RT Journal Article
T1 Using Underwater Currents as an Occupational Enrichment Method to Improve the Stress Status in Rainbow Trout
A1 Martinez-Villalba, Andrea
A1 De la Llave-Propín, Alvaro
A1 Fuente Vázquez, Jesús De La
A1 Pérez Marcos, Concepción
A1 González De Chávarri Echániz, Elisabeth
A1 Díaz Díaz Chirón, María Teresa
A1 Cabezas Albéniz, Almudena
A1 González-Garoz, Roberto
A1 Torrent, Fernando
A1 Villarroel, Morris
A1 Bermejo Poza, Rubén
AB This study investigated the effects of occupational enrichment, specifically underwater currents, on the stress status of rainbow trout (Oncorhynchus mykiss). A total of 540 fish were divided into three groups: control tanks without artificial currents (CO), tanks with randomly fired underwater currents (RFC), and tanks with continuous current throughout the day (CT). After 30 days, half of the fish in each group underwent a 5-day pre-slaughter fasting (5D), while the others were fed until the day before slaughter (0D). Fish in the RFC group exhibited lower levels of plasma cortisol and acetylcholinesterase enzyme activity in hypothalamus and optic tract than other groups, suggesting an improved stress status. RFC group also showed higher levels of non-esterified fatty acids (NEFA) in 5D fish and higher liver glycogen stores, suggesting improved energy reserves. In comparison, the CT group had higher LDH levels, possibly due to their increased swimming activity. The CO group had significantly lower NEFA levels at 5D compared to the RFC group, suggesting lower energy reserves. The RFC fish had darker and yellow-reddish skin and liver color, suggesting an improved stress status and lower lipid reserves, respectively. Overall, although a significant stress response was not observed in fasted individuals, possibly due to the relatively short fasting period, the study suggests that providing occupational enrichment using randomly fired underwater currents for 1 month helped to improve stress status in rainbow trout, indicating that occupational enrichment during the grow-out phase can positively impact the welfare of rainbow trout during routine handling procedures.
PB Springer
SN 0920-1742
YR 2023
FD 2023
LK https://hdl.handle.net/20.500.14352/98606
UL https://hdl.handle.net/20.500.14352/98606
LA eng
NO Villalba, A.M., De la Llave-Propín, Á., De la Fuente, J. et al. Using underwater currents as an occupational enrichment method to improve the stress status in rainbow trout. Fish Physiol Biochem (2023). https://doi.org/10.1007/s10695-023-01277-3
NO Universidad Complutense de Madrid 
DS Docta Complutense
RD 23 jul 2024