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

Abstract

Avian require comfortable temperatures for optimal development and heat stress is a high concern in warm weather countries. We aimed to assess the dynamics of immunoendocrine and biochemical variables responses of birds exposed to a heat stressor applied during daylight hours, during the chronic stress and the recovery periods. We hypothesize that variables involved in the birds response will be differentially and gradually modified during those periods. Female quail (n = 210) were housed in six rearing boxes. At 29 days of age, the temperature in three boxes was increased from 24 to 34 °C during the light period throughout the nine days (Stress Treatment). The other three boxes remained at 24 °C and were used as controls. The subsequent 12 days were considered as recovery 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, respectively. Immunoendocrine (corticosterone, lymphoproliferation, heterophil/lymphocyte ratio (H/L), and antibody 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 clear pattern of changes was found in biochemical variables. During recovery, while corticosterone and lymphoproliferation had recovered three days after the stressor ended, H/L and antibody responses required respectively nine and 12 days to recover to their basal levels, respectively. Findings suggest that immunity is already threatened when heat stress is sustained for three or more days. However, the system appears resilient, needing six to 12 days to recover to their basal responses.

Immediate and transgenerational effects of thymol supplementation, inactivated Salmonella and chronic heat stress on representative immune variables of Japanese quail

“…Our results, together with the previously reported differences between sexes 6,7 , indicate that males would be more susceptible to potentially harmful environmental pathogens or antigens, evidenced by an elevated H/L ratio which is indicative of increased stress response mediators concentration (the higher the values of the indicator, the higher the plasmatic mediators concentration 46,47 ). Our results agree with previous reports informing that the exposure to CHS impairs the inflammatory response against PHA-P and the H/L ratio in adult Japanese quail 11,24,33 . Regarding supplementation under thermoneutral (control) conditions, previous reports have demonstrated an enhanced inflammatory and humoral response when poultry species were supplemented with thymol or a combination of thymol and its isomer, carvacrol 34,35 .…”

“…As expected, the H/L ratio observed in the chicks remained at basal levels 24 , since they were not exposed to any environmental challenge. However, although they were not intentionally stressed, some stress responses would be expected throughout their development.…”

“…The room temperature was kept at 25 °C (comfort temperature). For habituation to the breeding 24 . Briefly, thymol was commercially obtained from Sigma-Aldrich (SAFC, ≥ 99%; FCC, Saint Louis, MO, USA).…”

“…Previous reports inform that repeated episodes of elevated environmental temperature and high levels of pathogens challenge have detrimental effects on different components of the immune system. For example, alterations in white cells structure 22 , intestinal morphology and its microbiota 23 , increments in the heterophil to lymphocyte ratio (H/L), reductions in inflammatory responses 11,24 , macrophages activity 25 and antibody mediated responses 22,25,26 have been reported for poultry species.…”

Effect of Dietary Curcumin on the Growth Performance, Serum Antioxidation and Meat Quality of Ducks (Anas Platyrhynchos)

“…Curcumin is a kind of polyphenol component occurring in turmeric rhizomes (Curcuma Longa Linn). Curcumin has been equivocally proved to possess many bene cial biological functions, such as anticoccidial [5], antiin ammatory [6], anticancer [7] and antioxidation ability protecting the cells against the lipid oxidation [1,8].…”