Effect of different rates of dietary pomace oil impact ongrowth and body composition of rainbow trout (Oncorhynchus mykiss W, 1792)

In this study, effects of different levels of dietary pomace oil on growth, nutrient composition and nutrient digestibility of rainbow trout (Oncorhynchus mykiss) were investigated.Four experimental diets with equal lipid content containing 15% fish oil (R1), 5% (R2), 10% (R3), 15% pomace oil were formulated for rainbow trout with a mean of 94.04±0.58 g and fed for 60 days.At the end of the experiment, live weight gain, specific growth rate, feed intake, feed conversion rate, protein effiency ratio and also nitrogen and oil intake, accumulation, loading and retention were unaffected by in the diets pomace oil ratio (p>0.05). Pomace oil rate in the diet on the crude protein, crude fat, crude ash and total energy values in fish flesh has no effect, but the moisture content of fish flesh of pomace oil rate in the diet was affected significantly with the release of 10%, respectively (p <0.05). The lipid contents of liver was significantly affected (p<0.05) from pomace oil rate in diet. The lowest lipid contents of liver (6.10±0.09) were obtained from group R1 that contained 15% fish oil and the highest lipid contents of liver (7.78±0.02) were obtained from group R4 that contained 15% pomace oil. While the pomace oil diet rate was not effected on viserosomatic index, carcass yield and condition factor, hepotosomatic index values were significantly affected. There were significantly (p<0.05) differences between all groups that contains fish oil and pomace oil.At the end of the experiment digestion rate not affected from pomace oil rate but total digestion and protein digestion rate in feed was found significantly (p <0.05) important with the pomace oil rate increased to 15%.Obtained, fish oil in the rainbow trout feed could be used instead of the whole were identified. When the growth, body composition and digestion rates were taken into consideration, pomace oil in rainbow trout feed could be used instead of the whole fish oil have been identified.Key words: Rainbow trout (Oncorhynchus mykiss), pomace oil, growth performance, nutrient composition