González Garoz, RobertoCabezas Albéniz, AlmudenaMartínez Villalba, AndreaGonzález De Chávarri Echániz, Elisabethde la Llave-Propín, ÁlvaroVillarroel, MorrisFernández-Muela Garrote, MontserratFuente Vázquez, Jesús De LaBermejo Poza, RubénDíaz Díaz Chirón, María Teresa2025-10-222025-10-222025González-Garoz, R., Cabezas, A., Martínez Villalba, A., González De Chávarri, E., De La Llave-Propín, Á., Villarroel, M., Fernández-Muela, M., De La Fuente, J., Bermejo-Poza, R., & Díaz, M. T. (2025). Stunning techniques and climatic influence in rainbow trout: Sensibility state, welfare and recovery ability. The Veterinary Journal, 314, 106459. https://doi.org/10.1016/j.tvjl.2025.1064591090-023310.1016/j.tvjl.2025.106459https://hdl.handle.net/20.500.14352/125261Credit authorship contribution statement: Gonzalez Garoz Roberto: Writing – original draft, Methodology, Data curation. María Teresa Díaz: Writing – review & editing, Validation, Supervision, Data curation, Conceptualization. Ruben ´ BermejoPoza: Writing – review & editing, Conceptualization. Jesús De la Fuente: Writing – review & editing, Supervision, Funding acquisition, Conceptualization. Montserrat Fernandez-Muela: ´ Writing – review & editing, Methodology. Morris Villarroel: Writing – review & editing, Supervision, Funding acquisition, Conceptualization. Alvaro ´ de la Llave-Propín: Writing – review & editing, Methodology. Elisabet Gonzalez ´ de Chavarri: ´ Writing – review & editing, Methodology. Andrea Martínez Villalba: Writing – review & editing, Methodology. Almudena Cabezas: Writing – review & editing, MethodologyThis study evaluated the effects of climatic conditions and three stunning techniques on the stress response, sensibility state, and recovery ability of rainbow trout (Oncorhynchus mykiss). Stunning methods included ice-water immersion (ICE) and two electric shock treatments combined with ice-water immersion (E200: 200 mA for 2 s; E400: 400 mA for 0.5 s followed by 200 mA for 1.5 s). Rainbow trout were exposed to these methods in winter and summer to assess the impact of seasonality. Under winter conditions, fish in the ICE group retained sensibility, whereas electrically stunned fish lost sensibility rapidly and remained insensible for an extended period. In summer, the ICE group exhibited a gradual loss of sensibility, while fish in both the E200 and E400 groups became immediately insensible post-stunning. Blood cortisol levels were significantly higher in the ICE group, indicating a stronger stress response, whereas electrically stunned fish had lower cortisol levels, likely due to their immediate loss of sensibility. Markers of carbohydrate and lipid metabolism also reflected an intensified mobilization during summer, highlighting the influence of seasonal variation. Regarding recovery ability, winter conditions promoted higher recovery rates across all groups, with over 50 % of fish regaining sensibility. In contrast, electrically stunned fish in summer demonstrated lower recovery rates, suggesting potential irreversibility of the stunning effect, while ice-water immersion preserved recovery ability. These findings underscore the substantial impact of climatic conditions on stunning effectiveness and fish welfare in rainbow trout, emphasizing the importance of adjusting stunning techniques according to seasonal temperature changesengAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal article1532-2971https://doi.org/10.1016/j.tvjl.2025.10645941046070open access639.3Climatic conditionsElectric stunningIce-water immersionRainbow troutRecovery abilitySensibilityStunningPiscicultura3105.02 Piscicultura