The effect of different levels of Mix oil on growth performance and survival rate of Oncorhynchus mykiss in challenging with Yersinia ruckeri

This study was conducted to evaluate the effects of different levels of Mix oilon growth performance and survival rate of Oncorhynchus mykiss inchallenging with Yersinia ruckeri. For this purpose, four groups of fish with mean initial weight of 31.1±0.1 g were raised for 8 weeks in cement tanks, including 80 fish in each tank and feeding with different levels of Mix oil(with concentrations of 0, 50 ppm, 200 ppm and 400 ppm, 3 replicates for each treatment). At the end of the trial, growth performance, and survival rate of fish inchallenging with Y. ruckeri were determined in different groups. Results showed that O. mykiss fed on diet supplemented with 400 ppm of Mix oil had significantly higher growth factors (body weight increase, specific growth rate, protein efficiency ratio, average daily growth) and survival rate compared to other treatments (p < 0.05). Based on the results, using of Mix oil, especially at the level of 400 ppm can improve the growth performance and survival rate of O. mykiss inchallenging with Y. ruckeri.