Immune-neuroendocrine phenotypes and their social stress modulation in laying hens.

NAZAR, F. N.; ESTEVEZ I.; CORREA S. G.; MARIN R. H.

Louisville

Congreso; 2015 Poultry Science Association Annual Meeting; 2015

Immune, nervous and endocrine system studies in superior vertebrateshave led to the description of immune-neuroendocrine phenotypes (INP),implying subgroups within a population differing on immune-neuroendocrine(INE) interactions. In mammals, INP are well representedby the Fisher/Lewis paradigm in rats. Moreover, the phenotypes havebeen associated with differences in the physiology of stress response.We proposed for the first time the existence of INPs in an avian speciesstudying a Japanese quail population. To evaluate whether this biologicalphenomenon generalizes to other avian, we assessed the existenceof INPs in Hy-line Brown laying hens. Two hen subsets with oppositeprofiles were found showing consistent results with previous studies inquail and mammals as follows: Lewis-like hens (16% of the hens studied)showed lower corticosterone basal levels associated with higher lymphoproliferativeresponse, plasma interferon-γ and interleukin-4 levels andlower antibody titter against SRBC and innate/acquired leukocytes ratiothan their Fischer-like hen counterparts (also 16% of the birds). Thus,the already observed INP phenomenon in mammals and quail appearto generalize to a new avian species that has a much greater productiverelevance, and more interestingly, that has been intensely manipulatedthrough a long history of selective breeding. Findings suggest that ata population level, hens are prepared to deal with a wide spectrum ofINE challenges. This study also evaluated whether a social chronicstress disturbance modulates the individuals? INE interplay affectingthe proportions and distribution of the proposed INP. After stress, sameindividuals showing either Lewis- or Fischer-like INP retained theirprevious INE interplay. Nevertheless, an increase of about 13% in thosedivergent INP frequencies (polarized effect) was found at the expense ofa reduction in the number of hens showing intermediate INE responses.The increased frequency in polarized INP induced by chronic stresscould represent an underlying population strategy to maximize survival.