|Berg, Erika - UNIVERSITY OF MISSOURI|
Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2003
Publication Date: March 15, 2004
Citation: Berg, E.L., Carroll, J.A. 2004. Growth performance, hormone profiles, and behavioral responses following castration are independent of piglet age [abstract]. Midwestern Section of the American Society of Animal Science Conference. 82(2):35. Technical Abstract: The objectives were to determine the effects of castration in pigs at 3, 6, 9, or 12 d of age on acute growth performance, hormone profiles, and behavior. Ninety-four intact male pigs were randomly assigned a treatment age by litter (3, 6, 9, or 12 d of age; n = 9-13 pigs/treatment/age group). Pigs within a litter were then assigned to castrated (C) or non-castrated (NC) treatment groups according to body weight. Pigs were non-surgically fitted with jugular catheters and blood samples drawn immediately prior to castration at time 0, and at 0.5, 1, 1.5, 2, 24 and 48 h post-castration. Body weights were obtained when the pigs were catheterized and at 24 and 48 h post-castration. Serum samples were analyzed for cortisol and dehydroepiandrosterone sulfate (DHEA-S). No differences (P=0.88) existed in initial body weight of pigs, and there was no overall treatment effect on growth performance of pigs at 24 h (P=0.98) or 48 h (P=0.94) post-treatment. There was a time-by-treatment effect (P<0.01) on serum cortisol concentrations, such that cortisol was greater in C pigs compared to NC pigs. There was no overall age effect of castration on serum cortisol (P=0.59). At 24 h post-castration, serum cortisol returned to baseline in all treatment groups (P=0.24). However, at 48 h post-castration, overall serum cortisol was elevated (P<0.01) in all pigs as compared to baseline concentrations. There was a time-by-treatment-by-age interaction (P<0.01) for serum DHEA-S such that serum DHEA-S decreased in C animals and increased in NC animals, and DHEA-S concentrations increased with age. During the first 2 h post-castration, C pigs spent more time (P=0.05) sitting than NC pigs, and there was a trend (P=0.09) for C pigs to be less active than NC pigs. However, no differences (P>0.05) were observed in the time pigs spent nursing or standing. These data indicate that castration is stressful regardless of age and that stress associated with handling appears to increase as the pig ages.