RT Journal Article
T1 Fasting Meets the Forecast: Thermal Conditions Influence Post-Mortem Muscle Traits in Rainbow Trout (Oncorhynchus mykiss)
A1 Martínez Villalba, Andrea
A1 De la Llave-Propín, Álvaro
A1 Fuente Vázquez, Jesús De La
A1 González De Chávarri Echániz, Elisabeth
A1 Díaz Díaz Chirón, María Teresa
A1 Fernández-Muela Garrote, Montserrat
A1 Cabezas Albéniz, Almudena
A1 González Garoz, Roberto
A1 Villarroel, Morris
A1 Bermejo Poza, Rubén
AB In aquaculture, pre-slaughter fasting reduces stress and improves muscle quality. Fasting periods of 55–58 degree days (°C d) enhance muscle structure and post-mortem biochemistry in rainbow trout (Oncorhynchus mykiss), although optimal durations vary with temperature. This study investigated the effects of fasting from none to extended durations on 495 rainbow trout under summer (22 °C) and winter (8 °C) conditions. In summer, elevated temperatures increased muscle glycogen, leading to lower pH and delayed rigor mortis (RM), especially in fasted groups, where RM peaked at 24 h post-mortem. In winter, RM occurred earlier. Prolonged fasting increased acetylcholinesterase (AChE) activity, with high baseline levels in non-fasted summer fish. Muscle lightness at 0 h post-mortem was highest in non-fasted winter fish but declined to summer levels in fasted groups. Antioxidant enzyme activity (glutathione-S-transferase, glutathione peroxidase) increased with fasting in winter, while summer heat masked responses. The expression of genes for mineralocorticoid receptors and heat shock proteins remained stable in warm conditions. Summer delayed metabolic decline due to higher glycogen-triggered excessive AChE activity from heat stress. Winter supported faster metabolic adjustment and more regulated enzyme activity. These findings highlight the need to adjust fasting strategies seasonally to optimize muscle traits, especially under thermal variations.
PB MDPI
YR 2025
FD 2025
LK https://hdl.handle.net/20.500.14352/122766
UL https://hdl.handle.net/20.500.14352/122766
LA eng
NO Martínez Villalba, A.; De la Llave-Propín, Á.; De la Fuente, J.; González de Chavarri, E.; Díaz, M.T.; Fernández-Muela, M.; Cabezas, A.; González-Garoz, R.; Villarroel, M.; Bermejo-Poza, R. Fasting Meets the Forecast: Thermal Conditions Influence Post-Mortem Muscle Traits in Rainbow Trout (Oncorhynchus mykiss). Fishes 2025, 10, 267. https://doi.org/ 10.3390/fishes10060267
NO Justificación de autores:Conceptualization, J.D.l.F., M.T.D., M.F.-M., M.V. and R.B.-P.; methodology, A.M.V., Á.D.l.L.-P., E.G.d.C., A.C. and R.G.-G.; validation, R.B.-P., J.D.l.F. and M.V.; investigation, A.M.V.; data curation, A.M.V. and R.B.-P.; writing—original draft preparation, A.M.V.; writing—review and editing, Á.D.l.L.-P., J.D.l.F., E.G.d.C., M.T.D., M.F.-M., A.C., R.G.-G., M.V. and R.B.-P.; supervision, J.D.l.F. and R.B.-P.; funding acquisition, J.D.l.F. All authors have read and agreed to the published version of the manuscript
NO Ministerio de Agricultura, Pesca y Alimentación (España)
DS Docta Complutense
RD 17 dic 2025