Feed Ingredients For Aquaculture Research Articles

Solar cultivation of microalgae in a desert environment for the development of techno-functional feed ingredients for aquaculture in Qatar

The demand for aquaculture feed will increase in the coming years in order to ensure food security for a growing global population. Microalgae represent a potential fish-feed ingredient; however, the feasibility of their sustainable production has great influence on its successful application. Geographical locations offering high light and temperature, such as Qatar, are ideal to cultivate microalgae with high productivities. For that, the environmental and biological interactions, including field and laboratory optimization, for solar production and application of two native microalgae, Picochlorum maculatum and Nannochloris atomus, were investigated as potential aquaculture feed ingredients. After validating pilot-scale outdoor cultivation, both strains were further investigated under simulated seasonal conditions using a thermal model to predict light and culture temperature cycles for the major climatic seasons in Qatar. Applied thermal and light variations ranged from 36 °C and 2049 μmol/m2/s in extreme summer, to as low as 15 °C and 1107 μmol/m2/s in winter, respectively. Biomass productivities of both strains varied significantly with maximum productivities of 32.9 ± 2.5 g/m2/d and 17.1 ± 0.8 g/m2/d found under moderate summer conditions for P. maculatum and N. atomus, respectively. These productivities were significantly reduced under both extreme summer, as well as winter conditions. To improve annual biomass productivities, the effect of implementation of a simple ground heat exchanger for thermal regulation of raceway ponds was also studied. Biomass productivities increased significantly, during extreme seasons due to respective cooling and heating of the culture. Both strains produced high amounts of proteins during winter, 54.5 ± 0.55% and 44 ± 2.25%, while lipid contents were high during summer reaching up to 29.6 ± 0.75 and 28.65 ± 0.65%, for P. maculatum and N. atomus respectively. Finally, using acute toxicity assay with zebra fish embryos, both strains showed no toxicity even at the highest concentrations tested, and is considered safe for use as feed ingredient and to the environment.

Biodiversity of the intestinal microbiota of black tiger prawn, Penaeus monodon, increases with age and is only transiently impacted by major ingredient replacement in the diet

Substitution of aquaculture feed ingredients to reduce reliance on capture fisheries may affect gut microbiome and resilience to environmental stress. To investigate replacement protein sources in feeds for black tiger prawn, Penaeus monodon, three isonitrogenous, isoenergetic diets were tested in a randomised blind trial using fisheries by-product meal, cattle and poultry by-product meal and soybean meal as the major protein. Juvenile P. monodon (1.46 ± 0.28 g, 24 per tank, 4 tanks per treatment) were acclimatised on reference diet for 2 weeks, weighed, then fed experimental diets for two weeks. Elevated temperature, pH and salinity was applied for a further two weeks. Feed conversion ratio was significantly higher in animals fed soybean meal-based diet (F (2,9) = 21.7, p < 0.001). To determine any effect of diet on intestinal microbiome the V6-V8 region of the 16s rRNA gene was sequenced on arrival from the farm, at the end of acclimatisation, 24 h after starting test feeds, after 2 weeks on test feeds and after stress period. We found no significant effect of diet on alpha diversity of the midgut microbiota, and no correlation between stress resilience, diet and gut microbiome diversity. However, time had a significant impact on beta diversity throughout the experiment across all three diets (p < 0.001), with the most abundant genera on arrival from the farm being from the genera Photobacterium and Vibrio while the relative abundance of members of the Rhodobacteraceae, Pseudoalteromonadaceae, Mycoplasmataceae and Flavobacteriaceae increased throughout the trial and were also found in the seawater supply. Changing only the protein in the diet is not sufficient to impact gut microbiome, even when animal growth and feed conversion is severely compromised by the diet. We found that time/age is the major driver of intestinal microbiome changes in P. monodon, with diversity increasing as the animal ages.

Insect-Based Feed Ingredients for Aquaculture: A Case Study for Their Acceptance in Greece.

