Determination of optimum levels of energy and protein on pacific white shrimp (Litopenaeus vannamei) diet at marketing stage

To investigate an economical diet for white pacific prawn (Litopenaeus vannamei) rearing coastal zones of south Iran, 9 experimental diets were prepared considering three protein (37%, 37%, 40% CP) and three digestible energy (262, 312, 362 kcal. 100g^-1 DE) levels, using herbal protein source (soybean meal) as main protein source for the diets. 27 polyethylene round tanks (300 L volume) provided with aerated flow-through water system, stocked with …juvenile shrimps (9.16 ± 0.05 g mean weight) were applied to evaluate the growth performance of the shrimps and feed efficiency parameters of the diets for 8 weeks rearing period in an in-door experimental system. Results showed the diets were significantly different (P≤0.05)in the terms of growth performance and diet efficiency the shrimp, while the best obtaining observed in diet 1 (34% CP and 262 kcal. 100g^-1 DE). Average of weight gain was ranged from 4.58 ± 0.52 g in Diet 9 up to 6.88 ± 0.81 g in diet one, SGR was from 0.73 ± 0.06 in diet 9 to 1.00 ± 0.09 in diet one, survival was from 75.00 ± 7.07 % in diet 9 to 95.00 ± 5.00 % in diet one and FCR was from 5.02 ± 0.94 in diet one to 8.24 ± 1.59 in diet 9. Diets did not effectively influenced the body composition of the shrimp (P>0.05). According to the results of the present study, 34% Cp and 262 kcal. 100g^-1 DE could be suggested as suitable levels to be considered in the diet of the white pacific prawn in the grow-out stage

Feasibility of mass cultivation on Nannochloropsis oculata microalgae in tubular culture system

The presnt study has been carried out to evaluate the Nannochloropsis oculata culture performance in 100L columnar plastic bags under two chemical media (TMRL and CONWAY) and 3 light regimes in the controlled conditions. Algae used for the experiment has been provided through culture of primitive stock and by transferring it to 2 L glassy erlenmeyer and 15 L plastic containers (as intermediate stage) using CONWAY media respectively. Daily evaluation of algae concentration was carried out during the 18 days culture period. At the end of the study produced algae has been sedimented to be used for evaluation of the dried matter and algae biomass. Results of the study showed that the concentration of the algae culture was 22±3.34×106 cells. ml^-1, at 8th day, and reached the concentration of 26.58±4.02×106 cells. ml^-1 at the final day of the culture course. Although the results revealed the possibility of achievement of acceptable concentration for the N.oculta by the method adopted in the present study, but the achievement was not such favourable to be considered as an altenative for the common method. Nevertheless it could be considered as an alternative for the constrained situations. Moreover according to the results there was no significant algae concentration difference between light regimes (P>0.05). Similar results were observed for the interaction effect of chemical media and light regimes. Meanwhile the ratio of dried matter obtained from algae under the TMRL media was significantly (P0.05) affect the algae production. Finally it could be concluded that the N.oculata algae could be successfully cultured in plastic columnar bags under the controlled conditions but the method adopted in the present study could be applicable in the improper conditions

Growth Performance, Hemato-Immunological Responses, and Digestive Enzyme Activities in Silvery-Black Porgy (Sparidentex hasta) Fed Dietary Bovine Lactoferrin

An 8-week study was conducted to evaluate three different diets supplemented with bovine lactoferrin (LF) at 0 (control), 800, and 1200 mg LF kg−1 diet on somatic growth, hemato-immunological parameters, antioxidant status, and digestive enzyme activities in silvery-black porgy (Sparidentex hasta) juveniles. Fish fed the 800 mg LF kg−1 diet had higher growth performance and feed utilization parameters than the other groups. Hematological and liver antioxidant parameters were not affected by dietary LF supplementation. Fish fed the 800 mg LF kg−1 diet had higher plasma lysozyme activity values than the other groups. Total protease activity was higher in fish fed LF-supplemented diets than the control group. Results indicated that diet supplemented with 800 mg kg−1 for 8 weeks enhanced somatic growth performance, lysozyme activity, and proteolytic digestive enzyme activities in S. hasta, as well as improving feed efficiency parameters like the protein efficiency and feed conversion ratios.info:eu-repo/semantics/acceptedVersio

