Tag: Arctic charr

Reports

Minimizing the feed cost of Arctic charr

Published:

01/05/2014

Authors:

Jónína Þ. Jóhannsdóttir, Jón Árnason, Heiðdís Smáradóttir, Aðalheiður Ólafsdóttir, Rannveig Björnsdóttir

Supported by:

AVS reference no. R 09‐12

Minimizing the feed cost of Arctic charr

The results of previous studies have shown that it is possible to breed char on a protein-less feed than is traditionally used, thereby significantly reducing production costs in charr farming. Previous research has been carried out in experimental facilities and the aim of this project was to repeat feed experiments in real conditions during the production of char. Arctic charr were reared on two different compound feed types that contained different amounts of protein, which also came from different sources, with 50% of the fishmeal protein in the reference feed and 45% in the experimental feed. The effect of feed type on fish growth, chemical composition and quality factors was assessed. The results show that the different feeds tested did not affect the growth or quality of the products, and the results indicate that it is possible to reduce the proportion of protein in the feed and replace fishmeal with cheaper protein-rich plant raw materials. The results also show that it is possible to reduce the protein content compared to the feed currently on the market for char and thus reduce the production cost of char significantly. 

Previous results have suggested that Arctic charr can be reared on feed with lower protein content than is commonly used, without compromising growth rate and quality, and thus lowering production cost. Previous experiments have only been carried out using experimental conditions and but this project aimed aims at confirming previous results in large scale experiments carried out using at actual production conditions. Arctic charr was fed for eleven months on two feed formulations containing different total protein content and proteins of different origin, The test feed contained different proportions of fish meal with 45% of the protein originating from fish meal in the test diet as compared to 50% in the control feed. The effects of the diets on growth and product quality were nutritional factors was evaluated. The results indicate that the test diet feed tested neither did not affect growth nor and product quality of the product. Also, tThe results therefore suggest that it is possible to reduce the proportion the ratio of proteins and the fish meal in the diets for Arctic charr can be reduced and partially and substituted fish meal for by raw material of plant origin. This substitution of fish meal with less expensive raw material could reduce the cost of Arctic charr production considerably.

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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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