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- Hinchcliffe, James, 1992, et al.
(författare)
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Comparative survival and growth performance of European lobster Homarus gammarus post-larva reared on novel feeds
- 2020
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Ingår i: Aquaculture Research. - : Hindawi Limited. - 1355-557X .- 1365-2109. ; 51:1, s. 102-113
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Tidskriftsartikel (refereegranskat)abstract
- One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by-products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post-larval lobsters from post-larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze-dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven-dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring-based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non-heat-treated shrimp products are a promising feed ingredient for post-larval European lobsters.
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| 2. |
- Warwas, Niklas, et al.
(författare)
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Marine yeast (Candida sake) cultured on herring brine side streams is a promising feed ingredient and omega-3 source for rainbow trout (Oncorhynchus mykiss)
- 2023
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 571
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Tidskriftsartikel (refereegranskat)abstract
- A major challenge for the aquaculture industry is the supply of sustainable feeds. A promising model to achieve this is to utilize circular flows where feed ingredients, such as single cell protein, are cultivated using side streams of the food industry. The aim of this study was to evaluate the marine yeast Candida sake, produced on herring brine side streams, as a source of protein and immune stimulant in feed for salmonid fish. The dry C. sake product contained 54% protein (3.3% lysine and 0.8% methionine) and 13% lipids (1.1% eicosapentaenoic, EPA, and 1% docosahexaenoic acid, DHA). Four experimental diets were designed and tested in a 9-week feeding trial using juvenile rainbow trout (Oncorhynchus mykiss). A control diet containing both fish and plant-based ingredients constituted the base feed to which 20% (to evaluate effects on digestibility, growth and intestinal physiology), 20% heat-treated (to evaluate effects of downstream processing) and 3% (to evaluate immune stimulatory properties, replacing 3% soy protein concentrate) C. sake was added. The apparent digestibility coefficient of C. sake for protein, fat and gross energy was above 80%, and for amino acids above 90% regardless of treatment, suggesting a high bioavailability of C. sake. All three yeast containing diets performed equally to the control regarding specific growth rate, feed conversion ratio and functional intestinal health. These results suggest that C. sake is a promising alternative protein source for circular feeds in the salmonid industry. The presence of EPA and DHA represents an added value. The heat treatment increased the apparent digestibility coefficient of dry matter by 8% but decreased amino acid digestibility by on average 3%, indicating that heat treatment may not be the optimal downstream processing technique. Furthermore, the inclusion of 3% C. sake increased the intestinal lamina propria width and TGF-beta transcription, indicating an immune stimulating effect. Future research is needed to understand these immune modulatory effects of C. sake supplementation.
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