Self-selection of diets with different oil oxidation levels in gilthead seabream ( Sparus aurata)

• Published in: Aquaculture 2011-04, Vol.314 (1), p.282-284
• Main Authors: Montoya, A., Martins, D. Alves, Yúfera, M., Sánchez-Vázquez, F.J.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal aquaculture; Animal behavior; Animal productions; Animal, plant and microbial ecology; Biological and medical sciences; Diet; fasting; Fish; fish oils; food choices; Fundamental and applied biological sciences. Psychology; General aspects; Gilthead seabream; lipid peroxidation; Lipids; Marine; minerals; Oxidation; oxidative stress; Oxidized lipids; Sea water ecosystems; self-feeders; Self-feeding; soybean oil; Sparus aurata; Synecology; vitamins
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2011.01.041

The present research looked at the ability of gilthead seabream to discriminate between two similar diets differing only in the extent of lipid oxidation. Six groups of 4 fish (254 g initial wet weight) were allowed to be selected by means of self-feeders between two complete diets (34.5% casein + gelatin, 14.8% fish oil + soybean oil, 24.8% dextrin and 25.9% vitamins, minerals, filler and binder) which differed only in the oxidation level of the lipid source: 6.2 meq/kg for the control (D1) and 100.0 meq/kg for the oxidized diet (D2). During the first nine days of the trial, fish took similar amounts of D1 and D2, although there was a clear tendency to gradually avoid D2. Finally, on day 10 fish demanded a significantly higher percentage (82%) of D1. When the diets were interchanged to investigate feeder preferences, two selection patterns were observed: three groups resumed their selection for D1 from day 7 onwards, while the other three groups did not show a clear preference for any diet until they were subjected to a 3-week fasting period (which boosts internal oxidation), after which they significantly selected D1. Taking together the results before and after fasting, gilthead seabream were able to discriminate and avoid a diet with oxidized lipids, and the physiological state of fish (oxidative stress caused by fasting) appeared to reinforce their selection/avoidance behavior.