ACORN MEAL AS A NUTRIENT IN RAINBOW TROUT (ONCORHYNCHUS MYKISS) DIET

A complete random design involving four diets was conducted to determine the effects of Different levels of dietary acorn meal on [mal weigh, food consumption and food conversion ratio of rainbow trout. Juvenile Rainbow Trouts with an average weight of 74 grams were reared after antiseptic processes in Boldaji station of Chaharmahal and Bakhtiari province for 135days. We formulated diet treatments 1-4 containing 0, 2, 4 and 6 percent of acorn meal respectively. In doing so, we considered nutritive requirements of rainbow trout based on NRC using UFFDA dietary software. We also used local material in providing the diet. The food was given three times a day the amount of which was based on fish biomass in each pound. Once every two weeks, after anaesthetizing 50 percent of fishes in each pound, we measured fish weight and length. The results showed that treatment 4 containing 6% of acorn led to the highest fish weight increase while being significantly different with other treatments. In terms of fish length, the longest length was observed in treatment 4, which had significant difference with treatment 1. Food consumption differences was not significant between treatments, but was higher in treatment 4. However, food conversion ratio was significantly affected by treatments, the highest of which was in treatment 4 significantly different with that of treatment 1. The results showed that acorn meal can be used as a nutrient in rainbow trout diet, improving fish weight and length gain while having no physiological effects on the fish.