Tag: Lining

Reports

Increased sustainability in Aquaculture with focus on feed and sidestreams

Published:

25/06/2024

Authors:

Birgir Örn Smárason, Anna Berg Samúelsdóttir, Gunnar Þórðarson and Margrét Geirsdóttir

Supported by:

Nordic Council of Ministers - Working Group for Fisheries (AG-Fisk)

Contact

Birgir Örn Smárason

Research Group Leader

birgir@matis.is

The Nordic countries are major players in fish farming, including salmon (Salmo salar). Many demanding environmental issues are related to this production and they are found in every step of the process. The main focus of this report has been on new feed ingredients and improved utilization of by-products. Both of these issues concern a large amount and it is of great importance for the business world as well as the sustainability and environmental impact of this important profession that they are handled in a better and more efficient way than the current methods. Future food security for our planet's population, in a sustainable manner in the long term, requires a revolution in the way we produce our food. There is an urgent need to maximize sustainable feed production.
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The Nordic countries are big players in salmon aquaculture (Salmo salar). Many challenging environmental issues are related to this production, and they are to be found in every step of the process. The main focus in this report has been put on novel and alternative feed ingredients and sidestreams utilization. Both those issues involve vast volumes and it's of high importance for the economy as well as the sustainability and environmental impact of this important profession that they are tackled in a better and more efficient manner than current approaches. Future food security for our global population that does not compromise the long-term sustainability of our ecosystems requires a revolution in the way we produce our food and there is an urgent need to nutritionally optimize a sustainably produced feed ingredient for inclusion in aquafeeds. 

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Reports

Use of canola oil in winter feed for salmon in the sea / Use of canola oil in winterdiets for Atlantic salmon

Published:

01/02/2014

Authors:

Jón Árnason, Jón Örn Pálsson, Gunnar Örn Kristjánsson, Ólafur Ingi Sigurgeirsson, Arnþór Gústafsson

Supported by:

AVS fund reference no. R 089‐12

Use of canola oil in winter feed for salmon in the sea / Use of canola oil in winterdiets for Atlantic salmon

An experiment was performed with different amounts of rapeseed oil (0, 50 and 80%) in winter feed for 570 grams of salmon raised in the sea with 28.2 ‰ salt (26 - 34 ‰) at an average temperature of 4.5˚C (3.8 - 5 , 6˚C). The fish doubled in weight during the 152-day trial period. TGC3 was an average of 2.9. The fat content of the feed had very little effect on the growth, feed intake, feed utilization and volume content of fish fillets. The composition of the feed fat did not have much effect on the color of the fillets, although fish that were fed only fish oil gave significantly (p = 0.017) lighter fillets than fish that were fed with rapeseed oil. The type of fat in the feed, however, had a significant effect on the fatty acid composition of the fat in both the feed and the fat in the fillets, especially the EPA, DHA content and the ratio of n-6 and n-3 fatty acids. However, the results show that the effect in the fillet fat is much smaller than in the feed fat, especially with the fatty acid DHA. It seems that DHA converts feed fat into fillet fat rather than using it as an energy source.

An experiment with different inclusion of Canola oil (0, 50 and 80%) in diets for 570 grams Atlantic salmon that was reared in sea water with average salinity of 28.2 ‰ (26 - 34 ‰) at average temperature of 4.5˚ C (3.8 - 5.6˚C). The fish doubled its weight during the 152 days trial period. TGC3 was on average 2.9. The fat type had had only minor effects on growth, feed intake, feed conversion and nutrient content in filet. The fat type in the diet did not have much effect on the filet color even though the fish that got feed with fish oil was significantly (p = 0.017) lighter in filet color than fish that got diets with Canola oil. Composition of the diets had market effect on the fatty acid composition of both dietary fat and filet fat in particular the content of EPA and DHA and the n ‐ 6 to n ‐ 3 ratio. However the results show lower effect in the filet fat than in the dietary fat, particularly regarding the content of DHA indicating that the fish is directing that fatty acid towards the storage lipid in the filet rather than using it as energy source.

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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

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

Fat tolerance of cod

Published:

01/07/2008

Authors:

Jón Árnason, Rannveig Björnsdóttir, Helgi Thorarensen, Ingólfur Arnarson

Fat tolerance of cod

The purpose of this study was to investigate the effect of fat content in feed on the growth and cleaning of cod of different sizes. Knowledge of the nutritional needs of fish is a necessary prerequisite for the preparation of feed for them. Two-size cod (120 g and 600 g) were fed (in triplicate) for 12 weeks on feed containing 10.0%, 13.5%, 21.2%, 24.5% and 27.7% fats in dry matter. Different fat content did not affect growth (SGR), body mass index (CF), fillet utilization, liver fat content or fillet fat content. In the smaller fish, the feed index (FCR) decreased with increased fat in the feed. The feed fat did not affect the fat content of offal without liver in the smaller fish (120g) but in 600 g fish the fat in the intestines increased with increased fat content of the feed. The fat content did not affect the proportion of gutted weight of the total weight in the 600 g fish, but in the smaller fish the proportion decreased with increased fat in the feed. Liver ratio (HSI) in 600g fish was not dependent on the fat content of the feed, but there was a positive correlation between feed fat and HSI in the 120 g fish. This means that the fat tolerance of cod in terms of liver ratio depends on the size of the fish.

Detailed knowledge of the nutritional requirements of fish is essential for feed formulation. The aim of this research was to investigate the effects of different lipid content in diets for Atlantic cod of different size. Cod of two size groups (initial weight 120 grams and 600 grams) were fed, in triplicate, for 12 weeks diets containing 10.0%, 13.5%, 21.2%, 24.5% and 27.7% lipid in dry matter. Different lipid content in the diet did not affect growth (SGR), condition factor (CF), fillet yield, lipid content in liver or lipid content in fillet. In the smaller fish, FCR was reduced with increased diet lipid. The lipid content in the diet did not affect the lipid content of intestines in the 120 grams fish but in the 600 grams fish there was a positive correlation between lipid content in diet and intestines. Dietary lipid did not affect gutted weight (calculated as the percentage of round weight) in the 600 grams fish but in the 120 grams fish, the percent gutted weight decreased with lipid content of the diet. The Heposomatic index (HSI) in the 600 gram fish was not affected by the lipid content of the diet but dietary lipid content significantly affected the HSI in the smaller fish. This indicates that the lipid tolerance of Atlantic cod, with respect to the effect on HSI, is size dependent.

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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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