University of Guilan Aquatic Physiology and Biotechnology 2345-3966 4 4 2017 02 19 Effect of replacing dietary fish oil with vegetable oils on serum hepatic enzymes and liver histology of rainbow trout (Oncorhynchus mykiss) Effect of replacing dietary fish oil with vegetable oils on serum hepatic enzymes and liver histology of rainbow trout (Oncorhynchus mykiss) 69 88 2196 FA Iman Zare Haghighi Afshin Ghelichi Sara Jorjani Journal Article 2016 05 06 <span>This study was conducted to evaluate the effect of replacement of fish oil (FO) by vegetable oils on liver histology and serum hepatic enzymes of rainbow trout, <em>Oncorhynchus mykiss</em>. Four experimental diets were formulated with complete replacement of FO (treatment 1) with soybean oil (treatment 2), sunflower oil (treatment 3), and canola oil (treatment 4). Twenty-five fish (65.12±1.13g mean weight) were allotted for each treatment tanks in duplicates groups at random and were fed for 50 days. There were no significant differences in the final weight of fish in any treatment. The results showed that serum AST, ALT</span><span>and LDH levels were higher in fish fed the FO diet than the other fish. Hepatic lesions in liver tissue of all fish were characterized as hydropic degeneration, hepatocytes hypertrophy, necrosis, congestion and bleeding. Besides, liver tissues of treatment 1 (control) showed higher degree of liver lesions. These results indicate that oxidation of fish oil can cause hepatic lesions and increasing of serum hepatic enzymes in rainbow trout. In conclusion, mix of vegetable oils and fish oil can replace the sole use of fish oil in rainbow trout diet. Also, when using fish oil in the diet should be a lot of attention to its quality. </span> <span>This study was conducted to evaluate the effect of replacement of fish oil (FO) by vegetable oils on liver histology and serum hepatic enzymes of rainbow trout, <em>Oncorhynchus mykiss</em>. Four experimental diets were formulated with complete replacement of FO (treatment 1) with soybean oil (treatment 2), sunflower oil (treatment 3), and canola oil (treatment 4). Twenty-five fish (65.12±1.13g mean weight) were allotted for each treatment tanks in duplicates groups at random and were fed for 50 days. There were no significant differences in the final weight of fish in any treatment. The results showed that serum AST, ALT</span><span>and LDH levels were higher in fish fed the FO diet than the other fish. Hepatic lesions in liver tissue of all fish were characterized as hydropic degeneration, hepatocytes hypertrophy, necrosis, congestion and bleeding. Besides, liver tissues of treatment 1 (control) showed higher degree of liver lesions. These results indicate that oxidation of fish oil can cause hepatic lesions and increasing of serum hepatic enzymes in rainbow trout. In conclusion, mix of vegetable oils and fish oil can replace the sole use of fish oil in rainbow trout diet. Also, when using fish oil in the diet should be a lot of attention to its quality. </span> https://japb.guilan.ac.ir/article_2196_e3406716c0a7e6845edd82dca3ab8311.pdf