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oPtimiZinG GroWtH AnD QUALitY of fArmeD coD At 67◦n
Christel Solberg
Department of Fisheries and Natural Science
Bodø University College
N-8049 Bodø, Norway
www.hibo.no
Major roads to ensure optimal production conditions for cod is either to change the feeding conditions or by changing the feed
composition.
Experiments done in North Norway showed that decreasing the number of given meals per week from five times to 2 times
a week, resulted in the same growth and the same quality of the cod with a considerable reduction in the FCR from 1.47 to
1.35.
In another experiment it was used feed from three different companies in a full scale trial, to elucidate if the different feed had
any effect on the growth or quality of the fish.
Cod juveniles with an average size of 100g produced in Vestlandet, were transported to Bodø in the end of October 2004. It was
used about 35.000 fish in each 60 m netpen. Samplings of fish were performed in January 2005, June, August, January 2006,
July and September.
The proximate composition of the feed was approximately similar in the different feed, 55-52 % protein and 15-20% fat.
However, in September 2006 significant differences in the gutted weight were found. There were not found any differences in
conditionfactor, liverindex or muscle watercontent. The fatty acid composition in the liver was different for the different feed,
indicating different sources of the oil in the feed. It was observed green spots on the liver, especially from cod fed with one of
the feeds, making the cod liver unsuitable for the commercial market. The reason for this discoloration is for the moment not
known.