Journal of Advances in Biology & Biotechnology

The purpose of this research was to find promising alternative ingredients which partially replace expensive GNOC for formulation of cost effective feed having better growth and feed efficiency of GIFT tilapia and optimise extruder parameters for the preparation of floating fish diets with appropriate physicochemical qualities. Accordingly, four iso-nitrogenous (crude protein 35%) experimental diets were formulated for GIFT tilapia advance fry by replacing 50% of GNOC protein of the control diet (T₀) by sunflower oilcake (SFOC) (T₁), by linseed oilcake (LSOC) (T₂) and by fish based silage (T₃) protein. The pellets extruded using a combination of 120 ^oC extruder barrel temperature, 25% moisture content of feed mix, 2.0 mm die diameter and 30 minute of pre-conditioning time. Results of the feeding trial using one hundred twenty number of GIFT tilapia advance fry of average weight 1.20 ± 0.34 g reared in twelve number of 200L FRP tanks under continuous aeration and fed with above four experimental diets in triplicate concluded that SFOC can be used to partially replace GNOC in floating fish feed without significantly (P<0.05) affecting the growth performance of GIFT tilapia, where as LSOC incorporation had a negative impact on the growth performance and feed efficiency parameters. However, fish silage when incorporated in the GIFT tilapia diet by partially replacing GNOC, it resulted in significantly higher growth rate (474.2 % weight gain) and better feed efficiency parameters of 2.27 FCR and 1.26 PER. Hence, fish silage and SFOC are promising alternative ingredients to partially replace expensive GNOC for formulation of cost effective feed for better growth and feed efficiency of GIFT tilapia.