Event Abstract

Back to Event

Evaluation of defatted krill meal as partial and total fishmeal replacement in diets for gilthead seabream (Sparus aurata) juveniles

Sara Moutinho1, 2*, Silvia Martínez-Llorens3, Ana Tomás-Vidal3, Miguel Jover-Cerdá3, Aires Oliva-Teles1, 2, 4 and Helena Peres1, 2
  • 1 Centro Interdisciplinar de Pesquisa Marine e Ambiental (CIIMAR), Portugal
  • 2 Centro Interdisciplinar de Pesquisa Marine e Ambiental (CIIMAR), Portugal
  • 3 Universitat Politècnica de València, Institute of Animal Science and Technology, Spain
  • 4 Faculdade de Ciências, Universidade do Porto, Departamento de Biologia, Portugal

With the increase in marine aquaculture production, there is an underlined demand for high quality protein sources for aquafeeds. Fish meal (FM) has been regarded as the ideal protein source for carnivorous fish but the growing pressure on fish stocks and little prospect of increasing production limits its availability for aquafeed production (FAO, 2016). Therefore, further growth of carnivorous fish production must rely on new and more sustainable feed resources becoming available. Antarctic krill (Euphausia superba) is considered to be the organism with the largest biomass worldwide and is harvested as a source of bioactive compounds such as pigments, chitin, and essential fatty acids with importance for food, feed, and medical purposes (Tibbetts et al., 2011). For aquafeeds, krill has enormous potential as it possesses a nearly ideal amino acid profile for carnivorous marine species, substantial amounts of essential omega-3 fatty acids, and has olfactory and gustatory stimulatory substances. Dietary krill meal inclusion has been evaluated for a few fish species (Storebakken, 1988; Yoshitomi et al., 2006; Gong et al., 2016) but due to lack of economic feasibility of krill fisheries and problems with processing, krill is only scarcely used for fish feeds. In general, krill oil is extracted from dried krill powder using organic solvents where the fraction containing soluble lipids is separated from the remaining residue. After drying, this residue has a high protein content and can be used in food products, protein supplements, and animal feeds at a competitive price (Saebo et al., 2016). Gilthead seabream (Sparus aurata) is a fish with great economic importance in Mediterranean aquaculture. Yet, overproduction in the last decades has had a negative toll on the main European markets (Martínez-Llorens et al., 2012). Since feeding can account for more than half of total production costs, it is necessary to find new strategies to improve production profitability. Given this, the aim of this study was to evaluate the potential of defatted krill meal (KM) as partial or total replacement of FM in diets for gilthead seabream juveniles. To do so, four extruded diets (44% protein; 21% lipids) were formulated: a control diet (KM0) containing FM as the only protein source, and three diets where FM protein was replaced by KM at 33% (KM33), 66% (KM66), and 100% (KM100). Triplicate groups of 45 fish (initial body weight of 24 g) were fed the experimental diets for 12 weeks in a thermo-regulated (22.5 ºC) seawater system. Growth performance, nutrient, and amino acid retentions and digestive enzymes activities were evaluated. At the end of the feeding trial, growth performance linearly decreased with the dietary inclusion of KM. In addition, feed intake was compromised when FM was fully replaced by KM, but feed efficiency and protein efficiency ratio were not affected by diet composition. Nitrogen retention (% intake) was not affected by KM inclusion, while energy retention (% intake) was lower in fish fed diet KM100 compared to the control. Whole-body composition was not affected by dietary treatment except for energy content that was lower in fish fed the diet KM33 than the control. Similarly, whole body amino acid profile and EAA retention (% intake) remained similar among dietary treatments. No differences were observed in the activity of the digestive enzymes with the substitution of FM by KM. Overall, present results indicate that FM replacement with KM compromised growth performance, though not affecting feed efficiency or digestive enzymes activity. Further evaluation is required to understand which nutritional aspects of KM may have negatively affected its nutritional value for gilthead sea bream juveniles. In particular, chitin, which is found at high levels in crustacean exoskeleton, may have compromised the bioavailability of nutrients or led to changes in metabolic or physiological responses, and this needs to be carefully evaluated in future studies.

References

FAO (2016). "The State Of World Fisheries And Aquaculture 2016: Contributing To Food Security And Nutriton For All", (ed.) Food and Agriculture Organization of the United Nations (FAO). (Rome).

Gong, Y.-y., Huang, Y.-q., Gao, L.-j., Lu, J.-x., Huang, H.-l., and Xia, Y.-t. (2016). Substitution of Krill meal for Fish Meal in Feed for Russian Sturgeon, Acipenser gueldenstaedtii. The Israeli Journal of Aquaculture - Bamidgeh 68, 1319-1325.

Martínez-Llorens, S., Baeza-Ariño, R., Nogales-Mérida, S., Jover-Cerdá, M., and Tomás-Vidal, A. (2012). Carob seed germ meal as a partial substitute in gilthead sea bream (Sparus aurata) diets: Amino acid retention, digestibility, gut and liver histology. Aquaculture 338-341, 124-133. doi: 10.1016/j.aquaculture.2012.01.029.

Saebo, A., Myhren, F., and Hoem, N. (2016). Lipid extraction processes. United States patent application 15/040,330.

Storebakken, T. (1988). Krill as a potential feed source for Salmonids. Aquaculture 70, 193-205. doi: 10.1016/0044-8486(88)90096-8.

Tibbetts, S.M., Olsen, R.E., and Lall, S.P. (2011). Effects of partial or total replacement of fish meal with freeze-dried krill (Euphausia superba) on growth and nutrient utilization of juvenile Atlantic cod (Gadus morhua) and Atlantic halibut (Hippoglossus hippoglossus) fed the same practical diets. Aquaculture Nutrition 17(3), 287-303. doi: 10.1111/j.1365-2095.2010.00753.x.

Yoshitomi, B., Aoki, M., Oshima, S.-i., and Hata, K. (2006). Evaluation of krill (Euphausia superba) meal as a partial replacement for fish meal in rainbow trout (Oncorhynchus mykiss) diets. Aquaculture 261(1), 440-446. doi: 10.1016/j.aquaculture.2006.06.036.

Keywords: Marine aquaculture, novel feed ingredients, sustainability, by-products, defatted krill meal

Conference: IMMR'18 | International Meeting on Marine Research 2018, Peniche, Portugal, 5 Jul - 6 Jul, 2018.

Presentation Type: Poster Presentation

Topic: Aquaculture

Citation: Moutinho S, Martínez-Llorens S, Tomás-Vidal A, Jover-Cerdá M, Oliva-Teles A and Peres H (2019). Evaluation of defatted krill meal as partial and total fishmeal replacement in diets for gilthead seabream (Sparus aurata) juveniles. Front. Mar. Sci. Conference Abstract: IMMR'18 | International Meeting on Marine Research 2018. doi: 10.3389/conf.FMARS.2018.06.00142

Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.

The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.

Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.

For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.

Received: 29 Apr 2018; Published Online: 07 Jan 2019.

* Correspondence: Ms. Sara Moutinho, Centro Interdisciplinar de Pesquisa Marine e Ambiental (CIIMAR), Matosinhos, 4450-208, Portugal, smoutinho@ciimar.up.pt