Preetha VV *,Belayneh A ,Palavesam A ,Immanuel G ,Tadesse Z
Effect of dietary nutrient source like, fishmeal (F1), soymeal (F2), casin (F3) and groundnut oilcake (F4) on nitrogen and phosphorus loading during culture of tiger shrimp, Penaeus monodon was assessed. Healthy shrimps (PL 25) with average body weight of 20.3 ± 0.3 mg were reared in 200 litre capacity FRP tanks containing 150 litre filtered seawater (20 ppt salinity) at the stocking density of 15 individuals/tank with well aeration in triplicate. Shrimps were fed with the experimental diets four times per day at adlibitum and the unfed remains were collected daily in the early hours and dried in an oven at 80°C. The growth of P. monodon was found to be greater (2.43 ± 0.07 g) with better FCR (1.71 ± 0.03) and SGR (5.33 ± 0.18%) on F1 diet. Total nitrogen losses were high in shrimps reared in F3 diet (73.34 ± 0.78 mg) whereas total phosphorus losses were high in F1 diet (37.279 ± 0.590 mg). Nitrogen loss per gram of shrimp produced and per gram of feed consumed showed maximum value (48.51 ± 0.49 and 23.21 ± 0.41 mg/g) in F3 diet fed group followed by other diets groups. Phosphorus loss per gram of shrimp produced and feed consumed were high in F1 diet fed shrimp. Total phosphorus loading (kg/t) based on shrimp production showed high value (15.34 kg/t shrimp produced) in F1 diet fed group, whereas it was low (1.087 kg/t shrimp produced) in F3 diet group. Total nitrogen loading based upon shrimp production showed maximum loading (48.5 kg/t shrimp produced) in F3 diet group and minimum value (20.2 kg/t shrimp produced) in F2 diet group. Therefore, in shrimp farming there is a need for consideration of availability of proper meal proportionate, nutritionally complete, cost-effective and aquaculture friendly green formulated feeds in order to achieve better productivity and aquaculture sustainability.