Dietary replacement of artificial feed with bioflocs cultured from aquaculture waste water and its beneficial effect on the growth of fingerlings of Cirrhinus mrigala

摘要

Biofloc technology, the new blue revolution in aquaculture works with minimum or zero water exchange and recycling of nutrients. It converts the nitrogen present in aquaculture waste into microbial flocs which have great nutritional value and act as natural fish food. The bioflocs thus formed can partially or completely replace artificial feed in aquaculture. In the present investigation, the growth performance of Cirrhinus mrigala fingerlings was analysed by replacing commercial feed with bioflocs along with some physicochemical parameters viz. temperature, pH, DO, FCO2, ammonia, nitrite and nitrate. A 90-day experiment was conducted in tubs having 60 litre capacity, each stocked with 15 fingerlings. The experimental unit consisted of four sets which were provided with different diets having artificial feed @ 2% body weight (Control), 50% artificial feed and 50% bioflocs (Treatment I), 100% bioflocs cultured externally (Treatment II) and 100% in-situ bioflocs grown along with fishes in the same system (Treatment III). The growth of fingerlings was analysed in terms of mean weight gain, percent weight gain and specific growth rate. The results showed maximum growth of fingerlings in Treatment III and minimum in Control thereby revealing that artificial feed in the diet of C.mrigala can be replaced by bioflocs.