الفهرس | Only 14 pages are availabe for public view |
Abstract The study was carried out to evaluate the effects of dietary supplementation of exogenous enzymes (protease or carbohydrases) at o.1gm/kg on growth performance, whole body composition, serum metabolities and enzymes activity of Nile tilapia fingerlings. One hundred ninety six (196) Nile tilapia fingerlings were allocated to seven dietary treatment groups. Each treatment was duplicated and had an average body weight of 10.14 gm/fish and ranged from 8 to 11 gm. Nile tilapia fingerling groups were fed control diet (G1) contained 32% CP and 3000 kcal DE/kg, group 2 (G2) control diet supplemented with protease enzyme, group 3 (G3) control diet supplemented with NSPases enzymes (β-glucanase, β-mannase, xylanase, pectinase, cellulase and hemicellulase), group 4 (G4) low CP diet (30%), group 5 (G5) low CP diet (30%) supplemented with protease, group 6 (G6) low DE diet (2900 kcal/kg) and group 7 (G7) low DE diet (2900 kcal/kg) supplemented with NSPases for aperiod of 84 days. Growth performance (body weight (BW), body weight gain (BWG), feed consumption (FI), feed conversion ratio (FCR), protein efficiency ratio (PER) and specific growth rate (SGR)), whole body composition (moisture, crude protein, ether extract and ash), serum metabolities (total protein, albumin, globulin, creatinine and urea) and enzymes activity (ALT and AST) were determined. Also, fish were taken randomly from each group for histological examination of some organs. The results indicated that control diet supplemented with NSPases enzymes (G3) significantly (p<0.05) improved growth performance parameters of Nile tilapia fingerlings (BW, BWG, FCR). In conclusion, supplementation of carbohydrases enzymes to the control diet (32% CP and 3000 kcal DE/kg) had a significant effect on body weight and body weight gain and decreased feed conversion ratio. Also, Nile tilapia can tolerate diets with low CP (30%) and low DE (2900 kcal/kg diet) supplemented with protease and carbohydrases respectively. |