Effects of total replacement of dietary fish oil by vegetable oils on growth performance, nutritional quality and fatty acid profiles of rainbow trout (Oncorhynchus mykiss) at optimum and high temperature conditions

Abstract

The present study investigated the effects of total replacement of dietary fish oil by different vegetable oils on growth performance, nutritional quality and fatty acid profiles of rainbow trout (Oncorhynchus mykiss) at optimum and high temperature conditions. Five iso-nitrogenous and iso-lipidic diets including 100% fish oil and vegetable oils were prepared for rainbow trout fingerlings with an average weight of 11.27±0.01 g. After the fish were fed experimental diets for 9 weeks at the optimum temperature (17.74±0.01°C), all groups were fed an FO diet containing only fish oil for 4-weeks at the upper optimum temperature conditions (19.28±0.11°C). In both feeding trials, experimental fish were hand-fed ad libitium twice a day. Results showed that growth performance and feeding efficiency were significantly better (p<0.05) in groups fed by VO-based diets compared to groups fed by FO based diet at optimum temperature. Survival was 100% in CANO, SFO, CO PNO groups and 94.12±3.39% in FO (control) group at the end of the 9 weeks. Growth, feed consumption and survival of fish fed the upper-optimum temperature were significantly differed (p<0.05). In particular, while the survival rate of the groups fed with vegetable oil-based diets at optimum temperature and then fed only fish oil remained 100%, this rate decreased to 54.17±1.39% in the control group. Eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3) and n-3 PUFA of fish fed by VO based diets were low. When all groups were fed only FO diet for 4 weeks at upper-optimum temperatures, EPA, DHA and n-3 PUFA ratios increased. In addition, after the upper-optimum temperature trial, increases in the nutritional quality indices of fish meat were also detected.

Effects of glutamine on growth performance, nutrient content, fatty acid profile, and blood parameters of rainbow trout (Oncorhynchus mykiss)

“…The study reported that the HSI values varied between 0.33 and 0.53, whereas the VSI values ranged from 11.06 to 12.23 (Keshavanath & Renuka, 1998). In a study conducted by Dernekbaşı (2012), the impact of varying ratios of canola oil added to the meal on HSI and VSI values in rainbow trout was investigated. The results indicated that HSI values ranged from 0.80% to 1.04%, whereas VSI values ranged from 10.03% to 11.99%.…”

Modelling the impact of replacing fish oil with plant oils: A meta‐analysis to match the optimal plant oil for major cultured fish

“…Eventually, 328 articles were included in this research (Figure 1) and their detailed information is stored in Table S1. Among all the included articles, 73 were conducted on Oncorhynchus mykiss , 4,23,38–108 67 were about Salmo salar , 109–175 36 were for Oreochromis niloticus , 176–211 27 investigated Sparus aurata ,…”

“…Eventually, 328 articles were included in this research (Figure 1) and their detailed information is stored in Table S1. Among all the included articles, 73 were conducted on Oncorhynchus mykiss, 4,23, 67 were about Salmo salar, 36 were for Oreochromis niloticus, 27 investigated Sparus aurata, 21 used Dicentrarchus labrax, 14 focused on Epinephelus spp. [260][261][262][263][264][265][266][267][268][269][270][271][272][273] and the remaining 90 articles were on other species with lower report frequency.…”

“…However, some researchers have found that environmental factors such as water temperature play critical roles in aquaculture, 22 and could massively impact the results of replacing fish oil with plant oils. Dernekbasi et al found that Rainbow trout previously fed with sunflower and peanut oil grow much faster than the fish oil group when fed the same diet under high‐temperature conditions, 23 while Bowyer et al reported that canola oil only reduced the growth of rainbow trout in cold water but not in warm water 24 . On the other hand, the impacts of plant oils might be related to fish size and duration of the experiment, but exact association patterns were barely discussed.…”