الفهرس 
Technical and Economic Evaluation of Meagre (Argyrosomus regius) Farmed in Marine EnvironmentOnly 14 pages are availabe for public view
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Abstract
Summary and Conclusion The aim of the present study was to evaluate the effect of different location, feeding type, dietary protein levels with different rearing density and culture methods on survival (%), growth performance, feed utilization, fish yield, and economic evaluation on meagre, Argyrosomus regius fingerlings reared under different fish culture systems.This study took place in 2016-2017, carried out in collaboration with two private fish farms located at Wadii mariout, Mariout lake and Mount of dibah, El manzalah lake, Egypt. To achieve these goals were conducted four experiments using earthen ponds, net-enclosures and cages district as follows:-Experiment (1):- Effect of different location on survival (%), growth performance, feed utilization, fish yield, and economic evaluation on meagre, Argyrosomus regius.The present study was carried out at two different farm locations (Wadii Mariout, Mariout lake, and Mount of Dibah, El Manzalah lak). This experiment started on April 16th, 2016 and continued for 300 days, using two treatments with three replicates of earthen ponds. Each pond (6300 m2) with a depth about 1.5 m, was stocked with 5000 meagre fingerlings, with initial average weight was (104.05g) and the average initial length of (20.14cm). Meagre were fed 2 times per day trash fish (TF) (unmarketable tilapia that obtained from the fish market of Damietta and Kafr Elsheikh) with crude protein (62.36%) based on dry matter. All earthen ponds were sampled weekly using a cast net method. Sample sizes were 1% of the stocked numbers and the average individual fish weight was calculated to determine growth rates. Then, with these calculations, the feed amounts were adjusted for the following week.The results indicated the following:1-Body weight was increased significantly (P<0.01) with water located at Mount of Dibah to 1152.14 g/fish. While were (1134.44g/fish) at Wadii Mariout location.2-Feed conversion ratio (FCR), protein efficiency ratio (PER), Protein productive value (PPV%), Energy utilization (kcal/100g) were not significant for both of locations.
3- Survival (%) at Wadii Mariout was 78.71% while, it was 82.17%, at Mount of Dibah.
4- Net return arrived to 279370 LE/ pond for Wadii Mariout location, when it was 298685 LE/ pond for Mount of Dibah location. 5-There was a significant difference of natural food found in the stomach of meagre, Argyrosomus regius, Asso1801 at both of the location Wadi Mariot and El manzala Lake. Experiment (2):- Effect of different feeding types on survival(%) growth performance, feed utilization, Serum biochemical analyses and Histological examination, economic evaluation on meagre, Argyrosomus regius, Asso1801 reared in net-enclosures,This experiment was carried out at Mount of Dibah, Damietta governorate, started on May 23th, 2017 and continued for 70 days. Two compared feeding treatment (trash fish (TF) (unmarketable tilapia (62.36% crude protein) and artificial diets (AF) demersal commercial pelleted diets, (39.91% crude protein) based on dry matter), each treatment was triplicate, using net-enclosures 1m3. Meagre fingerlings, with average weight (7.58 gm) and (8.20 cm) average total length were stocked at a stocking rate of 50 fingerling / m3) and were fed 3 times daily. The results indicated the following:1- Body weight was increased significantly (P<0.05) with artificial diets to 128.49 g/fish. while were (89.87g/fish) for trash fish diets.2- Specific growth rates (SGR %) increased with artificial diets compared to trash fish diets.
3- Feed conversion ratio (FCR), protein efficiency ratio (PER), Protein productive value (PPV) Energy gain (Kcal) and Energy utilization (kcal/100g) were significantly improved with Artificial diets.4- Survival (%) with trash fish diets were 70.20 %, while it was 61.33% with artificial diets.
5- Body composition were affected significantly by feeding type treatments. It was 64.07 % protein, 20.39% Ether extract and 553.8 Carcass energy (kcal/100g) at trash fish diet, while it was 65.81% protein, 19.13% Ether extract and 551.75 Carcass energy (kcal/100g) at artificial diet. 6-The beneficial effects of using artificial diet on meagre growth appear to be associated with higher protein retention and lower lipid content.
7- The artificial diet marked improvement of hepatic and intestinal tissues, liver showed marked increase in cytoplasmic eosinophilia in their cytoplasm accompanied with decrease fat content. Also, The intestine demonstrated marked increase in length of villi in addition to increase the branches and increase number of goblet cells within lining epithelium. 8-The results indicate that artificial diet has some ability to activate the immune system of meagre by increasing serum total protein.
