~ 59 ~ Journal of Entomology and Zoology Studies 2020; SP-8(4): 59-65 E-ISSN: 2320-7078 P-ISSN: 2349-6800 www.entomoljournal.com JEZS 2020; SP-8(4): 59-65 Kuldeep Singh Rana College of Fisheries, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India Avdhesh Kumar College of Fisheries, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India Corresponding Author: Avdhesh Kumar College of Fisheries, G.B. Pant University of Agriculture and Technology, Pantnagar Uttar Pradesh, India International Web-Conference On New Trends in Agriculture, Environmental & Biological Sciences for Inclusive Development (21-22 June, 2020) Impact of Withania somnifera (Ashwagandha) as an exogenous growth promoter in the diet of fingerlings of Labeo rohita in Tarai region Kuldeep Singh Rana and Avdhesh Kumar Abstract The present investigation was conducted to assess the effect of different doses of Ashwagandha supplemented feed in Labeo rohita on growth rate, feed conversion ratio, condition factor, protein efficiency ratio and gross protein retention. Experiment comprised of 3 treatments viz. Diet containing Ashwagandha @1%, 3% and control diet with no supplementation. Results revealed that diet containing 3% Ashwagandha resulted in better FCR, growth rate, condition factor and higher protein retention. The results obtained with this diet were superior to other treatments and significantly different (P<0.05), however the diet containing 1% Ashwagandha also yielded better results than the control diet but not as good as diet containing 3% Ashwagandha. All the physicochemical parameters were within the optimum range as desired for fish culture practices. Any kind of adverse effects due to Ashwagandha on the water quality parameters, behavioral and feeding response of fish were not encountered during the period of investigation. Keywords: Ashwagandha, Labeo rohita, Growth rate Introduction The present status of aquaculture industry possesses challenges and opportunities for improvement of production to meet the growing demands in coming years. This demand may be fulfilled by increasing the quality of aqua feeds through improving nutrient content as well as digestibility of low quality feed by the use of efficient feed additives. Withania somnifera, is commonly known as Ashwagandha, Indian ginseng, Winter cherry, Ajagandha, Kanaje (Hindi), Amukkara (Tamil) and Samm Al Ferakh (Urdu), it belongs to family Solanaceae. The main constituents of ashwagandha are alkaloids and steroidal lactones. Among the various alkaloids withanine is the main constituent. The other alkaloids are somniferine, somnine, somniferinine, withananine, pseudo withanine, tropine, pseudo tropine, cuscohygrine, anferine and anhydrine. Two acyl steryl glucoside viz. sitoindoside VII and sitoindoside VIII have been isolated from root (Kumar A. 2000) [10] . The leaves contain steroidal lactone, which is commonly called withanolide which has C28 steroidal nucleus with C9 side chain, having six membered lactone ring. (Mowrey, D.1986). The experimental fish, Labeo rohita (rohu) is an indigenous fish species of family Cyprinidae and it is being used as an integral member of four or six species composite culture in the country. Supplementary feed forms the major input constituting over 50 percent of the recurring expenditure in grow out. Though many of plant origin ingredients have demerits on account of presence of antinutritional factors which have an adverse impact on the digestion and nutrient utilisation of feed however, certain enzymes provide an additional powerful tool that can inactivate antinutritional factors and enhance the nutritive value of plant based protein in feeds. These provide a natural way to transform complex feed components into digestible nutrients (Alikunhi, K. H. 1957) [1] . Judicious feed management therefore requires attention in