Simple SummarySince 2017, insects can be used as ingredients in aquafeeds in the EU. However, insect-based aquafeeds are still not broadly accepted by European aquaculture companies. Understanding the beliefs of people associated with the aquaculture sector on the use of insect-based fish diets could assist their adoption. In the present study, we ran a survey among the participants of an aquaculture conference held in Greece, in order to ask them what they think regarding the inclusion of insect meal in aquafeeds. Furthermore, we inquired nine Greek aquaculture and aquafeed companies about this issue. Greece is among the largest farmed fish producers in the EU; however, there are currently no data available on the acceptance of insect-based aquafeeds in Greece. Based on our results, the majority of the respondents were aware and in favor of the inclusion of insects in aquafeeds, mainly due to their potential to lower fishing pressure on wild fish stocks used for fishmeal production and enhance the ecological footprint and sustainability of aquaculture. Moreover, six out of nine companies were favorably disposed towards the use of insects in fish diets and four of them were willing to produce or use such diets. Further studies are warranted towards this direction.Although the inclusion of insects in fish diets is officially allowed in the EU since 2017, insect-based aquafeeds have not been widely adopted by the European aquaculture sector. In order to investigate the perceptions related with adoption trends, it is critical to explore the beliefs of people associated with the aquaculture sector on the use of insects in farmed fish diets. A survey was conducted among 228 participants of an aquaculture conference to explore their perceptions on the inclusion of insect meal in fish diets. Additionally, we investigated the attitudes of nine companies operating in the aquaculture and aquafeed sector in Greece that attended the conference towards this direction. The findings of the conference survey provide evidence that there is a wide-range awareness and acceptance regarding the use of insect-based feeds in farmed fish diets among the respondents. This is mainly driven by the expectations for the decline in fishing pressure on wild fish stocks, the reduction of the ecological footprint and the enhancement of the sustainability of the aquaculture sector. The results of the stakeholder survey show that six out of the nine companies that participated in the survey are favorably disposed towards the use of insect-based feeds. Specifically, four of them stated that they would produce or use aquafeeds based on insects. However, the results highlight the need for further research on the implementation of the wider adoption of insect-based feeds in aquaculture. The present study provides some first insights into the use of insect-based aquafeeds in Greece, for which there are no data available.

Effects of full replacement of dietary fishmeal with insect meal from Tenebrio molitor on rainbow trout gut and skin microbiota

BackgroundAquaculture must continue to reduce dependence on fishmeal (FM) and fishoil in feeds to ensure sustainable sector growth. Therefore, the use of novel aquaculture feed ingredients is growing. In this regard, insects can represent a new world of sustainable and protein-rich ingredients for farmed fish feeds. Accordingly, we investigated the effects of full replacement of FM with Tenebrio molitor (TM) larvae meal in the diet of rainbow trout (Oncorhynchus mykiss) on fish gut and skin microbiota.MethodsA feeding trial was conducted with 126 trout of about 80 g mean initial weight that were fed for 22 weeks with two isonitrogenous, isolipidic, and isoenergetic extruded experimental diets. Partially defatted TM meal was included in one of the diets to replace 100% (TM 100) of FM, whereas the other diet (TM 0) was without TM. To analyse the microbial communities, the Illumina MiSeq platform for sequencing of 16S rRNA gene and Qiime pipeline were used to identify bacteria in the gut and skin mucosa, and in the diets.ResultsThe data showed no major effects of full FM substitution with TM meal on bacterial species richness and diversity in both, gut mucosa- and skin mucus-associated microbiome. Skin microbiome was dominated by phylum Proteobacteria and especially by Gammaproteobacteria class that constituted approximately half of the bacterial taxa found. The two dietary fish groups did not display distinctive features, except for a decrease in the relative abundance of Deefgea genus (family Neisseriaceae) in trout fed with insect meal. The metagenomic analysis of the gut mucosa indicated that Tenericutes was the most abundant phylum, regardless of the diet. Specifically, within this phylum, the Mollicutes, mainly represented by Mycoplasmataceae family, were the dominant class. However, we observed only a weak dietary modulation of intestinal bacterial communities. The only changes due to full FM replacement with TM meal were a decreased number of Proteobacteria and a reduced number of taxa assigned to Ruminococcaceae and Neisseriaceae families.ConclusionsThe data demonstrated that TM larvae meal is a valid alternative animal protein to replace FM in the aquafeeds. Only slight gut and skin microbiota changes occurred in rainbow trout after total FM replacement with insect meal. The mapping of the trout skin microbiota represents a novel contribution of the present study. Indeed, in contrast to the increasing knowledge on gut microbiota, the skin microbiota of major farmed fish species remains largely unmapped but it deserves thorough consideration.

