Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, Onderstepoort, South Africa.
Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, Onderstepoort, South Africa.
PLoS One. 2020 Jun 25;15(6):e0234971. doi: 10.1371/journal.pone.0234971. eCollection 2020.
Intensive pig management involves in a commercial setting the housing and implementation of certain procedures, such as castration and tail docking, which may be stressful for the animal. Good farming practices include the reduction of stress due to management processes, but assessing the level of stress perceived entirely through behavioural observations can be challenging. The monitoring stress-related physiological markers, like glucocorticoids (GC), can be an accurate alternative that would presumably be more objective. In order to avoid an additional stressor by taking blood, a non-invasive approach is advisable. We used an adrenocorticotropic hormone (ACTH) stimulation test and the effect of transport to examine the suitability of different enzyme immunoassays (EIAs) for monitoring adrenocortical function in domestic pigs using saliva and faeces as sample matrices. An assay measuring faecal glucocorticoid metabolites (fGCMs) with a 3ß,11ß-diol group has proven suited to determine adrenocortical activity, showing an overall increase of 180% in fGCM concentrations related to ACTH administration and of 70% related to transport, respectively. A cortisol EIA was used to detect salivary glucocorticoid (sGC) concentrations, revealing a 1100% increase in sGC concentrations after ACTH administration. The stability of fGCM concentrations post-defecation was determined to assess possible changes in measured fGCM concentrations in unpreserved faecal material over time, with fGCM concentrations being relatively stable (maximal 12% change) under natural conditions for approximately two days after defecation. This implicates that untreated faecal material from pigs can be analysed for up to two days after collection without appreciable level of depreciation in fGCM concentrations. Being able to assess the physiological stress response of domestic pigs non-invasively can help to improve the well-being of commercially reared pigs.
集约化养猪涉及在商业环境中进行住房和实施某些程序，例如去势和断尾，这可能对动物造成压力。良好的养殖实践包括减少因管理过程引起的压力，但完全通过行为观察来评估感知到的压力水平可能具有挑战性。监测与压力相关的生理标志物，如糖皮质激素（GC），可以作为一种准确的替代方法，这可能更为客观。为了避免因采血而增加额外的应激源，建议采用非侵入性方法。我们使用促肾上腺皮质激素（ACTH）刺激试验和运输的影响来研究不同酶联免疫吸附测定（EIA）在使用唾液和粪便作为样本基质监测家猪肾上腺皮质功能方面的适用性。一种测量粪便糖皮质激素代谢物（fGCM）的方法，其中 3β，11β-二醇基团已被证明适合于确定肾上腺皮质活性，与 ACTH 给药相关的 fGCM 浓度总体增加 180％，与运输相关的 fGCM 浓度分别增加 70％。使用皮质醇 EIA 检测唾液中的糖皮质激素（sGC）浓度，发现 ACTH 给药后 sGC 浓度增加了 1100％。通过确定粪便排泄后 fGCM 浓度的稳定性来评估未经保存的粪便材料中测量的 fGCM 浓度随时间可能发生的变化，在自然条件下，粪便排泄后大约两天内，fGCM 浓度相对稳定（最大变化 12％）。这意味着可以在收集后长达两天的时间内分析未经处理的猪粪便材料，而不会导致 fGCM 浓度明显下降。能够非侵入性地评估家猪的生理应激反应有助于提高商业养殖猪的福利。