Feasibility on cage culture of the orange-spotted grouper (Epinephelus coioides)

The present study was carried out to evaluate the possibility of rearing the orange-spotted grouper (E. coioides) juvenile to marketable size in buoyant cages in Khuzestan province coast waters. Juvenile fishes for the study prepared from Bandar-e-Imam Marine Fish Station and reared them in 5-ton fiber glass tank for one year period using common pellet feed and trash fish to reach 50 g mean weight. Young fishes were stocked in 6 rectangular cages (3×3×3 m) to assess their growth performance with two test feeds i.e. pellet feed and trash fish (3 cages for each treatment) with the density of 30 fish /m^3 (810 fish/cage) for 143 days rearing period (started on July). Better growth with significant difference (p0.05). Results also showed that the FCR for the trash fish was acceptable, and hence it is recommended to consider the trash fish price and its labour cost befor using it as the main diet in cage culture activity

Macronutrient Requirements of Silvery-Black Porgy (Sparidentex hasta): A Comparison with Other Farmed Sparid Species

Silvery-black porgy (Sparidentex hasta) is recognized as one of the most promising fish species for aquaculture diversification in the Persian Gulf and the Oman Sea regions. In this regard, S. hasta has received considerable attention, and nutritional studies focused on establishing the nutritional requirements for improving diet formulation have been conducted during recent years. Considering the results from different dose–response nutritional studies on macronutrient requirements conducted in this species, it can be concluded that diets containing ca. 48% crude protein, 15% crude lipid, 15% carbohydrates and 20 KJ g−1 gross energy are recommended for on-growing S. hasta juveniles. In addition, the optimum essential amino acid profile for this species (expressed as g 16 g N−1), should be approximately arginine 5.3, lysine 6.0, threonine 5.2, histidine 2.5, isoleucine 4.6, leucine 5.4, methionine + cysteine 4.0 (in a diet containing 0.6 cysteine), phenylalanine + tyrosine 5.6 (in a diet containing 1.9 tyrosine), tryptophan 1.0 and valine 4.6. Moreover, the optimum dietary n-3 long chain polyunsaturated fatty acids and soybean lecithin are recommended to be 0.8% and 6%, respectively. The maximum replacement of fish meal with soy protein is recommended to be between 16.5% and 27.3%. In addition, different vegetal oil sources are also recommended for partial and almost complete replacement of fish oil in diets. Although the nutritional requirements in terms of macronutrients have been established under laboratory conditions, the analysis of the available literature indicate that future studies need to be conducted using a more holistic approach under intensive farming conditions in which different nutrients or additives need to be tested under different rearing conditions for refining nutrient requirements in this species

Dietary soybean lecithin affects growth performance, fillet biochemical composition and digestive enzyme activity in Sparidentex hasta juvenile

An eight-week study was conducted on silvery-black porgy (Sparidentex hasta) juveniles to evaluate four isoproteic, isolipidic and isoenergetic different diets (50% crude protein, 20% crude lipids, 18.5 MJ kg−1) containing graded levels of soybean lecithin (SBL) (0, 30, 60 and 90 g kg−1 diet) at the expense of fish oil (FO). Fish fed the 60 g SBL kg−1 diet had significantly higher weight gain (32.4%) and feed intake (8.8 g fish−1) than the control group (SBL 0) (P < 0.05). The fillet fatty acid (FA) profiles were correlated with the FA profile of the experimental diets. Fish fed with SBL-supplemented diets had higher fillet phosphatidylcholine levels than the control group (P < 0.05). Plasma total immunoglobulin was higher in fish fed 60 and 90 g SBL kg−1 diets than in the other groups (P < 0.05). Total protease activity was higher in fish fed the 90 g SLB kg−1 diet than other treatments (P < 0.05). Results indicated that substitution of dietary FO with SBL diet up to 67% (60 g SLB kg−1 diet) improved somatic growth performance and profoundly affected the fillet fatty acid profile in silvery-black porgy juveniles