The effect of a diet containing spoiled fish meal and the protective effects of vitamin E and C supplements on growth, hematological and biochemical indices of rainbow trout juveniles (Oncorhynchus mykiss)

The present study was carried out with the aim of investigating the effect of a dietary spoiled fish meal along with the protective effects of vitamins E and C on the growth, hematological and biochemical indices of rainbow trout fingerlings. For this purpose, 240 rainbow trout fingerlings with an average weight of 12.75±0.25g were fed on 4 treatments diets including: 1: a diet containing fresh fish meal; treatment 2: a diet with spoiled fish meal; treatment 3: a diet with spoiled fish meal and low level of vitamin supplements (100mg/kg vitamin E, 200mg/kg vitamin C) and treatment 4: a diet containing spoiled fish meal and high levels of vitamin supplements (200mg/kg vitamin E, 400mg/kg vitamin C) for 60 days. At the end of the test period, the indices of final weight, specific growth rate, body weight gain, and food conversion ratio were calculated. Also, hematological parameters, cholesterol, triglyceride, HDL, and LDL were evaluated. Based on the obtained results, the final weight, specific growth rate, and body weight gain decreased in treatments 2, 3, and 4, while the food conversion ratio increased (P≥0.05). WBC and Hb increased in treatments 3 and 4 (P≥0.05). RBC and Htc% augmented in treatment 3 (P≥0.05). Triglyceride diminished in treatments 3 and 4 (P≥0.05), but cholesterol and LDL increased in treatments 2 and 3 and decreased in treatments 2 (P≥0.05). HDL has grown in treatments 3 and 4 (P≥0.05). It can be concluded that spoiled fish meal harms growth, hematological, and biochemical indices, and vitamin supplements are impacts on reducing these effects in hematological and biochemical indices.