9- Net return arrived to 170.10 LE for trash fish diet when it was 251.60 LE for artificial diet.Experiment (3):- Effects of stoking density and dietary protein levels on survival (%) growth performance, feed utilization, Serum biochemical analyses and economic evaluation on meagre, Argyrosomus regius reared in net-enclosures,Eighteen treatment net-enclosures 3 × 2 factorial design three rearing densities (20, 40 and 60 fish/m3) with two levels of dietary protein (40% and 45%) and three net-enclosures were assigned for each treatment. Water volume in each net-enclosures was 1 m3. The present experimental was carried out Mount of Dibah, Damietta governorate. started on Jun 11st, 2017 and continued for 84 days.
Three stoking densities (20, 40 and 60 fingerlings / m3) with initial average weight was 20.69 g/fish. Two experimental demersal commercial diets contain of (39.91 and 44.89%) crude protein(CP). Three replicates per each treatment. Meagre were fed 2 times a daily on commercial pelleted diets with diameters (4mm). The results indicated the following:1- Body weight was increased significantly (P<0.05) with 20 fish/m3 and 45% protein level to 256.15 g/fish. While were 232.15 g/fish with 40 % protein level at the same stoking density, 215.83 and 239.43 g/fish with 40 fish/ m3 with 40 and 45% protein level respectively, However, it was 168.79 and 197.56 g/fish with 60 fish/ m3 for 40 and 45% protein level respectively. And were significantly affected by protein-density interaction (P > 0.05).2- Specific growth rates (SGR %) increased with 20 fish/m3 with 45% protein level compared to 40 and 60 fish/m3 with 40and 45% protein level. And were significantly affected by protein-density interaction (P > 0.05).3-Feed conversion ratio (FCR), protein efficiency ratio (PER), Protein productive value (PPV%) and Energy utilization (%) were significantly improved with 20 fish/m3 and 45 % protein level than the other two treatments 40 and 60 fish/m3 with 40and 45% protein level.4- Survival (%) with 20 fish/m3 with 45% protein level was the highest survival (%) at this experiment.
5- Body composition were affected significantly by stoking density and protein level treatments. It was the best 58.88 % protein, 22.25% Ether extract and 542.12 Carcass energy (kcal/100g) at 20 fish/m3 and 45% protein level, while it was lower at the other treatments. 6-RBCs, Hb, plasma protein, plasma lipids, and plasma cortisol values were significantly affected by protein level and rearing density only; meanwhile, plasma glucose, AST, and ALT were significantly affected by protein level, rearing density, and their interaction (P < 0.05).7- Net return arrived to 470.94 LE for (20 fish/m3 with 45% protein level) when it was lower at the rest of the other treatments.
Experiment (4):- Effect of different culture methods (earthen ponds and cages) on survival (%) growth performance, feed utilization, fish yield, and economic evaluation on meagre, Argyrosomus regius, Asso1801,
This experiment was carried out at Wadii mariout, privet fish farm at Alexandria governorate, started on April 9th, 2016 and continued for 300 days using two culture method treatments (Earthen ponds- Cages) with three replicates. each pond(90 m length * 70 m width *1.5 m depth) stoked with 5000 with initial average weight was (102.78g), average initial length of (20.10cm). And each cage (20 m long, 10 m width and 2 m height) stoked with 1000 meagre fingerlings with initial average weight was (105.00 g) and average initial length of (20.11cm).
Fish were fed 2 times daily on trash fish (TF) (unmarketable tilapia that obtained from the fish market of Damietta) with Crude protein (62.36%) based on dry matter. All earthen ponds were sampled weekly using a cast net method. Sample sizes were 1% of the stocked numbers and the average individual fish weight was calculated to determine growth rates. Then, with these calculations, the feed amounts were adjusted for the following week.
The results indicated the following:
1- Body weight was increased significantly (P<0.05) with culture methods for cages to 1537.55 g/fish. While were 1134.44 g/fish for earthen ponds.
2- Specific growth rates (SGR %) increased with cages (0.89 %/day) compared to earthen ponds (0.80 %/day) and were significantly at (P ≤ 0.01) 3-Feed conversion ratio (FCR), protein efficiency ratio (PER), Protein productive value (PPV%) Energy gain (Kcal) and Energy utilization (kcal/100g) were significantly improved in fish reared in cages.4- Survival (%) for fish in cages were 89.39%, while, was 78.71% in earthen ponds.5-Net return arrived to 84788 LE with cages, when it was 279370 LE with earthen ponds.
Finally, the results of present study showed that Mount of Dibah at El manzala lake location feeding meagre, Argyrosomus regius, Asso1801 on artificially pellet diet, and using 20 fish/m3 as stocking density with 45% dietary protein level, and using cages as culture methods which enhance growth, feed utilization, body composition and economical feasibility for achievement of optimal farming productivity with high economical profits.