نوع مقاله : مقاله پژوهشی
1 گروه شیلات، دانشکده علوم و فنون دریایی و جوی، دانشگاه هرمزگان، هرمزگان
2 گروه شیلات، دانشکده منابع طبیعی، دانشگاه گیلان، صومعه سرا، گیلان
عنوان مقاله [English]
Effects of vitamins C and E - supplemented diet on hematological indices of rainbow trout Oncorhynchus mykiss juveniles at two different densities were investigated in a 6-week trial. Rainbow trout juveniles (initial body weight of 9.6 ± 0. 69 g) at two stocking densities of 50 and 100 fish per 50 liters were fed three diets containing the same level of protein and fat, but with different levels of the vitamins. Experimental diets included diet 1 without vitamins, diet 2 supplemented with 1500 mg/kg vitamin C and diet 3 with 600 mg/kg vitamin E. A total number of 1350 rainbow trout juveniles were devided in six treatments each with three replicates as T50(0) (density = 50, fed diet 1), T100(0) (density = 100, fed diet 1), T50(C) (density = 50, diet 2), T100(C) (density = 100, diet 2), T50(E) (density = 100, diet 3) and T100(E) (density = 100 diet 3). After a 6-week feeding, hemoglobin level, the number of red blood cells and sodium level were significantly higher in T100 treatments (P<0.05). Plasma glucose and cortisol were also significantly higher in T100 treatments (the highest in T100(0)) than in T50 treatments (the highest in T50(0)) (P<0.05). T50 treatments had higher levels of blood albumin and total protein (P<0.05). There were no significant differences in number of white blood cells and potassium level between treatments (P>0.05). According to the results, supplementing the diet of rainbow trout with vitamins C and E enhances fish resistance to the stressful environment caused by stocking density.