Effects of organic and inorganic chromium supplementation on the serum insuline, glucose and growth in rainbow trout (Oncorhynchus mykiss)

In this study, effects of organic (CrPic) and inorganic (CrCl3) forms of chromium on serum insulin, glucose and growth in rainbow trout were investigated. A total of 450 fishes, average initial body weight 50 g were used, tanks supplied with spring water and experiment continued for 120 days. The study was conducted at Sürgü Vocational School Research Unit of İnonü University. A basal diet was prepared and picolinate group (CrPic) supplemented with chromium picolinate, chloride group supplemented with chromium chloride (CrCl3). Supplemented elemental chromium level to the picolinate and chloride groups was 400 µg/kg and each diet fed to triplicate tanks.Fish feed with the CrPic and CrCl3 diets had significantly greater weight gain, relative growth rate and final body weight than control group (P<0.001) but not significant betwen picolinate and chloride groups. Feed conversion rate was not significantly different between picolinate and chloride group but control group had the greatest feed conversion rate than chromium supplemented groups (P<0.05). Blood glucose concentration was not significantly different between control and chloride groups but picolinate supplementation decreased glucose concentration significantly (P<0.001). Serum insuline concentrations between all groups were not significantly different.These results suggests that, supplementation of two chromium forms (CrPic, CrCl3?6H2O) at 400 µg/kg rate to rainbow trout practical diets improved growth and feed conversion rate.Key Words; Rainbow Trout, Chromium Chloride, Chromium Picolinate, Insuline, Glucose, Growth