Behavioral, endocrine, immune, and performance measures for pigs exposed to acute stress.

Abstract

Weanling pigs (n = 132) were used to investigate the effects of three common stressors (and a control) and differing social status on behavior, immunity, plasma cortisol, blood chemical, and performance measures. Eleven blocks of 12 pigs each were evaluated. Each pen contained three pigs of dominant (DOM), intermediate (INT), or submissive (SUB) social status. Two weeks later, random pens of pigs experienced either a control treatment (CON) or they were stressed for 4 h by shipping (SHIP), heat-stressed (HEAT) with overhead heat lamps in their home pens, or cold-stressed (COLD) by direct application of water and an air current. Treatments did not influence body weights; however, percentage weight loss during SHIP was greater than for other treatments. Body weights were heavier for DOM pigs than for INT and SUB pigs. Social status had large effects on plasma cortisol, globulin, acute-phase proteins, body weight, and weight changes. Only acute shipping stress resulted in weight loss. Many immune and blood measures were not changed among acutely stressed pigs; however, the relationship between social status and mitogen-induced lymphocyte proliferation and natural killer cell cytotoxicity was disrupted during acute stress. Pig behavior was significantly changed by each stress treatment in a unique manner. During acute stress, behavioral changes seem to be the most consistent and reliable indicators.

Heat stress upregulation of Toll-like receptors 2/4 and acute inflammatory cytokines in peripheral blood mononuclear cell (PBMC) of Bama miniature pigs: an in vivo and in vitro study

“…Although many stressors have been reported to increase plasma cortisol concentrations in pigs (Becker et al, 1985;Parrott and Misson, 1989), conflicting results have been reported by other researchers. For example, lower cortisol levels were detected in heat-stressed pigs compared with coldstressed and transportation-stressed pigs, with statistically similar values for cortisol compared with control pigs (Hicks et al, 1998, Sutherland et al, 2006. Furthermore, heat stress did not increase plasma cortisol in cows with the exception of a slight elevation on the first day of heat stress (Farooq et al, 2010).…”

“…Stressors activate the hypothalamic-pituitary-adrenal axis, resulting in elevated corticotrophin-releasing hormone, which induces the release of ACTH and other peptides. Elevated ACTH stimulates the release of glucocorticoids from the adrenal cortex into the blood of stressed farm animals (Hicks et al, 1998). Although many stressors have been reported to increase plasma cortisol concentrations in pigs (Becker et al, 1985;Parrott and Misson, 1989), conflicting results have been reported by other researchers.…”

Group housing during gestation affects the behaviour of sows and the physiological indices of offspring at weaning

“…These changed biochemical indices in the offspring may indicate body condition differences, which may possibly lead to differences in growth in later life. In addition to physiological changes, animal behaviour also demonstrated responses to environment stressors (Hicks et al, 1998). Sows housed in groups demonstrated significantly higher drinking frequency than those in the stalls.…”

Physiology and behavior of pigs before and after castration: effects of two topical anesthetics

“…Tri-Solfen was also shown to be effective in reducing the post-procedural pain caused by surgical castration and tail docking (Paull et al, 2009;Lomax et al, 2010) and museling (Lomax et al, 2008) in lambs. Changes in leukocyte numbers and percentages can occur in response to acute stress in pigs (Hicks et al, 1998;Niekamp et al, 2007;Sutherland et al, 2009). This phenomenon is known as leukocyte trafficking and is thought to reflect the redistribution of leukocytes to lymph nodes, bone marrow and skin (Dhabhar, 2002).…”