Effect of different levels of dietary Bakers Yeast (Saccharomyces cerevisiae) On Growth performance and feed utilization in Rainbow Trout (Oncorhynchus mykiss) alevin

The aim of present study was to evaluate the effect of different levels of yeast probiotic on growth، feed utilization and survival of rainbow trout (Oncorhynchus mykiss) alevins. This experiment conducted in a completely randomized design with four treatments which had triplicates. Four levels of yeast (0، 3%، 6% and 9% of ration) were added to the basic diet. Fish alevins were fed by experimental diets 4 times a day at 5 to 6% of body weight for 30 days. Rainbow trout larvae (average individual weight، 176 mg) were randomly distributed with density of 4 fish/l into twelve 10 liter fiberglass tanks. The results indicated that the Saccharomyces cerevisiae could not influence growth and feeding parameters in rainbow trout alevin. The final body weight and specific growth rate (SGR) in experimental treatments had not significant difference in comparison with control treatment (P≥0. 05). The bakers yeast had not significant positive effects on food conversion efficiency (FCE)، thermal growth coefficient (TGC) and feed conversion ratio (FCR). This study showed that S. cerevisiae had not high efficiency in feeding parameters and growth performance of rainbow trout alevin.