Dietary Thymol Supplementation Promotes Antioxidant Responses and Thermal Stress Resistance in Rainbow Trout, Oncorhynchus mykiss

Global warming is an important issue in the context of climate change affecting cold-water aquaculture. Heat stress induces oxidative stress in fish, hence the use of a functional diet supplemented with antioxidant additives, such as thymol, can be useful to counteract the impact of global warming on aquaculture. In this study, we used thymol-enriched diets to rear rainbow trout fingerlings over an 8-week period followed by a period of heat stress of 48 h. Although thymol had no significant benefits on the growth and innate immunity of the fish, it improved antioxidant capacity and reduced lipid peroxidation and mortality after heat stress. The appropriate thymol dose for these benefits is 100 mg/kg. © 2024 by the authors.