Dietary supplementation with chia polyphenols alleviates oxidative stress and improves egg nutritional quality in Japanese quails under heat stress.

Heat stress in poultry is a major concern, especially in regions with hot summers and scarce cooling infrastructure. Dietary supplementation with antioxidants, such as polyphenols, has risen as a strategy to mitigate the physiological consequences of heat stress. A by-product of the extraction of oil from chia seeds, which is discarded if not used, could be a possible source of polyphenols. The aim of the present study was to evaluate the effects of dietary supplementation with polyphenols from defatted chia seed cake on the general performance, and oxidative status of Japanese quail exposed to heat stress. Furthermore, productive performance, egg quality and yolk fatty acid composition were also assessed. A total of 36 females (96 days of age) were randomly assigned to different diets: BASAL (control), LDCP (low dose of chia polyphenols), or HDCP (high dose of chia polyphenols). Half the animals in each diet group were exposed to 34 °C for 9 h a day (Heat Stress; HS), while the other half remained at the standard 24 °C (No Heat Stress; NHS). After 23 days of experimental conditions, animals under HS showed higher body temperatures and time spent panting, but lower egg laying rate. Moreover, HS modulated the activity of catalase and glutathione peroxidase enzymes, increasing lipid peroxidation in serum and liver; and increased saturated fatty acids in egg yolk. Supplementation with chia polyphenols helped to mitigate the HS effects, especially on glutathione peroxidase activity, decreasing lipid peroxidation. In addition, supplementation with HDCP showed the highest proportion of polyunsaturated fatty acids in liver and egg yolk. In conclusion, the use of defatted chia seed cake could represent a sustainable strategy to mitigate heat stress effects on Japanese quail, due to its capacity to decrease oxidative stress and improve the nutritional quality of egg, while decreasing the amount of waste generated by the food industry.

Short- and long-term dynamics of the physiological and behavioral response to heat stress and thymol supplementation in Japanese quail.

Organisms have evolved endogenous timing systems that enable them to predict temporal changes and to coordinate complex internal processes. However, temporal dynamics of biological responses are most often ignored in fields such as dietary supplementation of farm animals exposed to artificial environmental challenges. Herein, we hypothesized that the potential for thymol (2-isopropyl-5-methylphenol) to alleviate physiological and behavioral consequences of heat stress is time-dependent on both long-term (i.e. weeks) and short-term (i.e. within day) time scales. First, during 3-weeks adult female Japanese quail (Coturnix japonica) were exposed daily to 9h of increased environmental temperature (34.2 ± 0.1 °C). Controls remained at standard temperatures (23.6 ± 0.1 °C). Simultaneously, half received thymol dietary supplementation and the other half a control basal diet. On day 4, both thymol and heat stress decreased body weight and feed intake respect to controls (basal, standard temperature). After three weeks, feed intake recovered for thymol groups. Therefore, we performed a second experiment focused on the critical first week of treatment, sampling variables three times a day. The beneficial effects of thymol supplementation were mainly observed during the morning, including prevention of high respiratory rates and reduction in the weight of droppings induced by heat stress, and increased walking under both temperatures. In summary, thymol's potential for alleviating heat stress consequences is time-dependent, and can be conceived as an emergent property resulting from the complex interplay between the dynamics of the biological response to thymol and heat stress. Findings highlight the importance of considering time-related factors when developing supplementation protocols to mitigate environmental challenges.

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

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.