Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/6/1998
Publication Date: N/A
Technical Abstract: The goal of this experiment was to compare biological and behavioral indices of stress between boars experiencing frustration and pleasure. Mature boars (n=11) were trained to mount an artificial sow for semen collection purposes. Each boar was fitted with a jugular venous catheter to facilitate frequent blood sampling. Two treatments were imposed upon each animal: 1) a control (CTRL) condition of presumed pleasure wherein th boar proceeds with normal copulatory behavior culminating in ejaculation; and 2) a frustration (FRUS) treatment which allowed the boar to mount and display courtship behaviors toward the artificial sow but ejaculation was not allowed. Blood was sampled at frequent intervals for 30 min before, during, and for 30 min after exposure to the artificial sow. These samples were analyzed for three stress-related hormones: cortisol (C), beta-endorphin (BE), and testosterone (T). Behaviors were recorded with overhead video cameras. Compared to pre-exposure levels, T did not change during or following exposure to either treatment. However, BE concentrations increased (P<.05) during FRUS treatment but not during CTRL. Following return to the housing pen, cortisol levels were elevated over pre-exposure concentrations for both treatments (CTRL, P<.04; FRUS, P<.06). Analysis of the post-exposure behaviors found that following FRUS, the boars spent less time lying down and more time standing and moving around their pen (P<.05) than following CTRL. In summary, these results indicate that increased BE levels and decreased time spent lying down may be associated with the stress of frustration in the boar. Furthermore, C and T changes were not useful for differentiating between CTRL conditions and frustration.