Thymol supplementation effects on adrenocortical, immune and biochemical variables recovery in Japanese quail after exposure to chronic heat stress

NAZAR, F. N.; VIDELA, E. A.; MARIN, R. H .

ANIMAL

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2019 vol. 13 p. 318 - 325

1751-7311

Chronic heat stress (CHS) exposure negatively impairs avian?immunoneuroendocrine interplay. Thymol has shown several bioactive propertiesincluding antioxidant, bactericidal, antifungal and GABA modulator activities.Indeed, supplementationwith thymol has been used with positive effects on poultry production andimmune related variables. This study evaluates whether a thymol dietarysupplementation can be used as a new functional feed strategy to mitigate CHSdeleterious effects on endocrine, biochemical and immune related variables. Starting at 100 days ofage, 24 fully adult Japanese quail were fed with a diet supplemented withthymol (≈80mg/quail/day) and other 24 quail remained non-supplemented (control diet).Between 119 and 127 days of age, half of the quail within those groups weresubmitted to a CHS by increasing environmental temperature from 24ºC to 34ºCduring the light phase and the other half remained at 24°C (non-stressedcontrols). Three days after CHS ended (during the recovery period), corticosterone,albumin, total proteins and globulins and glucose concentrations, inflammatoryresponse, antibody production and Heterophil to Lymphocyte (H/L) ratio wereassessed. No differences between groups were found in basal corticosteroneconcentrations. Total proteins, total globulins and glucose concentrations werefound elevated in the previously CHS group compared to their control counterparts.Regardless of the previous CHS exposure, thymol supplementation increasedalbumin concentrations and inflammatory responses, and decreased antibody titers.An interaction between thymol supplementation and prior CHS exposure was foundon the H/L ratio. Quail previously exposed to CHS and supplemented with thymolshowed similar H/L values than their control non-stressed counterparts,suggesting that thymol has a stress preventive effect on this variable. Thepresent findings together with the already reported thymol bioactiveproperties, suggest that feed supplementation with this compound could be auseful strategy to help overcoming some of the CHS induced alterations