Ornamental Aquatics

en Brewers’s spent grains as an economical alternative to fishmeal in goldfish (Carassius auratus) diet Brewers’s spent grains as an economical alternative to fishmeal in goldfish (Carassius auratus) diet تخصصي Special پژوهشي Research Cost-effective and nutritionally balanced diet is fundamental for successful ornamental fish farming. This study aimed to investigate replacement level of fishmeal with brewer’s spent grain (BSG) in the diet of Carassius auratus to reduce production cost. A control diet was formulated to contain 40% crude protein and 21 kJ g⁻¹ of gross energy. Three experimental diets were formulated by replacing 10%, 20%, and 30% of fishmeal in the control diet with BSG. Using a completely randomized design, 120 fish (1.13±0.06 g) were assigned to 12 concrete-glass tanks (70×30×30 cm) at the rate of ten per aquarium, representing three tanks for each diet. The fish were fed twice a day (08:00 am and 03:00 pm) until satiation for six weeks. Water quality parameters were measured daily and maintained within the standard range. At the end of the experiment, fish survival was 95%. Length and weight gains of fish fed the experimental diets were higher (p<0.05) than those fed the control diet. Polynomial regression curves delineated the maximum length gain at 18.5% replacement of fishmeal with BSG while the maximum weight gain was at 9.6%. However, daily feed intake and feed conversion ratio did not differ (p>0.05) among the dietary groups. Condition factor of fish was significantly higher (p<0.05) in the treated groups. The estimated cost per kilogram feed showed a decreasing trend towards increasing level of BSG in the diet. In conclusion, 18.5% dietary BSG with the expense of fishmeal improved the growth of goldfish and reduced the feed cost. Further studies are recommended to investigate nutrient utilization and immunity of fish.   Cost-effective and nutritionally balanced diet is fundamental for successful ornamental fish farming. This study aimed to investigate replacement level of fishmeal with brewer’s spent grain (BSG) in the diet of Carassius auratus to reduce production cost. A control diet was formulated to contain 40% crude protein and 21 kJ g⁻¹ of gross energy. Three experimental diets were formulated by replacing 10%, 20%, and 30% of fishmeal in the control diet with BSG. Using a completely randomized design, 120 fish (1.13±0.06 g) were assigned to 12 concrete-glass tanks (70×30×30 cm) at the rate of ten per aquarium, representing three tanks for each diet. The fish were fed twice a day (08:00 am and 03:00 pm) until satiation for six weeks. Water quality parameters were measured daily and maintained within the standard range. At the end of the experiment, fish survival was 95%. Length and weight gains of fish fed the experimental diets were higher (p<0.05) than those fed the control diet. Polynomial regression curves delineated the maximum length gain at 18.5% replacement of fishmeal with BSG while the maximum weight gain was at 9.6%. However, daily feed intake and feed conversion ratio did not differ (p>0.05) among the dietary groups. Condition factor of fish was significantly higher (p<0.05) in the treated groups. The estimated cost per kilogram feed showed a decreasing trend towards increasing level of BSG in the diet. In conclusion, 18.5% dietary BSG with the expense of fishmeal improved the growth of goldfish and reduced the feed cost. Further studies are recommended to investigate nutrient utilization and immunity of fish. Low-cost feed, Calico Ryukin, Ornamental fish, SGR Low-cost feed, Calico Ryukin, Ornamental fish, SGR 53 64 http://ornamentalaquatics.ir/browse.php?a_code=A-10-307-1&slc_lang=en&sid=1 M.S.M. Nafees .M.S.M Nafees nafeezm@esn.ac.lk 10031947532846003691 10031947532846003691 Yes Faculty of Agriculture, Eastern University, Sri Lanka Faculty of Agriculture, Eastern University, Sri Lanka W.M.P. Chathuranga .W.M.P Chathuranga PrabathWijekoon61@gmail.com 10031947532846003692 10031947532846003692 No Faculty of Agriculture, Eastern University, Sri Lanka Faculty of Agriculture, Eastern University, Sri Lanka P.A. Shiromiya .P.A Shiromiya shiromie1997@gmail.com 10031947532846003693 10031947532846003693 No Faculty of Agriculture, Eastern University, Sri Lanka Faculty of Agriculture, Eastern University, Sri Lanka