Chromium Supplementation in Diet Enhances Growth and Feed Utilization of Striped Catfish (Pangasianodon hypophthalmus).

Chromium (Cr) is a trace element and plays a significant role in fish nutrition and physiology. An experiment was designed to know the effects of Cr addition in the diets to growth and feed utilization in striped catfish (Pangasianodon hypophthalmus). Four diets with Cr (0, 2, 4, and 8 mg kg-1) were fed to striped catfish in aquaria with triplicate groups for 60 days. Survival, growth parameters (weight gain, WG; %WG; specific growth rate, SGR), and feed utilization (feed intake, FI; feed efficiency, FE; protein efficiency ratio, PER; feed conversion ratio, FCR) were calculated at the end of the feeding trial. Several hemato-biochemical parameters, such as hemoglobin (Hb), red blood cell (RBC), white blood cell (WBC) and glucose level, and frequency of micronucleus (MN) formation in erythrocytes, were analyzed. The growth parameters (WG, %WG, and SGR) and feed utilization (FE and PER) increased significantly in the fish fed with 2 and 4 mg kg-1 Cr supplemented diets. On the other hand, the growth parameters suppressed in the fish fed with 8 mg kg-1 Cr-based diet. The polynomial regression analysis based on WG showed that 2.82 mg kg-1 Cr supplementation in the diet is optimum for the tested fish species. The values of Hb (g/dL), RBC (×106/mm3) and blood glucose (mg/dL) significantly decreased in the fish fed with the highest (8 mg kg-1) Cr-based feed. Conversely, MN frequency was significantly increased in the fish fed with 8 mg kg-1 Cr-based diet. Overall, 2.82 mg Cr kg-1 can be added to the diets of striped catfish for its better growth with maximum utilization of feed.