Israeli Journal of Aquaculture - Bamidgeh, cilt.75, sa.2, 2023 (SCI-Expanded, Scopus)
The study aimed to assess Nile tilapia’s (Oreochromis niloticus) growth performance and body chemical composition through varying levels of L-Glutamic acid supplementation. In the experiment, four different groups of feed were prepared; the control C (0% L-Glutamic acid), G1 (1% L-Glutamic acid), G2 (2% L-Glutamic acid), and G3 (3% L-Glutamic acid). Tilapia juveniles with an average initial weight of 4.86 g were stocked into 12 fiberglass tanks (450L) with 40 individuals and three replications under controlled conditions, and the experiment was continued for a period of 60 days. At the end of the experiment, for the G2 group final weight (FW, 19.31±0.59 g), specific growth rate (SGR; 2.30±0.05), feed conversion ratio (FCR; 1.02±0.03), daily growth rate (DGR; 4.95±0.20) protein efficiency ratio (PER 2.83±0.10) and net protein utilization (NPU; 61.62±3.39) were better than the other groups (P<0.05). Nutritional composition data showed that the groups differed between protein, dry matter, and lipid compositions. The G2 group exhibited the highest whole-body protein level, recording a value of 21.24±0.52, whereas the control group demonstrated the lowest protein level at 20.17±0.15. In conclusion, incorporating 2% L-Glutamic acid into the diet of juvenile Nile tilapia is advisable for both the growth and development of the fish and for enhancing their nutritional composition.