Global adoption of novel aquaculture feeds could substantially reduce forage fish demand by 2030

With the global supply of forage fish at a plateau, fed aquaculture must continue to reduce dependence on fishmeal and oil in feeds to ensure sustainable sector growth. The use of novel aquaculture feed ingredients is growing, but their contributions to scalable and sustainable aquafeed solutions are unclear. Here, we show that global adoption of novel aquafeeds could substantially reduce aquaculture’s forage fish demand by 2030, maintaining feed efficiencies and omega-3 fatty acid profiles. We combine production data, scenario modelling and a decade of experimental data on forage fish replacement using microalgae, macroalgae, bacteria, yeast and insects to illustrate how reducing future fish oil demand, particularly in high-value species such as salmonids, will be key for the sustainability of fed aquaculture. However, considerable uncertainties remain surrounding novel feed efficacy across different life-cycle stages and taxa, and various social, environmental, economic and regulatory challenges will dictate their widespread use. Yet, we demonstrate how even limited adoption of novel feeds could aid sustainable aquaculture growth, which will become increasingly important for food security. Novel aquaculture feeds are rapidly developing, but their contributions to sustainable industry growth are unknown. Cottrell et al. model feed efficiency and fatty acid profiles, showing that replacing forage fish with novel feed ingredients could strengthen aquaculture’s role in global food security.

Bi-objective optimization of tuna protein hydrolysis to produce aquaculture feed ingredients

Fish meal is commonly employed as protein source in aquaculture diets. The enrichment of this ingredient with fish protein hydrolysates (FPH) and free amino acids has proved to improve larval development and feed assimilation. In this work, we produced tuna head hydrolysates using a sequential enzymatic treatment employing Alcalase and Flavourzyme. Statistical modelization coupled with bi-objective optimization were employed to optimize the operating parameters (i.e. pH, temperature and duration of the Flavourzyme treatment) for producing a FPH with a desired molecular weight profile. More specifically, this work focused on the content of small peptides between 700–2500Da (F2500) and that of free amino acids (F250), supported by their benefits as aquaculture feed ingredients.The optimal reaction conditions for maximimizing the release of free amino acids F250 (i.e, pH 7.2, 43–49°C, Flavourzyme treatment above 160min) were detrimental for the content of F2500. A bi-objective optimization approach was then proposed, able to find a set of intermediary solutions (Pareto Front) presenting maximal F2500 for a range of free amino acids level between 2–30%. This allows the selection of the operating parameters for producing a FPH with a desired weight profile, based on the specific needs of the farmed species.

Potentiality of new feed ingredients for aquaculture: A review

The continuous demand for alternative protein sources for fish due to its short supply, high prices and competition with the human food. A review of unconventional feeds in fish nutrition was carried out to provide information on supplemental feed for effective Aquaculture. Non-conventional dietary energy and protein sources,especially from plant origin can be used to replace expensive protein sources. There is a continuous demand for alternative protein sources for fish due to short supply, cereals and oilseed mealsfor sustainable aquaculture production. The solid waste materials like distillers dried grain soluble, breweries waste, ghee residue and agricultural plant materials like jute, leucaena, moringa, cassava, rain tree and spirulina can find a place in formulation of aquafeed as one of the inexpensive feed ingredients. The non-conventional feed ingredients to be incorporated in fish feed up to recommended levels.

