This study aimed to improve the nutritional value and utilization of sunflower meal (SFM) used as feed ingredient for tilapia by an approach of solid-state fermentation with Saccharomyces cerevisiae. The protein content and lipid content was increased, while phytic acid and trypsin inhibitor were decreased during fermentation. Dietary fish meal was replaced with yeast fermented sunflower meal (YFSFM) in four isonitrogenous (297 g/ kg crude protein and isocaloric 19.6 MJ/ kg gross energy) diets. Fish meal was replaced with YFSFM in the experimental diets in four levels 0, 25, 50 or 75% to formulate four experimental diets (control diet), D1, D2, D3 and D4, respectively. Each diet was fed to triplicate groups of fish with an initial weight 10.30 ±0.12 g for 84 days. The highest final body weight (FBW), weight gain (WG), specific growth rate (SGR) and the best condition factor (K) were obtained with D1 and D2. The lowest growth response was obtained with D4. Generally, a positive protein substitution effect was observed at 25% substitution levels (D2). The highest feed intake (FI) g/fish and the best feed conversion ratio (FCR) and protein efficiency ratio (PER) were recorded for fish fed D1 and D2, with values statistically different from the other treatments. Fish fed different levels of YFSFM did not have a significant impact on dry matter, lipid, crude protein and ash contents of the fish. |
