A feeding trial was conducted to evaluate the effects of
chromium picolinate (Cr-Pic) on growth performance, body composition, and biochemical parameters in Nile tilapia Oreochromis niloticus. Five experimental diets were formulated with
high-protein diet (HP),
low-protein diet (LP), and LP + 0.6, 1.2, or 1.8 mg kg-1 Cr, respectively. Each diet was randomly assigned to four replicate groups of 30 fish per aquarium in a water-circulated rearing system for 60 days. Dietary 1.2 or 1.8 mg kg-1 Cr inclusion significantly affects the final
body weight,
weight gain rate, specific growth rate, feed efficiency rate, and
protein efficiency ratio of tilapia compare to the LP diet. The Cr inclusion significantly decreased the content of blood
urea nitrogen and the
blood glucose level generally with increasing Cr inclusion levels. The Cr content of gill tissue was higher than that of back muscle in all treatments, and the addition of 1.2 or 1.8 mg kg-1 Cr significantly enhanced the Cr contents of back muscle. The cold stress test results showed that adding Cr significantly enhanced the serum T3 concentration and reduced the activity of serum
creatine kinase and the serum
cortisol level. These results indicated that the supplementation of
chromium picolinate can improve the growth performance and reshape the
serum protein and carbohydrate metabolism profile and has the potentiality to alleviate the detrimental effects of cold stress in Nile tilapia. The
low-protein diet with 1.8 mg kg-1 Cr obtained the same growth performance as the
high-protein diet.