Determination of growth and nutritional composition of nile tilapias (O. niloticus) fed with L-glutamic acid supplemented feeds

In this study, it was tried to determine the growth performance and body chemical composition of Nile tilapia (O.niloticus) fed with different levels of L-Glutamic acid supplementation. In the experiment, 4 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). For this purpose, tilapia fry with an average initial weight of 4.86 g were stocked into 12 fiber tanks (450L) with 40 individuals and 3 replications under controlled conditions, and the experiment was continued for a period of 60 days. At the end of the experiment, 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), average daily growth (ADG; 4.95±0.20) protein efficiency ratio (PER 2.83±0.10) and net protein utilization (NPU; 61.62±3.39) were higher than the other groups (P<0.05). When the nutritional composition data were evaluated, it was determined that protein, dry matter and fat compositions differed between the groups (P<0.05). The highest whole body protein level was found in the G2 group with a value of 21.24±0.52, while the lowest protein level was found in the control group with a value of 20.17±0.15. When all the data obtained are evaluated, it has been shown that adding 2% L-Glutamic acid to the feed of juvenile Nile tilapia (O.niloticus) can be recommended both in terms of growth and development of the fish and their nutritional composition.