Evaluation of fish protein hydrolysates in juvenile African catfish (Clarias gariepinus) diets

Fish protein hydrolysates (FPH) were used in a feeding trial with juvenile African catfish Clarias gariepinus, to determine their effects on growth and feed utilisation, and impact on non-specific immune function and body composition, at varying dietary inclusion levels. Fish processing by-products were enzymatically hydrolysed to a degree of hydrolysis of 16%, and included at 4 dietary levels: 10 g kg−1, 19 g kg−1, 28 g kg−1 and 38 g kg−1 dry matter, respectively substituting 5%, 10%, 15% and 20% of dietary fish meal. The FPH had high protein content (763 g kg−1 on dry weight basis), of which a high proportion consisted of essential amino acids (417 g kg−1 protein). Feeding trial results indicated that all diets supported high specific growth rates of 4.72–5.09% day−1, and final animal weight, weight gain, specific growth rate, feed conversion ratio, and animal condition factor were unaffected by dietary FPH inclusion. Apparent dry matter digestibility was also not affected by FPH inclusion. Inclusion of 19 g kg−1 FPH resulted in higher (P < 0.05) serum immunoglobulin levels compared to the control, while total protein and lysozyme levels remained unaffected. FPH also affected body composition, resulting in lower (P < 0.05) moisture for all FPH treatments compared to the control, and higher (P < 0.05) lipid levels except at 28 g kg−1 inclusion. In conclusion, the FPH represents a nutritious feed ingredient which can be utilised in juvenile African catfish diets up to 38 g kg−1 inclusion without affecting growth, feed utilisation or condition factor. The FPH exhibited bioactivity through significantly enhanced immunoglobulin levels at an intermediate inclusion level of 19 g kg−1. The work demonstrates that FPH can have a dual effect when included in aquaculture diets, as it can act as nutritious feed ingredient effectively replacing a portion of dietary fish meal, while simultaneously improving components of the non-specific immune function. The work is further relevant in that it clearly demonstrates the possibility of utilising by-products not destined for fish meal production, for production of aquaculture feed ingredients. It therefore contributes to sustainable utilisation of natural resources, and the improvement of aquaculture feeding practices.

Embodied Resources in Fish and Shrimp Feeds

AbstractGlobal averages were obtained for amounts of energy, land, water, wildfish, nitrogen, and phosphorus embodied in aquaculture feed ingredients. These data allowed amounts of these embodied resources to be calculated for typical feed formulations for channel catfish, Ictalurus punctatus; hybrid catfish, I. punctatus♀ × I. furcatus♂; Vietnamese catfish, Pangasius spp.; Atlantic salmon, Salmo salar; rainbow trout, Oncorhynchus mykiss; tilapia, Oreochromis spp.; whiteleg shrimp, Litopenaeus vannamei; and black tiger shrimp, Penaeus monodon. Embodied resource use per m.t. of feed varied among species: energy, 4.90–12.48 GJ/m.t.; land, 0.082–0.312 ha/m.t.; water, 502–1227 m3/m.t.; wildfish, 0–2880 kg/m.t.; nitrogen, 3.08–8.63 kg/m.t.; phosphorus, 1.16–5.62 kg/m.t. These calculations did not account for variations in site‐specific factors related to embodied resources and feed composition and use. But they suggest that reducing feed conversion ratio (FCR) by 0.1 unit for the seven species (species groups) could potentially reduce feed use by around 1.1 million tonne (Mt) while conserving 9.8 million GJ of energy, 270,000 ha of agricultural land, 1.4 billion m3 of freshwater, and 1.24 Mt of wildfish. Reduction of the FCR is a powerful means of lessening farm‐level production costs and negative impacts of feed production and use.

The values of whole algae and lipid extracted algae meal for aquaculture

This research applies hedonic pricing methods to value whole algae and lipid-extracted algae (LEA) for aquaculture. Prices and nutritional characteristics for commonly applied aquaculture feed ingredients are used to determine the values of whole algae and LEA based on their nutrient compositions. The results show that whole Chlorella pyrenoidosa will have a higher value than soybean meal and a lower value than menhaden fishmeal. Results show that whole Nannochloris oculata and N. oculata LEA will have a lower value than both soybean meal and menhaden fishmeal.