THE USE OF TOMATO SEEDS BY-PRODUCT MEAL SUPPLEMENTED WITH L. CARNITINE AS NON-CONVENTIONAL INGREDIENTS IN PRACTICAL DIETS FOR MONOSEX NILE TILAPIA, Oreochromis niloticus

The present study was designed to evaluate the effect of replacing the protein source of soybean meal (SBM) by tomato seeds by-product meal supplemented with biogenic L. carnitine as a source of methionine plus lysine mixture (TSBPM) at a rate of 100mg/100g diet on growth performance, feed utilization and economic efficiency. Six experimental diets were formulated, control diet (T₀)  contained 45.4% soybean meal.  Tested Diets (T₁ -T­₅) contained 15 to 75% replacing levels (in 15% increments) of soybean meal protein(SBM) by tomato seeds by-product meal supplemented with L-carnitine (TSBPM).  All experimental diets were isonitrogenous (30% CP) and isocaloric (290.0 Kcal digestible energy/100g diet) and P/E ratio of 68.0 mg protein/Kcal gross energy) and each diet was fed to three replicated of fish groups (20 fish for each replicate).  Diets were fed to monosex Nile tilapia (O. niloticus) 6 days/week (twice daily) at 5% of live body weight through 120-days (experimental period).Results of this study showed that, replacement of SBM by tomato seedss by-product meal (TSBPM) up to 60% significantly improved final body weight (BW).  Increasing  the  replacing levels of SBM by TSBPM up to 75%  decreased daily weight gain (DWG), specific growth rate (SGR), total feed intake (FI), feed conversion ratio (FCR) and protein efficiency ratio (PER) with insignificant differences (P > 0.05)  compared with the control group.  These results revealed the possibility of replacing 75% of the high cost SBM by the low cost TSBPM in monosex Nile tilapia diets.
Results of body composition indicated that ,fish group fed diet  TSBPM₆₀ gained the highest percentages of protein content and the lower values of ash content, while the replacement of 75% of SBM by TSBPM released the lower percentages of protein, fat and dry matter contents, and higher ash content  in whole fish bodies, with significant differences (P < 0.05) compared with control treatment.
From the economic point of view, replacing 75% of SBM by TSBPM in mono sex Nile tilapia diets reduces feed costs by 40.73%.