Stress coping in japanese quail: could chronic stress and environmental enrichment be opposite forces affecting immunity?

NAZAR FRANCO NICOLÁS; ARBELO, DARÍO C; MARÍN RAÚL HÉCTOR

Congreso; IX Congreso de Ornitología Neotropical y VII Congreso Peruano de Ornitología.; 2011

Conservation of animals many times requires captivity, manipulation and other stressful situations. Reproduction in captivity is nowadays an option for the recovery of threatened species. Stressful situations lead to stress responses as a manifestation of the animals attempt to cope with new circumstances. Stress is an adaptive response but if sustained in time may have detrimental consequences and could lead to failures in animals’ adaptation to new environments. This study evaluates whether an environmental enrichment (EE) manipulation can modulate avian immune responses and if combined with a chronic stressor exposure can help counteract stress negative effects on the immune system. Potential gender effects were also considered. After hatch, half of the birds were housed in environmentally enriched boxes and half were housed in non-enriched boxes. From day 33 to 42 of age, all birds within half of the enriched and non-enriched boxes remained undisturbed while the other half were daily exposed to a 15 min restraint stressor (chronic stressor). The inflammatory response (lymphoproliferative), percentage of lymphocytes, heterophil/lymphocyte (H/L) ratio and primary antibody response against sheep red blood cell were assessed. The chronic stressor application and the EE procedure respectively either increased or reduced the 4 immunological parameters evaluated and always in opposite directions. Males consistently showed lower antibody titers than females and presented the highest H/L ratio in response to the stressor when reared in the non- enriched environment. The findings suggest that submitting the animals to an enriched environment can be effectively used as a positive modulator of the immune response and to reduce the detrimental effects of a stressor exposure. Taking this into consideration could be a useful tool for improving conservation plans of captive animals, leading to a better cope of new situations, and probably improving conservation results.