Usage of cotton seed meal with variety amount of Gossypol in rainbow trout (Onchorhyncus mykiss) diet

Cottonculture is common in many of point in IRAN specially Khorasan province. This study is doing for Usage of cotton seed meal with variety amount of Gossypol in rainbow trout (Onchorhyncus mykiss) diet.  In this examination the effect of various amount of Gossypol (common cotton seed, cotton seed with low Gossypol and  cotton seed without Gossypol in Rainbow trout growth in (GFT²) stage was done. At the beginning of the experiment, the fish’s weights were 140 gr. In the training ponds with the 2/240× 1/10 dimensions and 0/75 meter depth, 240 numbers of Rainbow trout were kept. Each treatment was consist of 20 number of Rainbow trout fish. The required water for culturing was provided from a spring in Khojir Research station which was close to the farm with 14 mean temperatures. Four experimental diets common cotton seed, cotton seed with low Gossypol and cotton seed without Gossypol for feeding during a six weeks cultural period. The diets that were consist of diverse levels of common cotton seed had significant differences (α=0.5%) on weight increasing, total length increasing, standard length increasing and conversion factor. In comparing between different treatments, the diet which had common cotton seed had significant differences in the statically sight in weight, conversion factor, FER, total and standard length regarding the other diets and also had the worst condition.