Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
IRTA, Animal Welfare Subprogram, Veïnat de Sies, s/n, Monells, Spain.
PLoS One. 2019 Jan 16;14(1):e0210406. doi: 10.1371/journal.pone.0210406. eCollection 2019.
How housing and transport conditions may affect welfare in porcine production is a leading topic in livestock research. This study investigated whether pigs present a different neurological response to management conditions and to ascertain whether pigs living partially outdoors cope differently with road transport-associated stress. Twenty-four female pigs were divided in two groups: one living indoors (ID, n = 12) and the other housed combining indoor conditions with 4 hours per day of outdoor pasture (OD, n = 12). After one month, one set of animals from each housing condition were driven in a truck to the slaughterhouse in low-stress conditions (5 min drive, no mixing groups, soft management, LS group, n = 12) or high-stress conditions (2 hours drive, mixing groups, harsh management, HS group, n = 12). At the slaughterhouse, blood was collected, and the prefrontal cortex (PFC) and the hippocampus (HC) dissected. OD pigs had lower serum haptoglobin and increased dopaminergic pathway (DA-system) in the PFC, suggesting that living outdoors increases their wellbeing. HS conditions increased serum creatine kinase (CK) and affected several brain pathways: activation of the noradrenergic (NA-system) and DA -system in the PFC and the activation of the DA-system and an increase in c-Fos as well as a decrease in brain-derived neurotrophic factor (BDNF) in the HC. The serotonergic system (5-HT-system) was mildly altered in both areas. There was an interaction between housing and transport in serum NA and the DA-system in the HC, indicating that living conditions affected the response to stress. Multivariate analysis was able to discriminate the four animal groups. In conclusion, this work indicates that housing conditions and road transport markedly modifies the neurophysiology of pigs, and suggests that animals raised partially outdoors respond differently to transport-associated stress than animals raised indoors, indicating that they cope differently with unknown environments.
住房和交通条件如何影响养猪福利是畜牧业研究的一个主要课题。本研究调查了猪对管理条件是否有不同的神经反应，并确定了部分户外饲养的猪在应对与道路运输相关的应激时是否有不同的反应。24 头母猪被分为两组：一组室内饲养（ID，n=12），另一组室内饲养并每天户外放牧 4 小时（OD，n=12）。一个月后，每组中的一组动物在低应激条件下（5 分钟车程，不混合组，软性管理，LS 组，n=12）或高应激条件下（2 小时车程，混合组，严格管理，HS 组，n=12）被卡车运往屠宰场。在屠宰场，采集血液，并解剖前额叶皮质（PFC）和海马（HC）。OD 猪的血清结合珠蛋白较低，PFC 中的多巴胺能途径（DA 系统）增加，表明户外生活增加了它们的幸福感。HS 条件增加了血清肌酸激酶（CK），并影响了几个大脑途径：PFC 中的去甲肾上腺素能（NA 系统）和 DA 系统的激活，以及 HC 中的 DA 系统的激活、c-Fos 的增加以及脑源性神经营养因子（BDNF）的减少。5-羟色胺系统（5-HT 系统）在两个区域都有轻度改变。在血清 NA 和 HC 中的 DA 系统中，住房和运输之间存在相互作用，表明生活条件影响了对压力的反应。多变量分析能够区分四个动物群体。总之，这项工作表明，住房条件和道路运输显著改变了猪的神经生理学，并表明部分户外饲养的动物对与运输相关的应激的反应不同于室内饲养的动物，这表明它们对未知环境的应对方式不同。
