Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2004
Publication Date: 7/25/2004
Citation: Lay, Jr., D.C., Kattesh, H.G., Roberts, M.P., Toscano, M.J., McMunn, K.A. 2004. Effects of mixing stress on plasma cortisol, corticosteroid-binding globulin and free cortisol index in prenatally-stressed pigs [abstract]. Journal of Animal Science. 82:279.
Technical Abstract: Exposing a pregnant sow to stress has been shown to have negative effects on her resulting offspring. However, little knowledge exists regarding the mechanisms of this process or the effects of specific stressful events. Our objective was to determine if exposing a sow to stress altered the response of her offspring to mixing stress at 4 mo of age. Sow treatments consisted of i.v. injections of adrenocorticotrophin (ACTH, 1 IU/kg BW) (ACTH), exposure to rough handling for a 10-minute duration (ROU), or no treatment (CONT) once a week during d 42 to 77 of gestation. At 4 mo of age, one pig from each litter (n = 14, 14, 15) was taken from its home pen and placed in a pen of unfamiliar pigs. Blood samples were collected three times per week for two weeks and then once a week for four more weeks. Blood samples were analyzed for cortisol and corticosteroid-binding globulin (CBG), and a free cortisol index (FCI; total cortisol/CBG) was calculated. In response to treatments, ACTH sows had greater concentrations of cortisol than did ROU sows, which had greater concentrations than CONT sows (77.1, 46.0 and 32.1 ng/mL, P < .004). CBG concentrations in pigs from CONT sows tended to be lower (P < .06) than pigs from ROU sows and was lower (P < .008) than pigs from ACTH sows (4.75 ± .10, 5.2 ± .12, and 5.51 ± .13 mg/L, respectively). An effect of gender was also detected with females having greater (P < .001) concentrations of CBG than males. No treatment differences (P < .10) were found for either plasma cortisol concentrations or FCI. A treatment by repetition (P < .02) and repetition effect (P < .04) were noted for both plasma cortisol and FCI. Prenatal stress, induced either artificially with injections of ACTH, or via rough handling, changes CBG responses compared to controls but does not alter either FCI or plasma cortisol concentrations. The degree to which effects of prenatal stress are induced in production livestock needs to be sought.