scholarly journals Apparent Digestibility of Macronutrients and Fatty Acids from Microalgae (Schizochytrium sp.) Fed to Rainbow Trout (Oncorhynchus mykiss): A Potential Candidate for Fish Oil Substitution

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 456
Author(s):  
Amélie Bélanger ◽  
Pallab K. Sarker ◽  
Dominique P. Bureau ◽  
Yvan Chouinard ◽  
Grant W. Vandenberg
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Fish Oil ◽  
Nutrient Digestibility ◽  
Fish Feed ◽  
Potential Candidate ◽  
Apparent Digestibility ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Aquaculture Feed

Aquaculture feed formulation has recently turned its focus to reduce the reliance on marine-derived resources and utilise alternative feedstuffs, as an approach to improve the environmental sustainability of the aquaculture sector. The fish oil market is highly volatile, and availability of this commodity is continuously decreasing for use in aquaculture. Currently, a growing number of commercial efforts producing microalgae are providing omega 3-rich oil for sustainable aquaculture feed. This study was focused to determine the nutrient digestibility of a marine microalga, Schizochytrium spp., which is rich in docosahexaenoic acid (DHA) and long-chain polyunsaturated fatty acids (LC-PUFA), as a novel dietary lipid source that could be utilized effectively by rainbow trout (Oncorhynchus mykiss). A whole-cell Schizochytrium spp. biomass was used in the digestibility experiment at two different temperatures, 8 °C and 15 °C. No significant differences were detected between the two temperatures for the apparent digestibility coefficients (ADCs) of the dry matter (94.3 ± 4.9%), total lipids (85.8 ± 0.0%), crude proteins (89.5 ± 1.8%), energy (83.1 ± 1.7%) and fatty acids (85.8 ± 7.5%). The ADCs of the nutrients, energy, DHA and other fatty acids showed that Schizochytrium spp. is a high-quality candidate for fish oil substitution and supplement of LC-PUFA in fish feed with vegetable oils.

Effect of animal and vegetal protein diets on feed intake and apparent digestibility of nutrients in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida, with and without chronic hypoxia stress

1998 ◽  
Vol 55 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
H Néji ◽  
J de la Noüe
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Feed Intake ◽  
Chronic Hypoxia ◽  
Phosphate Buffer Solution ◽  
Aeromonas Salmonicida ◽  
Animal Protein ◽  
Fish Feed ◽  
Apparent Digestibility ◽  
Rainbow Trout Oncorhynchus Mykiss

This study was undertaken to investigate the effects of bacterial infection (Aeromonas salmonicida) and chronic hypoxia on mortality, feed intake, and apparent digestibility of each of two diets in rainbow trout (Oncorhynchus mykiss). The diets were isonitrogenous (gross basis); one was based mainly on animal protein and the other on vegetal protein. In each of two separate and successive experiments, where the first served as a control for the second, fish were immersed on day 0 (d0) in either a sterile phosphate buffer solution (first experiment) or a suspension of A. salmonicida (second experiment). Thereafter, the fish were either exposed on d2 for 12 days to hypoxic conditions (60% of water oxygen saturation) or maintained under normal conditions. Feed intake was measured daily, while apparent digestibility coefficients for gross energy, dry matter, and crude protein were measured on d0, d2, d5, d9, d11, and d14. Among all infected fish, feed intakes were reduced (P < 0.05), regardless of the source of dietary protein or the degree of water oxygenation. Also, regardless of infection, the feed intakes of hypoxic fish that were fed the vegetal protein based diet were significantly less than those of fish that were fed the animal protein based diet. This response, however, was transitory, since normal levels of feed intake in the former fish were found by d3. The apparent digestibility coefficients for all parameters were unaltered by hypoxia (P > 0.05), but they were significantly reduced (P < 0.05) by A. salmonicida infection, especially during the critical period of infection (d5 and d9).

Evaluation of the composition of essential fatty acids in the tissues of rainbow trout (Oncorhynchus mykiss) grown in closed water supply units

2021 ◽  
Vol 325 (4) ◽  
pp. 495-501
Author(s):  
E.A. Zykina ◽  
M.V. Gurin
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Water Supply ◽  
Oncorhynchus Mykiss ◽  
Fish Oil ◽  
Essential Fatty Acids ◽  
The Body ◽  
Biologically Active ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Aquaculture Products

