Chronic stress and environmental enrichment as opposite factors affecting the immune response in Japanese quail

NAZAR, F. N.; MARIN, R. H.

STRESS

TAYLOR & FRANCIS LTD

Año: 2011 vol. 14 p. 166 - 173

1025-3890

Procedures in the commercial production of animals involve stressful situations which lessen the animal?s welfare. This study evaluates whether an environmental enrichment manipulation can affect avian immune responses and if combined with a chronic stressor exposure can help counteract the negative effects of stress on the immune system. Pontential gender effects were also considered. After hatch, half of the birds were housed in non-enriched boxes and half were housed in environmentaly enriched boxes. From day 33 to 42 of age, all birds within half of the non-enriched and enriched boxes remained undisturbed while the other half were daily exposed to a 15 min restraint stressor (chronic stressor). The inflammatory response (lymphoproliferative to phytohemagglutinin-p), percentage of lymphocytes, heterophil/lymphocyte 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 anitbody titers than females and presented the highest heterophil/lymphocyte 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 to improve their immune response and to reduce the detrimental effects of a stressor exposure.