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FEATURE

Nutraceutics for the control of bacterial coldwater disease by C. Fernández-Álvarez, Facultad de Biología (CIBUS), Y. Torres-Corral, Facultad de Biología (CIBUS), G. Coscelli, Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, Argentina, A. R. Sánchez-Arévalo, Lípidos Toledo S.A; Madrid, Spain, A. Martínez, Lípidos Toledo S.A; Madrid, Spain, M.I. Quiroga, Facultad de Veterinaria, Universidad de Santiago de Compostela, Spain, Y. Santos, Facultad de Biología (CIBUS)

T

he aquaculture industry has developed significantly over recent decades and is, today, one of the fastest-growing food production sectors in the world. One of the most important problems that affect aquaculture is the appearance of infectious diseases. Among bacterial diseases affecting cultured salmonid fish, Bacterial Cold-Water Disease, caused by Flavobacterium psychrophilum, produces high mortality and morbidity and consequently, economical losses worldwide. Attempts to control this situation through the use of antimicrobials have been limited due to the rapid appearance of antibiotic-resistant bacteria. Moreover, the determinants of antibiotic resistance that have emerged and selected in this aquatic environment have the potential of being transmitted by horizontal gene transfer to bacteria of the terrestrial environment, including human and animal pathogens. Evidence indicating that antibiotic-resistant bacteria and antibiotic resistance determinants pass from the

aquatic to the terrestrial environment has resulted in a drastic restriction of the use of antibiotics in aquaculture in many countries. For this reason, it is important to find new products with antimicrobial activity without the aforementioned undesirable effects of antibiotics. In this sense, natural food additives or phytobiotics, which combined different mechanisms of action against pathogenic bacterial species (bactericidal/ bacteriostatic activities, Quorum Sensing inhibition), are potential candidates for the development of prevention strategies in aquaculture. This work describes

the effect of the dietary administration to rainbow trout of the phytobiotic Liptofry (Liptosa S.A, Spain) in the improvement of disease resistance against Flavobacterium psychrophilum. In this study 4000 healthy rainbow trout, distributed in two experimental groups (2000 individuals/each) were maintained in an aquaculture facility of the north of Spain, until its transfer to the aquarium of the Faculty of Biology of the University of Santiago de Compostela. Rate of food supply of both groups was established based on the requirements of the fish, taking as a reference the parameters of size and weight of the specimens and the temperature of the water. • Group 1: Fish fed with feed supplemented with the phytobiotic Liptofry manufactured by Lípidos Toledo SA (Liptosa SA, Spain). • Group 2: Fish fed with no supplemented feed (control fish). The usefulness of feeding the fish with diet supplemented with phytobiotics in the prevention of Bacterial cold-water disease (BCWD) in rainbow trout was determined by

14 | INTERNATIONAL AQUAFEED | November-December 2015

Nov | Dec 2015 International Aquafeed  

The November - December 2015 edition of International Aquafeed magazine