Tag: Arctic charr

Reports

Protein requirements of Arctic charr / Protein requirement of char

Published:

01/05/2013

Authors:

Jón Árnason, Ólafur Ingi Sigurgeirsson, Jónína Jóhannsdóttir, Aðalheiður Ólafsdóttir, Joseph Ginindza

Supported by:

AVS Fund (AVS Project R10011‐10)

Protein requirements of Arctic charr / Protein requirement of char

Five different feed types with protein content from (29) 30 - 40% were given in two size groups (100 g and 600 g) in both fresh and salt water. The effects of different feeds were assessed on the basis of their effects on digestibility, weight development, daily growth (SGR), feed utilization (FCR), chemical composition of fillets (in the larger fish) and sensory evaluation. Final weight and daily growth were lowest in the fish fed the lowest protein, but no effect of protein, in excess of 37% in the feed, was found on final weight and SGR. The minimum protein requirements for growth are therefore between 33% and 38% in the feed. There was no significant difference in feed response between size groups, even though the effect of reduced protein was greater in the larger fish. It was also not possible to see a single decisive effect of salinity on the protein requirement. The protein content of the feed also did not have a decisive effect on the fillet composition or sensory evaluation of the products.

Four (five) different diets with protein varying from (29) 30 - 41% were fed ad libitum to two size groups of Arctic charr (100 gram and 600gram) in fresh‐ as well as seawater. The effect of the different diets was evaluated by digestibility, weight development, SGR, FCR, chemical composition of filet (in the bigger size groups) and sensory evaluation. The lowest final weights and SGR were found when fed the diets with lowest protein but here was no effect final weight and final weight between 38% and 41% protein in the diet, indicating that the minimum need for protein is between 33 and 38% protein in the diet . The same trend was shown in both size groups but the effect was more pronounced in the bigger fish than in the smaller fish. The results regarding size and growth were also the same in fresh‐ and seawater. The protein content in the diet did not have any marked effect on either chemical composition of filets or the sensory quality of the product.

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Reports

Arctic Charr for the niche market

Published:

01/11/2011

Authors:

Birgir Þórisson, Gísli Kristjánsson, Sigrún Elsa Smáradóttir, Ólafur Ögmundarson

Supported by:

AVS Fisheries Research Fund - Preliminary project

Arctic Charr for the niche market

This report presents the results of a preliminary project on the marketing of Icelandic farmed char in a niche market in German-speaking Europe. Information was obtained from experts in the field of marketing and sales in Germany by e-mail and telephone interviews. The report contains a SWOT analysis for possible marketing efforts in the special market. The results of the SWOT analysis facilitate an overview of each aspect so that strengths and opportunities can be utilized, while reducing the effects of weaknesses and threats. 

This report describes the results of pre ‐ project on the marketing of Icelandic farmed Arctic charr in German ‐ speaking Europe´s niche market. Information was gathered from experts in the field of marketing and sales in Germany both by e ‐ mail and interviews over phone. The report includes a SWOT analysis of the potential niche markets for Arctic charr. The results of the SWOT analysis give an overview of the current market situation for Arctic charr and strengthens the opportunities while reducing the impact of weaknesses and threats when Arctic charr is marketed.

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Reports

Coloring of Arctic charr / Coloring of charr hold

Published:

01/05/2011

Authors:

Jón Árnason, Ólafur Ingi Sigurgeirsson, Gunnar Örn Kristjánsson, Jón Kjartan Jónsson, Turid Synnøve Aas and Trine Ytrestøyl, Manfred Phiscker

Supported by:

