Evaluation of ingredient combinations from differing origins (fishmeal, terrestrial animal and plants) and two different formulated nutrient targets on rainbow trout growth and production efficiency

In a 7-week on-farm feeding trial rainbow trout (Oncorhynchus mykiss) were provided with a diet containing 28% mechanically de-fatted insect meal prepared from larvae of the black soldier fly, Hermetia illucens (HIM) and compared to a control that received a certified organic and fishmeal based diet. In the test diet insect meal replaced almost 50% of the fishmeal. The whole experiment was conducted under practical conditions on an organically certified rainbow trout farm in Switzerland. Fish of initially 66.5±2.3 g body weight were grown to 125±4.5 g and assessed for their growth performance, as well as analysed for their proximate composition, feed conversion ratio, fatty acid contents and organoleptic properties. Improved lipid utilisation and decreased protein utilisation were observed in fish fed the HIM diet. Furthermore, in a controlled degustation no differences except a slightly darker coloration of fish fed HIM were observed. The experiment demonstrated that substantial replacement of fishmeal by insect meal is possible without compromising growth, feed conversion and product quality. However, the decreased protein utilisation efficiency in HIM fed fish might lower production efficiency when applied over a whole production cycle and not only over 7 weeks.

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Cultural Energy Use and Energy Use Efficiency of a Small-Scale Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792) Cage Farm in the Inland Waters of Turkey: A Case Study from Karacaören-I Dam Lake

Aquaculture Studies ◽

10.4194/2618-6381-v21_1_04 ◽

2020 ◽

Vol 21 (1) ◽

pp. 31-39

Author(s):

Gürkan Diken ◽

Hayati Köknaroğlu ◽

İsmail Can

Keyword(s):

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Production Efficiency ◽

Energy Use ◽

Total Weight ◽

Small Scale ◽

Inland Waters ◽

Energy Use Efficiency ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Use Efficiency

The purpose of this study was to assess cultural energy (CE) use and energy use efficiency of a commercial small scale rainbow trout (Oncorhynchus mykiss) cage farm in the inland waters in Karacaören Dam Lake, Isparta, Turkey. Data collected for each production year were: number and total weight of fingerlings, amount of feed consumed, amount of antibiotics, vitamin, labor, diesel, oxygen used, number and total weight of marketed trout, distance for transportation of fingerlings, machinery, and equipment with their depreciation rate. Total CE use was the sum of CE expended on feed, general management, transportation, machinery, and equipment. CE expended on compound diet constituted 77.78% of total CE. CE expended for a kg of liveweight gain was 2.68 Mcal. Protein energy production efficiency in carcass and fillet was 4.28 and 7.44 Mcal, respectively. CE energy use efficiency for carcass and fillet were 4.19 and 6.85, respectively. Results showed that in order to compare the sustainability of aquaculture production systems energy use efficiency which is an indicator of sustainability should be determined.

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Sustainable plant-based diets promote rainbow trout gut microbiota richness and do not alter resistance to bacterial infection

Animal Microbiome ◽

10.1186/s42523-021-00107-2 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

David Pérez-Pascual ◽

Ana Elena Pérez-Cobas ◽

Dimitri Rigaudeau ◽

Tatiana Rochat ◽

Jean-François Bernardet ◽

...

Keyword(s):

Rainbow Trout ◽

Gut Microbiota ◽

Bacterial Infection ◽

Growth Performance ◽

Ecological Impact ◽

Farmed Fish ◽

Fish Food ◽

Promising Alternative ◽

Terrestrial Animal ◽

Gut Microbiota Composition

Abstract Background Farmed fish food with reduced fish-derived products are gaining growing interest due to the ecological impact of fish-derived protein utilization and the necessity to increase aquaculture sustainability. Although different terrestrial plant proteins could replace fishmeal proteins, their use is associated with adverse effects. Here, we investigated how diets composed of terrestrial vegetal sources supplemented with proteins originating from insect, yeast or terrestrial animal by-products affect rainbow trout (Onchorynchus mykiss) gut microbiota composition, growth performance and resistance to bacterial infection by the fish pathogen Flavobacterium psychrophilum responsible for frequent outbreaks in aquaculture settings. Results We showed that the tested regimes significantly increased gut bacterial richness compared to full vegetal or commercial-like diets, and that vegetal diet supplemented with insect and yeast proteins improves growth performance compared to full vegetal diet without altering rainbow trout susceptibility to F. psychrophilum infection. Conclusion Our results demonstrate that the use of insect and yeast protein complements to vegetal fish feeds maintain microbiota functions, growth performance and fish health, therefore identifying promising alternative diets to improve aquaculture’s sustainability.

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