Total substitution of fish oil by vegetable oils in Senegalese sole (Solea senegalensis) diets: effects on fish performance, biochemical composition, and expression of some glucocorticoid receptor-related genes

Abstract

To study the substitution of fish oil by vegetable oils in fish diets, juveniles Senegalese sole (Solea senegalensis) were fed diets (56 % crude protein, 12 % crude lipid) containing either linseed (100LO) or soybean (100SO) oils in comparison with a 100 % fish oil-based diet (100FO) for 90 days. Samples of muscle, liver, and intestine were collected for biochemical analysis and for glucocorticoid receptor-related genes, including GR1 and GR2, and the associated heat shock proteins HSP70, HSP90AA, and HSP90AB. Besides, basal levels of plasma cortisol were also determined. After the feeding period, a stress test, consisting on 5 min of net chasing, was applied to a selected population of each dietary group. Total replacement of fish oil by vegetable oils did not induced changes in fish growth and performance, but affected fatty acid profile of muscle, liver, and intestine, reflecting those tissues the characteristic fatty acids of each type of dietary oil. A tendency to conserve the ARA/EPA ratio could be observed in the different tissues, despite of the level of these fatty acids in diet. Chasing stress induced an increase of muscle GR1 and a reduction in intestinal GR2 relative expressions at any of the experimental diets assayed. In liver, chasing stress induced an increase in both GR1 and GR2 gene expression in fish fed fish oil diets. Similarly, chasing stress induced an increase of muscle HSP70 and decrease of HSP90AB in liver at any of the experimental diet assayed. Besides, vegetable oils decreased the expression of HSP70 in intestine, being the relative expression of liver HSP90AA increased by the inclusion of linseed oil in the diet, at any of the experimental conditions assayed.

Partial or total replacement of dietary fish oil with alternative lipid sources in silvery-black porgy (Sparidentex hasta)

“…Data from growth performance parameters of silvery-black porgy juveniles fed diets with alternative vegetal oil sources demonstrated that the partial or total replacement of dietary FO by VO sources (CO and SO) did not compromise growth performance or feed efficiency compared to the control diet; however, a much longer trial simulating the entire on-growing period of this species may be required to validate these results under an industrial perspective. These results are consistent with previous studies showing the viability of partial or total replacing dietary FO with different VO sources in marine fish species (Turchini et al, 2009;Sales and Glencross, 2011;Nasopoulou and Zabetakis, 2012;Benítez-Dorta et al, 2013). However, regarding the use of tallow as a potential source of fat for FO substitution in diets for silvery-black porgy juveniles, presents results indicated that total or partial replacement of FO with this source of animal fat caused a reduction in 8.7-9.5% of fish growth performance.…”

Effects of alternate feeding with different lipid sources on fatty acid composition and bioconversion in European sea bass (Dicentrarchus labrax)

“…The results of this experiment indicate that canola oil has negative effect on growth performance. By contrast, numerous studies have shown that the replacement of fish oil by canola oil in aquafeed had minimal detrimental impacts on marine fish (sea bass, sea bream, Senegalese sole, Atlantic salmon) growth performance (Yıldız and Şener, 1997;Tocher et al, 2000;Torstensen et al, 2000;Montero et al, 2005;Mourente and Bell, 2006;Montero et al, 2008;Turchini et al, 2011;Eroldoğan et al, 2012;Benitez-Dorto et al, 2013;Yılmaz and Eroldoğan, 2015). However, some studies with European sea bass and Atlantic salmon (Salmo salar) have indicated that fish oil replacement with canola oil up to levels of 60-75% was possible with negative effects on fish growth (Torstensen et al, 2004;Mourente et al, 2005) In the present study, fish in FST treatment grew significantly faster than fish in AST treatment during the final finishing period.…”

Diet-Induced Fatty Acid Variation in Critical Tissues of a Spawning Estuarine Fish and Consequences for Larval Fitness

“…This observation presents a point of comparison for future studies of other animals. For example, total substitution of fish oil with vegetable oil in diets fed to a marine pleuronectiform did not affect performance as measured by response to sustained chasing stress but did influence organ and tissue FA profiles (Benítez-Dorta et al 2013). The ability of other taxa to maintain physiological performance under differing dietary FA compositions and the mechanisms behind this capacity in some fishes are unknown.…”