Technology Development Fund

Coloring of Arctic charr / Coloring of charr hold

An experiment was carried out with the aim of evaluating the activity of an organic pigment, Ecotone ™, and an inorganic pigment, Lucantin® Pink, on the coloration of char meat. The effect of 25% and 30% fat in feed on the activity of the pigments was also studied. All experimental items were tested in triplicate. The mean weight of the experimental fish was 564 g at the beginning of the experiment and 1381 g at the end of the experiment after 131 days. The temperature during the experimental period averaged 8 C̊ and the salinity of the broth was 20 ‰. The digestibility of astaxanthin in Lucantin® Pink was much higher than in Ecotone ™. The difference in body color measured by different methods turned out to be much smaller, which indicates a better utilization of the color in Lucantin® Pink. Little effect on body coloration was found by different amounts of fat in the feed and this was true for both pigments. The organic dye is more expensive to buy than the inorganic one and it results in approx. 5.5 % is more expensive to dye char with Ecotone ™ compared to Lucantin® Pink. During the analysis of the color of the feed at the beginning and at the end of the experiment 16 weeks later, it was found that there was a significant loss of color from the feed and that loss appeared to be independent of the type of color.

A feeding trial was conducted to compare the pigmenting efficiency of the biological colorant Ecotone ™ containg astaxanthin and prepared from the red yeast Phaffia rhodozyma, and the synthetic colorant Lucantin® Pink in Arctic charr. Both colorants were incorporated into diets containing either 25 or 30% lipid. All treatments were run in triplicate. The initial average weight of the fish was 564 g and the final weight 1381 g after a trial period of 131 days at 8 C̊ and 20 ‰ salinity. The digestibility of astaxanthin seems to be very much dependent upon the astaxanthin source. Differences in flesh color indicate a better utilization of astaxanthin from the synthetic source (Lucantin® Pink) as compared to the biological source (Ecotone ™). There was only a minor effect of lipid content on utilization of the astaxanthin. The biological astaxanthin source is more expensive than the synthetic source, resulting in about 5,5% higher production cost of fish produced with the “organic” colorant Ecotone ™ as compared to fish produced with the synthetic source of astaxanthin (Lucantin® Pink). The astaxanthin content in all diets proved to be very unstable when the feed was stored under conditions that are common in production of Arctic charr (10 - 20 ̊C indoors). The loss of astaxanthin ranged from 21-40% and tended to be higher in diets containing Ecotone ™. Thus, it is very important to avoid high temperatures, light and oxygen during storage of the feed.

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Reports

Better utilization of water in charr farming / Efficient rearing systems for Arctic charr

Published:

01/06/2010

Authors:

Ragnar Jóhannsson, Helgi Thorarensen, Ólafur Ögmundarson

Supported by:

Technology Development Fund

Better utilization of water in charr farming / Efficient rearing systems for Arctic charr

The need for water in aquaculture is extremely high and what ultimately limits the size and production capacity of aquaculture establishments is access to hot and cold water. The aim of the project was to test a cheap and simple way to reduce water consumption in charr farming. At the beginning of the project, it was assumed that water could be used in charr farming four times better than is currently the case. However, it turned out that the water can be used seven times better. The result of this study is that it is possible to produce around seven times more biomass in aquaculture on land with the amount of water used today. The goals of the project were therefore achieved and much better. In order for this to be possible, the following things need to be kept in mind:

• It is very important to release turbidity from the water as soon as possible. Therefore, a drum filter is a necessary equipment and all the water must be filtered with each cycle of recycling. The filter should use 100 μm cloth, which cleans all particles that can reduce the efficiency of the farming system.

• There must be sufficient current in the fish tanks and it is desirable that the water exchange rate is not less than 45 minutes to ensure self-cleaning and to satisfy the oxygen demand of fish at high concentrations.

