The effect of hydrolyzed protein, vitamin E and oxidized oil on growth performance, hematology and fillet quality of rainbow trout (Oncorhynchus mykiss)

Najafi, Esfandyar; Hosseini, Seyed Vali; Farahmand, Hamid; Mojazi Amiri, Bagher; Soltani, Mahdi

doi:10.22059/jfisheries.2021.316962.1221

The effect of hydrolyzed protein, vitamin E and oxidized oil on growth performance, hematology and fillet quality of rainbow trout (Oncorhynchus mykiss)

Document Type : Research Paper

Authors

Esfandyar Najafi ¹

Seyed Vali Hosseini ²

Hamid Farahmand ³

Bagher Mojazi Amiri ³

Mahdi Soltani ⁴

¹ Ph.D student,Department of Fisheries Science, Faculty of Natural Resources, University of Tehran, Karaj, Iran.

² Department of Fisheries and Environmental Sciences Faculty of Natural Resources College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.

³ professor, Department of Fisheries Science, Faculty of Natural Resources, University of Tehran, Karaj, Iran.

⁴ professor, Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

10.22059/jfisheries.2021.316962.1221

Abstract

Rainbow trout fish fed one of the diets containing fresh kilka oil with 50 mg kg-1 of vitamin E 1)without (control A, FO50) or 2)with hydrolyzed protein (4% replacement for fishmeal) (treatment B, FO50HP), 50 mg kg-1 vitamin E with oxidized oil 3)without (treatment C, OO50) or 4)with hydrolyzed protein (treatment D, OO50Hp), 250 mg kg-1 vitamin E with oxidized oil 5)without (treatment E, OO250) or 6)with hydrolyzed protein (treatment F, OO250HP) in a completely randomized design (six treatments and three replications) for eight weeks. The lowest FCR was in treatment B and the highest was in treatment E (P< 0.05). The amount of other growth indices were higher (P< 0.05) in treatments A and B than other treatments. The highest and lowest concentrations of alanin amino transferase (ALT) occurred respectively in treatment C and treatments A and B (P< 0.05), the highest and lowest concentrations of aspartate amino transferase (AST) occurred in treatments C and D and treatment B (P< 0.05), respectively. The highest neutrophil (Nut) and the lowest lymphosit (Lym) percentages were in treatment E while the vise versa were observed in treatment C (P< 0.05). The phagocytosis amount was highest in treatments C and D while it was the lowest in treatment A (P< 0.05). The fillet 14: 1n-9 concentration was the highest in treatment F while it was the lowest in treatment B (P< 0.05). The fillet 18: 0 content was the highest in treatment A and the lowest in treatment D (P< 0.05). Treatment D showed the highest fillet 20: 4n- 6 content while treatment F had the lowest content (P< 0.05). Accordingly, vitamin E (50 mg kg-1 diet) with hydrolyzed protein (as a substitute for fish meal by 4%) would be able to prohibit the damages resulting from oxidative stress in growing rainbow trout.

Keywords

Rainbow trout

vitamin E

hydrolyzed protein

oxidized oil

oxidative stress