title: Causes, consequences and biomarkers of stress in swine: an update.
abstract: BACKGROUND
  In recent decades there has been a growing concern about animal stress on intensive pig farms due to the undesirable consequences that stress produces in the normal physiology of pigs and its effects on their welfare and general productive performance. This review analyses the most important types of stress (social, environmental, metabolic, immunological and due to human handling), and their biological consequences for pigs. The physio-pathological changes associated with stress are described, as well as the negative effects of stress on pig production. In addition an update of the different biomarkers used for the evaluation of stress is provided. These biomarkers can be classified into four groups according to the physiological system or axis evaluated: sympathetic nervous system, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-gonadal axis and immune system.
  
  
  CONCLUSIONS
  Stress it is a process with multifactorial causes and produces an organic response that generates negative effects on animal health and production. Ideally, a panel of various biomarkers should be used to assess and evaluate the stress resulting from diverse causes and the different physiological systems involved in the stress response. We hope that this review will increase the understanding of the stress process, contribute to a better control and reduction of potential stressful stimuli in pigs and, finally, encourage future studies and developments to better monitor, detect and manage stress on pig farms.
authors.affiliation: Department of Animal Production, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain. silviamm@um.es.
authors.forename: Silvia
authors.initials: S
authors.lastname: Martínez-Miró
authors.affiliation: Department of Animal Medicine and Surgery, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain. ftecles@um.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Tecles
authors.affiliation: Department of Animal Production, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Ramón
authors.affiliation: Department of Animal Medicine and Surgery, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: Damián
authors.initials: D
authors.lastname: Escribano
authors.affiliation: Department of Animal Production, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: Fuensanta
authors.initials: F
authors.lastname: Hernández
authors.affiliation: Department of Animal Production, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: Josefa
authors.initials: J
authors.lastname: Madrid
authors.affiliation: Department of Animal Production, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Orengo
authors.affiliation: Department of Animal Medicine and Surgery, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Martínez-Subiela
authors.affiliation: Department of Animal and Food Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Manteca
authors.affiliation: Department of Animal Medicine and Surgery, Campus of Excellence Mare Nostrum, Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: José Joaquín
authors.initials: JJ
authors.lastname: Cerón
mesh_terms: D000822:Animal Husbandry / Q000639:trends; D000818:Animals; D015415:Biomarkers; D013312:Stress, Physiological; D013552:Swine
chemical_list: D015415:Biomarkers
keywords: Biomarkers; Pigs; Stress