Effect of Dietary Replacement of Fish Meal with Whey Protein on Growth, Survival and Some Biochemical Parameters of Rainbow Trout (Oncorhynchus mykiss) Fingerlings

Whey protein is regarded as a valuable low-cost protein source which may be added in the diet of fish to improve growth and survival. In the present study to check its efficacy a sixty (60) day feeding trial was conducted to evaluate effect of dietary replacement of fish meal with whey protein on growth, survival and some biochemical parameters of rainbow trout (Oncorhynchus mykiss) fingerlings. After an acclimatization period of ten (10) days, a total of one hundred and fifty fingerlings (150) of average weight 20.0 ±1.0 gm were distributed in fifteen aquariums of 90 litre capacity by following a completely randomized design. Proper aeration was provided to each tank. Five iso-nitrogenous (45% crude protein) diets were prepared to replace 0%, 10%, 20%, 30% and 40% of fish meal with whey protein (WP) and in accordance the treatment groups were designated as Control (T0), T1, T2, T3 and T4 respectively. Feeding was done twice a day @5% of body weight. Water quality parameters were maintained at optimum level. Sampling was done initially and after every 15 days. The results indicated that the growth performance in terms of total weight gain (WG), feed conversion efficiency, protein efficiency ratio, specific growth rate (SGR) and feed conversion ratio (FCR) depicted significant difference (p< 0.05) between T0 and experimental group T3. Overall there was a significant difference (p< 0.05) between T0 and other experimental groups. The present study suggested that whey protein could be used to replace 30% of fish meal in the diets of O. mykiss without any adverse effects on growth performance, survival, feed utilization biochemical parameters and whole-body composition.