Effect of Dietary Fish Oil Replacement with Plant Oils on Growth Performance and Gene Expression in Juvenile Rainbow Trout (Oncorhynchus mykiss)

Abstract

Growth performance [specific growth rate (SGR), weight gain (WG), food conversion ratio (FCR) and survival rate (SR)], growth hormones [growth hormone (GH-I), insulin-like growth factor-I (IGF-I) and insulin-like growth factor-II (IGF-II)], immune transforming growth factor-β (TGF-β) and antioxidant [superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT) and glutathione S-transferase (GST)] response, and heat shock protein 70 (HSP70) mRNA levels were determined in muscle and liver. Our data indicated that final weight, weight gain, FCR and SGR showed significant difference among the six dietary treatments (P<0.05) while there were no significant differences in survival rate between the rainbow trout from supplement fed groups and control group. HSP70 mRNA level expression in muscle was higher in fish fed SSO (P<0.05) while highest level in liver was obtained from fish fed SBO compared to the other treatments (P<0.05). There were no significant differences among treatments for TGF-β mRNA expression level in muscle and liver. In conclusion, growth performance and expression levels of growth hormones, antioxidants, HSP70, except TGF-β were affected by five separate lipid sources. In addition, LO positively increased growth performance of juvenile rainbow trout by means of preventing oxidative stress and HSP70 and, enhanced expression of growth hormone related gene.

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“…In our study, feeding diets containing 50-50 SO-LO had no any adverse effect on growth rate and feed conversion ratio, compared with fish fed completely fish oil diet. A similar result was obtained by Kutluyer et al (2017). In a previous study, Arslan et al (2012) found that Brown trout (Salmo trutta) fed with diets including a blend of soybean and linseed oils for 6 weeks had the greatest growth performance.…”

Utilization of grape seed oil as a dietary lipid source in rainbow trout (Oncorhynchus mykiss) diets

“…Considering the lack of statistical differences in FI values among rainbow trouts fed different experimental diets, different results in FCR might be attributed to a lower digestibility of D4 and D5 due to their higher levels in GO. When considering the range of FCR values obtained under the present study in rainbow trout (1.26 -1.54), these results may be slightly higher than those found in other studies conducted in rainbow trout (Caballero et al 2002;Kutluyer et al 2017;Yıldız et al 2018). Our results may be attributed to the larger size of the experimental fish, rearing conditions and/or different diet formulation.…”

“…Biosynthesis of LC-HUFA has been deeply investigated in fish, and it has been shown that many freshwater species are able to convert dietary LA and LNA to HUFA, such as EPA, DHA and arachidonic acid (ARA; 20:4n-6) (Tocher 2003). Although several studies on freshwater fish have reported that FO can be successfully replaced by different VOs without affecting growth performance in fish (Kutluyer et al 2017;Nayak et al 2017;Ayisi et al 2018;Yıldız et al 2018, among others), the inclusion of VOs in aqua-feeds affects the nutritional quality of the fish by modifying the fatty acid composition of the flesh with an increase in LA and LNA and a decrease in n-3 HUFA (Turchini et al 2009;Tocher 2010). The above-mentioned changes in the fillet fatty acid profile may be restored by means of the use of finishing diets at the end of the ongrowing phase prior to fish harvest (Glencross et al 2003;Trushenski and Boesenberg 2009) The grape (Vitis vinifera) is one of the world's largest fruit crops (Maier et al 2009).…”

Effects of alternative dietary oils on immune response, expression of immune‐related genes and disease resistance in juvenile Nile tilapia,Oreochromis niloticus

“…The results from this study agree to these previous reports with the replacement of FO and are contrary to findings on decrease in final growth and SGR (Montero et al, ; Ganga et al, ). The best growth performances obtained in fish fed 3FCO agree with Lin and Shiau () because the FAs were essentially synthesized from their high α‐linolenic acid (ALA; 18:3n3) and also the presence of 18: n9 makes it the preferred substrate for energy production (Kutluyer et al, ; Peng et al, ). While this study agrees to the notion that saturated FAs could be utilized efficiently by tilapia (Han et al, ; Ng et al, ; Peng et al, ), the total replacement of FO with VCO was contrary to these reports and instead, consistent with other previous studies (Szabό et al, ; Yildirim‐Aksoy et al, ).…”