author(s)
Priyanka Arya, Deepshikha Chandra, Akansha Khati and RS Chauhan

abstract
The aim of present work was to investigate the effect of varying levels of Probiotics on specific growth rate (SGR), feed conversion ratio (FCR) and feed conversion efficiency (FCE) of Catla catla fingerlings. The fingerlings weighing 10.69±1.09 g were distributed randomly into three treatment groups T1, T2 and T3. Three isonitrogenous diets were prepared by mixing rice polish, deoiled mustard oil cake, maize flour and vitamin mineral mixture. The biomedicine was incorporated into diet D₂ @ 5% and D₃ @ 10%. In control diet D_1, there was no supplementation. T1 group fishes were fed with D₁ diet, T2 with D₂ and T3 with D₃ @ 5% body weight per day for a period of 60 days. Treatment T3 fishes showed significantly better growth performance than those of T2 and control groups T1. Fingerlings fed with diet D3 achieved higher SGR (1.35%±0.02), FCR (1.06±0.02) and FCE (0.93±0.01) as compared to other treatments. The result suggests that the inclusion of the biomedicine probiotic @ 10% in diet of Catla catla is useful to get the best fish performance with no harmful effects on the environment.