Olive Pomace and Soybean-Sunflower Acid Oils as Alternative Fat Sources in European Seabass (<i>Dicentrarchus labrax</i>) Diets: Effects on Performance, Digestibility and Flesh Fatty Acid Composition and Quality Parameters

Abstract

The effects of dietary inclusion of soybean-sunflower and olive pomace acid oils on growth, digestibility and flesh composition were studied in European seabass. Eight diets were fed for 100 days (101.37 ± 0.33 g initial weight, mean ± SD), differing in the added fat source (25% fish oil, 75% experimental oil): S (crude soybean oil), SA (soybean-sunflower acid oil), O (crude olive pomace oil) or OA (olive pomace acid oil); 3 blends: S-O, S-OA, SA-OA at a 1:1 ratio; and a diet containing only fish oil (F) as a control. Animals fed OA showed the worst performance among dietary treatments, with the lowest weight, specific growth ratio, average daily gain and the highest feed conversion ratio (p p > 0.05), but a lower digestibility of lipids and saturated fatty acids was observed (p p > 0.05). Hence the results suggest that the studied acid oils may potentially be used in fish diets although further studies are needed.

Keywords

• acid oil
• free fatty acid
• fat by-product
• alternative energy source
• dietary fat
• flesh quality