Recently, the task of artificial cultivation of especially valuable fish species in aquaculture has become more and more urgent. The value of salmon fish, and in particular rainbow trout Oncorhynchus mykiss (Walbaum, 1792) available for breeding, is largely determined by the high content of biologically active essential and polyunsaturated fatty acids of the group ω-6 and ω-3, necessary for vital activity and not synthesized by the human body. Since the natural stocks of many popular fatty fish have decreased, farmed fish can help meet consumer demand for this product. Based on this, the assessment of the content of the main ω-6 and ω-3 fatty acids in the fat of rainbow trout grown in closed-loop water supply installations (USV) was made. The fat was extracted from the fish by thermal method with further distillation by supercritical fluid extraction on the SFT-150 unit. The ratio of fatty acids in the fish oil sample was determined using the Chromatek-Kristall-5000 M hardware and software complex. The results obtained were compared with the standard for salmon fish oil “Aquaculture products” and “Wild fish”. It is established that trout cultivated in the UZV in the Penza region, in terms of the content of the main essential fatty acids, is not inferior to the quality indicators of the standard in terms of the requirements for salmon fish of “Aquaculture products”. In fish, all essential fatty acids are present in sufficient quantities, the ratio of ω-6 to ω-3 is 2.6:1, which indicates a high nutritional value of the product and allows it to be used in human food to provide the body with essential fatty acids, as well as a raw material for obtaining therapeutic and preventive products.

scholarly journals Towards sustainable and ocean-friendly aquafeeds: Evaluating a fish-free feed for rainbow trout (Oncorhynchus mykiss) using three marine microalgae species

Elem Sci Anth ◽  
2020 ◽  
Vol 8 ◽  
Author(s):  
Pallab K. Sarker ◽  
Anne R. Kapuscinski ◽  
Grant W. Vandenberg ◽  
Emilie Proulx ◽  
Alexander J. Sitek
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Fish Oil ◽  
Environmental Sustainability ◽  
Price Volatility ◽  
Marine Microalgae ◽  
Forage Fish ◽  
Crude Lipid ◽  
Rainbow Trout Oncorhynchus Mykiss

Aquaculture, the fastest growing food sector, is expected to expand to produce an additional 30 million metric tons of fish by 2030, thus filling the gap in supplies of seafood for humans. Salmonids aquaculture exploits the vast majority of fishmeal and fish oil rendered from ocean-dwelling forage fish. Most forage fish diverted to these commodities are human-food grade, and all are primary prey for marine predators. Rising costs, price volatility, and environmental sustainability concerns of using these commodities for aquaculture feed are driving the global search for alternatives, including marine microalgae originating from the base of marine food webs but produced in culture. We report the first evaluation of two marine microalgae, Nannochloropsis sp. and Isochrysis sp., for their potential to fully replace fishmeal and fish oil in diets of rainbow trout (Oncorhynchus mykiss), an important model for all salmonid aquaculture. We conducted a digestibility experiment with dried whole cells of Nannochloropsis sp. and Isochrysis sp., followed by a growth experiment using feeds with different combinations of Nannochloropsis sp., Isochrysis sp., and Schizochytrium sp. We found that digestibilities of crude protein, crude lipid, amino acids, fatty acids, omega 3 polyunsaturated fatty acids (n3 PUFA), docosahexaenoic acid (DHA), n6 (omega 6) PUFA in Isochrysis sp. were significantly higher than those in Nannochloropsis sp. Digestibility results suggest that for rainbow trout diets Isochrysis sp. is a better substitute for fishmeal and fish oil than Nannochloropsis sp. The lower feed intake by fish fed diets combining multiple microalgae, compared to fish fed the reference diet, was a primary cause of the growth retardation. In trout fillets, we detected an equal amount of DHA in fish fed fish-free diet and reference diet. This study suggests that Isochrysis sp. and Schizochytrium sp. are good candidates for DHA supplementation in trout diet formulations.

scholarly journals Graded Incorporation of Defatted Yellow Mealworm (Tenebrio molitor) in Rainbow Trout (Oncorhynchus mykiss) Diet Improves Growth Performance and Nutrient Retention

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 187 ◽  
Author(s):  
Paulo Rema ◽  
Subramanian Saravanan ◽  
Benjamin Armenjon ◽  
Constant Motte ◽  
Jorge Dias
Keyword(s):  
Body Composition ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Growth Performance ◽  
Tenebrio Molitor ◽  
Nutrient Digestibility ◽  
Protein Meal ◽  
Yellow Mealworm ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficients of dry matter, protein, fat, phosphorus, and energy. Protein, phosphorus, and energy retention significantly increased in fish fed the diets with an insect protein meal. In conclusion, the yellow mealworm protein meal could effectively replace 100% of fishmeal in the diet of juvenile rainbow trout with positive effects on its overall zootechnical performance.

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