Meeting Abstract
It has now been well established that animals with reactive versus proactive personalities also show differences in hormonal responses to stress. Reactive animals produce larger amounts of corticosterone when compared with proactive animals after stress exposure. We know less, however, about whether other physiological variables that change after stress exposure differ between personality types. In addition to corticosterone elevations, stressors also provoke a suite of other physiological changes, including redistributions of circulating white blood cells and the production of heat shock proteins (HSPs). In fact, it has been proposed that elevations in the levels of HSPs may be a more effective measure of long-term stress exposure.. Brown and white laying hens are excellent models of these two personality types: white layers are reactive and display high corticosterone responses to stress while brown hens are proactive and produce low levels of corticosterone after stress exposure. We predict that white and brown hens will also display differences in white blood cell distributions and levels of HSPs. Thus, the objective of this study was to determine whether brown and white hens differ in their alteration of heterophil lymphocyte (H:L) ratios and production of HSP-60, 70, and 90 in response to stress exposure and corticosterone elevations. Hens were exposed to food restriction, or were provided corticosterone in water for ten days. Control birds were given no treatment. We predicted that treatment will increase H:L ratios and HSP expression in both strains with white layers showing a greater response to treatment than brown layers. Results will be discussed.
