Evaluation of the physiological effects of Trichoderma sp. on growth factors, hematology and approximate analysis of carcass composition in rainbow trout (Oncorhynchus mykiss)

Over many years, with the increase in population, the increasing human demand for food consumption and the importance of maintaining environmental security, researchers have paid attention to the use of microorganisms to increase the amount of product per unit area more than in the past. Some species of Trichoderma fungus are known as growth promoters in plants. The sensitivity of different species of fish to toxic substances is different, so toxicology tests are done on different fish. In this experiment, 120 pieces of rainbow trout (Oncorhynchus mykiss) with 3 types of Trichoderma fungi (Trichoderma afroharzianum, Trichoderma ghanens, Trichoderma lixii), treatment 1 (TC-1), treatment 2 (TC-3), treatment 3 (TC-4) and control treatment (CL) were fed completely randomly. Finally, growth factors (daily growth rate, weight gain percentage, specific growth factor, food conversion factor), approximate carcass analysis (protein, fat, ash, and moisture), and hematology (hemoglobin, hematocrit, white and red blood cells, neutrophils, Monocyte, lymphocyte, mean hemoglobin red blood cells (MCHC), size red blood cells (MCV), mean hemoglobin red blood cells (MCH)) were evaluated. The investigation growth factors showed that the treatment (TC-3) had significant difference with other treatments and the control group. Also, the evaluation of blood parameters in this research showed that Trichoderma significantly reduces the level of these factors in rainbow trout. The analysis of the rainbow trout carcasses in the treatments fed by different strains of Trichoderma showed that the amount of protein, fat and moisture in the control groups and the treatments were not significantly different; but the lowest amount of cholesterol and triglyceride was observed in the control. Considering the changes in the hematological factors of fish treated with Trichodema, the measurement of these factors can be used as biological index, a tool for monitoring and evaluating the health of aquatic ecosystems. Since it is necessary to use chemical pesticides and their toxicity even in very small concentrations on fish, it is important to investigate the adverse effects of chemical pesticides on aquatic health from the perspective of fisheries and environment.