to evaluate the relationship between sleeping patterns, environmental variables, and stress on the studied dogs. Nocturnal sleep decreased in response to increases in temperature and in day light duration. No effects of sound and FCM levels on dogs' sleep were observed. However, diurnal sleep was affected by sound and FCM levels, decreasing when both factors increased. Additionally, noisier days increased stress responses, especially in male dogs. Increased FCM levels were associated with changes in the diurnal behaviour of dogs; for example, decreased activity. The decrease in daily activities and increased physiological stress responses could be associated with maladaptation to the environment, which could indicate poor welfare. Our study suggests that mitigating the impact of environmental conditions in the kennels could improve sleep quality and the overall quality of life of the dogs.
已有研究表明，当光照、声音和温度等外部因素超过正常水平时，人类和其他一些动物的睡眠质量就会受到影响。本研究调查了这些环境条件对 13 只关在犬舍里的实验室犬的影响，评估了每个变量是否会干扰它们的睡眠行为和/或增加应激反应，从而进一步影响睡眠质量。研究人员对犬只的行为进行了长达 8 个月的视频记录，记录了犬只的昼夜行为以及犬舍环境中自然发生的温度、光照和声音水平。每天早上收集粪便皮质醇代谢物（FCM）样本，以监测犬只的肾上腺皮质活动。使用广义线性混合模型（GLMM）和非参数检验来评估睡眠模式、环境变量和应激与研究犬之间的关系。结果表明，温度和光照时间的增加导致犬只夜间睡眠时间减少。没有观察到声音和 FCM 水平对犬只睡眠的影响。然而，声音和 FCM 水平会影响犬只的日间睡眠，当这两个因素增加时，犬只的日间睡眠时间会减少。此外，噪音较大的日子会增加应激反应，尤其是雄性犬只。FCM 水平的升高与犬只日间行为的变化有关，例如活动减少。犬只日常活动减少和生理应激反应增加可能与对环境的不适应有关，这可能表明其福利状况较差。本研究表明，减轻犬舍环境的影响可能会提高犬只的睡眠质量和整体生活质量。