• A bio-cleaner is a necessary equipment when the recycling is greater than 0.03-0.05 L kg ‐ 1 ∙ min ‐ 1. It releases ammonia from the broth. The biocleaner used in this study has been shown to work well and its design has been patented

Aquaculture requires large volumes of water are required for aquaculture and the size and production capacity of fish farms is in most places ultimately determined by access to water and geothermal heat. The objective of this project was to reduce water requirements in Arctic charr aquaculture. Through simple reuse of water the plan was to reduce water requirements fourfold compared with standard reference values in Arctic char fish farms in Iceland. This goal was achieved and at the end the reuse was sevenfold. The conclusions of the project are that by using the same amount of water used today and with a simple reuse of it the annual increase in production of Arctic char can be sevenfold the annual production of today. But to make that possible, the following points have to be kept in mind:

• It is necessary to minimize the turbidity in the water by all means. A drum filter of 100 μm is therefore needed in the recirculation system.

• The current in the rearing system has to be sufficient and the water change ratio should not be less than 45 minutes to secure self-cleaning and to fulfill the oxygen need of the fish reared in high density.

• A bio filter is needed if the recirculation exceeds 0.03-0.05 L kg ‐ 1 ∙ min‐ 1. It phases out the ammonia in the rearing system. The bio filter used in this project has shown that it works and the design of it has a patent

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Reports

Plant raw materials in charr feed instead of fishmeal and fish oil

Published:

01/05/2008

Authors:

Jón Árnason, Ólafur Ingi Sigurgeirsson, Bjarni Jónasson, Helgi Thorarensen, Rannveig Björnsdóttir

Supported by:

AVS

Plant raw materials in charr feed instead of fishmeal and fish oil

The aim of the project was to produce cheap feed for char so that production costs can be reduced and profitability in char farming can be increased. The project consisted of testing different raw materials (especially plant raw materials) instead of fishmeal and fish oil and finding out how large a proportion of them can be in the feed. The condition for success was that the feed was healthy, utilized well by the fish and led to a growth comparable to the current farmed feed and that the feed did not have a negative effect on the quality of the product, in terms of chemical content (fatty acid, color) and physical properties (taste, color, density). Different types of feed were tested as a starter feed for charr juveniles, which is a new approach, in order to get an overview of the possible amount of different raw materials. The most interesting types of feed from those experiments were then tested in experiments on larger chars to confirm the results and to examine the effect on the quality of the products. The results of the experiments with different protein ingredients confirmed that high quality fishmeal (Superior) is a very good source of protein in feed for char. The charr's possibilities of utilizing soybean meal seem to be limited, as in the case of salmon, ie. ≤ 15% incorporation into the feed. The possible use of maize gluten meal appears to be ≤ 18% in starter feeding but could not be tested on larger fish. The reaction of char to rapeseed meal as a protein source, however, was positive and in fact better than expected considering that there has not been a good word for this raw material in feed for other salmonids. Regarding fat sources in charr feed, the results of the project show that different fat sources can be used with acceptable results. Juveniles, on the other hand, seem to have somewhat stricter requirements for fat sources than larger fish. This is especially evident in the effect on growth rate. The results of the experiments with fat sources also show that the composition of the fat source has a decisive effect on the fat composition of the fish as well as various sensory evaluation factors in the product. The main conclusion, however, is that it is possible, within certain limits, to use different fat sources in charr feed. In particular, it seems that palm oil can be used extensively.

