A 60-day feeding experiment was conducted to evaluate the effects of dietary chromium (Cr) on carbohydrate utilization and growth performance of Labeo rohita fingerlings. Fishes were fed with four high carbohydrates (53%), isonitrogenous (crude protein 35%), and isocaloric (415 Kcal, 100 gm−1 ) experimental diets containing different levels of dietary chromium picolinate (Cr-Pic) viz.0, 400, 800, and 1200 μg kg−1 diet. Weight gain (WG%), specific growth rate (SGR), feed efficiency ratio (FER), and protein efficiency ratio (PER) was significantly increased at 800 μg kg−1 diet chromium supplementation (P < 0.05). CrPic supplementation (800 μg kg−1 ) also significantly (P < 0.05) enhanced the protein: DNA ratio in muscle, while DNA: RNA and DNA: tissue ratios were significantly (P < 0.05) decreased indicating higher growth. Significantly higher amylase, protease, and lipase activities were recorded in 800 μg Cr-Pic kg−1 diet-fed fishes (P < 0.05), while any of the experimental groups showing no significant (P > 0.05) change in hexokinase activity, indicating normal glycolysis in all. Furthermore, significant (P < 0.05) decrease in glucose-6-phosphatase activity in the 800 μg Cr-Pic kg−1 diet-fed group, showcasing evidence for protein-sparing action with Cr-Pic supplementation. Significantly (P < 0.05) higher serum insulin and liver glycogen in 800 μg Cr-Pic kg−1 diet-fed fishes denote an improvement in carbohydrate metabolism. However, significantly (P < 0.05) higher ATPase and SOD activities were also observed when chromium supplementation was more than 800 μg kg−1 diet, indicating stress at a higher level. The present study indicates that growth and carbohydrate utilization can significantly (P < 0.05) be improved by feeding the L. rohita fingerlings with Cr-Pic (800 μg kg−1 diet) supplemented diet in laboratory conditions.
Read More: http://eprints.cmfri.org.in/15491/
