Insights into thermal stress in Japanese quail (Coturnix coturnix): dynamics of immunoendocrine and biochemical responses during and after chronic exposure

NAZAR, F. N.; VIDELA, E. A.; FERNANDEZ M. E.; LABAQUE, M. C.; MARIN, R. H .

STRESS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2018

1025-3890

Avians require comfortable temperatures for optimal development and heatstress is a high concern in warm weather countries. We aimed to assess thedynamics of immunoendocrine and biochemical variables responses of birdsexposed to a heat stressor applied during daylight hours, during both thechronic stress and the recovery periods. We hypothesize that variables involvedin the birds´ response will be differentially and gradually modified during thoseperiods. Female quail (N=210) were housed in 6 rearing boxes. At 29 days ofage, the temperature in 3 boxes was increased from 24°C to 34ºC during thelight period throughout 9 days (Stress treatment). The other 3 boxes remainedat 24°C and were used as controls. The subsequent 12 days were considered asrecovery period. Different sets of 12 birds/treatment were blood-sampled at 29(basal), 32, 35, 38 (stress), 41, 44, 47, and 50 (recovery) days of age. Immunoendocrine(corticosterone, lymphoproliferation, heterophil/lymphocyte ratio (H/L) andantibody response) and biochemical (glucose, total proteins, globulins and albumin)variables were assessed. During stress, progressive corticosterone and H/L increments,and antibody titers and lymphoproliferation decreases were detected. No clearpattern of changes was found in biochemical variables. During recovery, while corticosteroneand lymphoproliferation had recovered 3 days after the stressor ended, H/L and antibodyresponses required respectively 9 and 12 days to recover basal levels. Findingssuggests that immunity is already threatened when heat stress is sustained for3 or more days. However, the system appears resilient needing 6 to 12 day torecover basal responses