The objective of the project was to produce economic feed for Arctic charr to decrease production cost and increase profitability in Arctic charr farming. The project investigated the possibilities of replacing fishmeal and fish oil with raw materials of plant origin, and to find out the limits for their use as feed ingredients. The criteria was that the feed should ensure maximum health, optimize utilization of feed and growth should be comparable to growth obtained by feed currently used. Neither should the feed have adverse effects on product quality, especially regarding fatty acids composition and physical properties (taste, flesh-color, texture). Effect of different raw materials was screened in start feeding trails using Arctic charr larvae. The most interesting raw material combinations were thereafter tested in trials with bigger fish in order to confirm the results of the start feeding trials and investigate the effect of the combinations on slaughter quality of the Arctic charr. The results of the trials with different protein raw materials confirmed that high quality fishmeal (Superior) is a very good protein source for Arctic charr. Arctic charr seems to have limited ability to utilize soybean meal and the inclusion should be limited to ≤ 15% in the diet, similar to the limits that are common for Atlantic salmon diets. The limits for use of Corn gluten meal in starter diets seem to be ≤ 18% but this raw material was not tested in bigger fish. The response of Arctic charr to the use of rapeseed meal as a protein source was positive and even as high inclusion as 30% in the diet did not have negative effect on growth. The main findings of the project regarding use of lipid sources is that it is possible to use different sources with reasonable effect in feed for Arctic charr. Of particular interest is the effect of palm oil. Arctic charr larvae seem to be more demanding, regarding use of lipid sources, than bigger fish. The results clearly demonstrate the effect of fatty acid (FA) composition of the lipid sources on the FA composition of the fish and it is possible to change the FA profile with different lipid sources. Different lipid sources also have marked effects on different sensory traits in the farmed Arctic charr.

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Reports

Genetics kit for char

Published:

01/02/2008

Authors:

Sigurlaug Skírnisdóttir, Alexandra M. Klonowski, Sigurbjörg Hauksdóttir, Kristinn Ólafsson, Helgi Thorarensen, Einar Svavarsson, Sigríður Hjörleifsdóttir

Supported by:

Tækniþróunarsjóður Rannsóknamiðstöð Íslands

Contact

Sigurlaug Skírnisdóttir

Project Manager

sigurlaug.skirnisdottir@matis.is

Genetics kit for char

The goal of the project was to create a powerful genetic kit for char with 15-20 genetic markers. Many genetic markers have been published for char and other salmonids, but the disadvantage is that no suitable reproduction gene set is known, which is a prerequisite for the efficient use of technology. It is important that the genetic markers show variability within the strain, are of a certain size but of different sizes, work well in a amplification reaction solution and are well readable after the sample has been run on a sequencer. The risk in the project was whether it would be possible to find a suitable genetic marker that could be combined into 2-3 reaction mixtures. 70 pairs of indicators were tested for 56 published genetic markers. The result of the project was that it was possible to combine 17 genetic markers into 3 reaction mixtures. A total of 140 fish were identified from the Hólar fish stock with these 17 genetic boundaries, but in addition, 12 wild fish were identified with them. The results showed that the genetic markers were used to differentiate between different groups of char. The processing of genetic analyzes clearly confirmed that Hólableikjan is mainly made up of two species. Some genetically modified wild charr yielded new isotopes not seen in farmed fish. Therefore, there are now genetic marketing kits that can be used in breeding work, in stock research on wild char and in traceability research. This will strengthen breeding work and is a powerful tool for research on char in the future.

The goal of the project was to develop genotyping protocols for Arctic charr containing multiplexes of 15-20 microsatellite markers. Many microsatellite markers have been published for salmonoid fishes, but no multiplexes are known which are of practical use when analyzing many samples at a time and therefore, to make the research profitable. The microsatellite markers must show variability among the fishes, they must be of certain sizes and of variable sizes, they must be amplifiable in multiplex PCR reactions and they must be easily readable from the machine. The risk of the project was to find published microsatellite markers which would fulfill these criteria and fit into 2-3 multiplex PCR reactions. Seventy primer pairs were tested for 56 published microsatellite markers. The results of the project were that 17 microsatellite markers which fit into 3 multiplex PCR reactions. A total of 140 fish from the brood stock of Arctic charr from the University at Holar was analyzed in the study as well as 12 samples from wild fish of different lakes and rivers. The results indicate that these markers can be used to analyze different stocks of Arctic charr. Furthermore, analyzes of the brood stock confirms that it mainly consists of two different stocks. New alleles were observed in the wild fish compared to the brood stock fish. A genotyping protocol to analyze Arctic charr for use in breeding industry, in wild fish research and in tractability analyzes, is now available. This will help in building up breeding programs and will be a helpful tool of the genetic research of Arctic charr.

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