THE EFFECT OF DIETARY-FAT IN MARKET RAINBOW-TROUT ON FISH WEIGHT-GAIN, CONVERSION COEFFICIENT AND CHEMICAL-COMPOSITION OF BODY

An experiment was conducted on 17,122 market rainbow trouts kept in co ncrete-made pools of 1m(3) water volume to determine the effect of 4% addition of three kinds of oils (fish, rapeseed and sunflower) to diet s of our own uniform formulation (average fat content of 11%) on feed efficiency and some other parameters. Two imported feeds with 13.35% a nd 18.49% fat contents for market rainbow trout were used parallelly w ith the diet of our own formulation. The effect of the kind of oil on feed efficiency was insignificant. The difference in feed efficiency b etween the imported feeds with 13.35% of fat and diets of our own form ulation was also insignificant. The highest (statistically significant ) feed efficiency was achieved by administration of imported feeds wit h 18.49% fat and 38.3% crude protein. The chemical composition of rain bow trout body samples was affected insignificantly by the use of five types of feeds. A trend toward the lowest fat content in fish bodies and the highest crude protein content was observed in a group receivin g the diet of our own formulation with an addition of 4% rapeseed oil.