1Instituto de Ciencia y Tecnología de los Alimentos (ICTA),Facultad de Ciencias Exactas, Físicas y Naturales,Universidad Nacional de Córdoba (UNC),Córdoba X5000JJC,Argentina.
Animal. 2019 Feb;13(2):318-325. doi: 10.1017/S175173111800157X. Epub 2018 Jul 9.
Chronic heat stress (CHS) exposure negatively impairs avian' immunoneuroendocrine interplay. Thymol has shown several bioactive properties including antioxidant, bactericidal, antifungal and gamma-aminobutyric acid modulator activities. Indeed, supplementation with thymol has been used with positive effects on poultry production and immune-related variables. This study evaluates whether a thymol dietary supplementation can be used as a new functional feed strategy to mitigate CHS deleterious effects on endocrine, biochemical and immune-related variables. Starting at 100 days of age, 24 fully adult Japanese quail were fed with a diet supplemented with thymol (≈80 mg/quail per day) and other 24 quail remained non-supplemented (control diet). Between 119 and 127 days of age, half of the quail within those groups were submitted to a CHS by increasing environmental temperature from 24°C to 34°C during the light phase and the other half remained at 24°C (non-stressed controls). A period of 3 days after CHS ended (during the recovery period), corticosterone, albumin, total proteins and globulins and glucose concentrations, inflammatory response, antibody production and heterophil to lymphocyte (H/L) ratio were assessed. No differences between groups were found in basal corticosterone concentrations. Total proteins, total globulins and glucose concentrations were found elevated in the previously CHS group compared with their control counterparts. Regardless of the previous CHS exposure, thymol supplementation increased albumin concentrations and inflammatory responses and decreased antibody titers. An interaction between thymol supplementation and prior CHS exposure was found on the H/L ratio. Quail previously exposed to CHS and supplemented with thymol showed similar H/L values than their control non-stressed counterparts, suggesting that thymol has a stress preventive effect on this variable. The present findings together with the already reported thymol bioactive properties, suggest that feed supplementation with this compound could be a useful strategy to help overcoming some of the CHS induced alterations.
慢性热应激（CHS）暴露会对禽类的免疫神经内分泌相互作用产生负面影响。百里香酚具有多种生物活性特性，包括抗氧化、杀菌、抗真菌和γ-氨基丁酸调节剂活性。事实上，百里香酚的补充已被用于对家禽生产和免疫相关变量产生积极影响。本研究评估了百里香酚的饮食补充是否可以作为一种新的功能性饲料策略，以减轻 CHS 对内分泌、生化和免疫相关变量的有害影响。从 100 日龄开始，24 只完全成年的日本鹌鹑被喂食补充了百里香酚（≈80mg/只/天）的饮食，另外 24 只鹌鹑则喂食未补充的对照饮食。在 119 到 127 日龄之间，这些组中的一半鹌鹑的环境温度从 24°C 升高到 34°C（在光照阶段），另一半鹌鹑则保持在 24°C（非应激对照）。在 CHS 结束后（恢复期）的 3 天内，评估了皮质酮、白蛋白、总蛋白和球蛋白、葡萄糖浓度、炎症反应、抗体产生以及异嗜白细胞与淋巴细胞（H/L）比值。在基础皮质酮浓度方面，两组之间没有差异。与对照组相比，之前经历过 CHS 的组中的总蛋白、总球蛋白和葡萄糖浓度升高。无论之前是否经历过 CHS 暴露，百里香酚补充都会增加白蛋白浓度和炎症反应，降低抗体滴度。在 H/L 比值方面发现了百里香酚补充和之前 CHS 暴露之间的相互作用。之前暴露于 CHS 并补充了百里香酚的鹌鹑的 H/L 值与未应激的对照组相似，这表明百里香酚对该变量具有应激预防作用。这些发现与百里香酚的已报道生物活性特性一起表明，用这种化合物进行饲料补充可能是一种有用的策略，可以帮助克服一些由 CHS 引起的改变。
