Age matters: differential effects of the exposure to elevated environmental temperatures on representative variables of the immune system in juvenile and adult female Japanese quail.

VIDELA, E. A.; TORTONE, S.; MARIN R. H.; NAZAR, F N

JOURNAL OF THERMAL BIOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2022

0306-4565

Severaldays under the influence of high environmental temperature negatively impact onsome immune-related variables of poultry species. However, little is knownwhether this exposure affects differentially the immune response on different lifestages. This study was aimed at characterizing the immune responses of femalejuvenile and adult Japanese quail when exposed to a cyclic chronic heat stressor.Independent sets of juveniles (24) and adults (21) female Japanese quail werebred under thermoneutral conditions or exposed to an increasing temperaturefrom 24°Cto 34°C,for eight hours along nine consecutive days (chronic heat stressor). Theinflammatory response against a mitogen, the antibody production against anon-pathogenic antigen and the heterophil to lymphocyte (H/L) ratio weremeasured after the ninth day of chronic heat exposure. Adult females had a morerobust inflammatory response compared to their juvenile counterpart. Theinflammatory response, the production of antibodies, and the H/L ratio weresuppressed by the chronic heat stressor in the juvenile females; while in theiradult counterpart, the production of antibodies was not affected by the chronicheat stress. Under the exposure of high environmental temperatures, female juvenileswould be more susceptible to potentially harmful pathogens that require arobust immune response; while their adult counterparts would be able to mountan optimal acquired immune response against pathogens requiring this type of response.Our findings suggest that while heat stress during breeding should be avoidedin both juvenile and adult females, more precautions should be taken duringearly life stages.