Intensive polyculture of fish in freshwater ponds. I. Substitution of expensive feeds by liquid cow manure

In 1974 and 1975 nine experimental treatments of fish polyculture in stagnant water ponds without aeration were conducted at Dor. The polyculture was composed of common carp, silver carp, white amur (grass carp) and Tilapia. The treatments differed in stocking densities, feeding and manuring levels. The most productive treatment of the experiment, in which the fish were fed with protein-rich pellets, produced 50 kg/ha per day, probably a record for unaerated ponds of stagnant water. Two treatments (low and high stocking densities) fed exclusively with liquid cow manure produced an average yield of around 32 kg/ha per day. The yields of the treatments receiving high-protein pellets exceeded those of the treatments receiving grain pellets by 20 and 9.6 kg/day per ha, at high and low stocking densities, respectively, and in both cases the yield increments justified the extra cost of high-protein feed. The responses of the four fish species to the different levels of feeding and stocking densities were widely different. The common carp and white amur showed the greatest responses to increased feeding inputs while the silver carp and Tilapia, even at high densities, have done equally well at low feeding levels. Total body fat contents of the common carp were 20%, 15% and 6.2% when fed with high-protein pellets, grains pellets and liquid cow manure, respectively. Intermittent harvesting did not result in increased yields.     

Effect of substitution of maize bran with chicken manure in semi-intensive pond culture of Tilapia rendalli (Boulenger)

An experiment was carried out to determine the effect of substituting maize bran with chicken manure on the production of Tilapia rendalli semi‐intensive pond culture. The experiment was carried out at Bunda College of Agriculture's fish farm, University of Malawi, where twelve 20 m² concrete ponds of 1 m depth were used for 3 months from October 2005 to January 2006. A thin layer of soil was spread at the bottom of all ponds to allow growth of natural food. Each pond was stocked with 3 fish m⁻² of 10.71 g average weight. Chicken manure was used as the organic manure applied at 1.6 kg 20 m⁻² and substituted for maize bran by 25%. All treatments were replicated three times. It was observed that fish growth was higher in the 3/4 maize bran+1/4 chicken manure with a final weight of 25.1 g, followed by 1/4 maize bran+3/4 chicken manure with a final weight of 21.6 g. The lowest final weight was 19.3 g in the chicken manure only, but did not differ significantly (P<0.05) from the maize bran treatment, which had a final weight of 19.7 g. This suggests that the use of chicken manure would produce better results and may increase yield when combined with supplementary feed like maize bran evidenced by high survival rates of 80% and above in all treatments.     

Effect of Using Low-Protein Diets in Semi-Intensive Pond Cage Culture of Tilapia,Tilapia rendalli (Boulenger)

ABSTRACT

An experiment was carried out to determine the effect of using low-protein diets on production of Tilapia rendalli in semi-intensive pond cage culture. This was carried out at Bunda College of Agriculture's fish farm, University of Malawi, where two 200-m² earthen ponds of 1-m depth were used for two months from February 2003 to early April 2003. Each pond had 6 cages of 1 m³ in size stocked with 15 fish, each 4.8 ± 1.2 g average weight and 6.7 ± 0.6 cm average length. Chicken manure was used as the organic manure applied at 500 kg/ha/wk and also acted as a control. All treatments were replicated three times. It was observed that fish growth was higher in the soybean meal-based diet, with final weight of 34.4 g, followed by sunflower cake, with final weight of 23.3 g. The lowest was 14.4 g in the chicken manure only, and cottonseed-based diet had final weight of 19.5 g. These results also agree with the specific growth rate (SGR) that ranged from 2.1%/day in the cages only fertilized with chicken manure to 3.6%/day in the soybean-based dietary treatment. The lowest feed conversion ratio of 1.2 was also observed in the soybean-based dietary treatment. This suggests that the use of lower protein diets that contain soybean would produce better results and may increase yield when combined with fertilization, as evidenced by high fish survival rates of more than 93% in all treatments.     

Preliminary Comparisons of the Native Penaeus setiferus and Pacific P. vannamei White Shrimp for Pond Culture in South Carolina, USA

Two pond experiments were conducted at the Waddell Mariculture Center to compare production characteristics of the native Penaeus setiferus and Pacific P. vannamei white shrimp in South Carolina. In 1985, 7–9 day old postlarval P. setiferus were stocked in one 0.1 and one 0.25 ha ponds, while P. vannamei of the same age were stocked in one 0.1 and one 0.25 ha ponds, while P. vannamei of the same age were stocked in one 0.1, one 0.25, and one 0.5 ha ponds. Both species were stocked at 12 shrimp/m². The shrimp were fed a 25% protein commercial food and harvested by draining after 147 d. Sarvival in all ponds was > go%, but growth and production of the P. setiferus were considerably lower than values obtained for P. vannamei: 12.8 g and 1,555 kg/ha/crop for P. satiferus versus 19.7 g and 2,477 kg/ha/crop for P. vannamei. In 1989, duplicate 0.1 ha ponds were stocked with P. setiferus and P. vannamei at 60 shrimp/m², and two additional 0.1 ha ponds were stocked with P. setiferus at 40/m². The P. setiferus postlarvae were produced at the Waddell Center from captive-reared and wild South Carolina brood stock. Rearing procedures involved paddlewheel aeration (10 hp/ha), regular water exchange (averaging 16–21%/d in all ponds), and use of a 40% protein feed. Due to the availability of postlarvae, the various treatments were stocked at different times. Both P. setiferus treatments were reared for 145 d, while the P. vannamei were reared for 165 d. P. setiferus at the 40/m² density attained mean size, survival, and standing crop biomass at harvest of 13.5 g, 97.5% and 5,259 kg/ha/crop, respectively. The 60/m²P. setiferus treatment was stocked 2 wk earlier and yielded 15.2 g mean weight, 87.5% survival, and 7,995 kg/ha/crop at harvest. The P. vannamei 60/m² treatment, which was stocked 3 wk earlier than any of the P. setiferus, produced mean size, survival and standing crop biomass at harvest of 17.1 g, 69.5% and 7,187 kg/ha/crop. Both survival and production levels would have been higher had not one replicate experienced a partial mortality due to a feeding accident. The 1989 study yielded what is thought to be the highest production levels yet achieved with P. setiferus in pond culture. These results suggest that P. setiferus may be a viable alternative to P. vannamei for intensive cultivation in the continental U.S. when P. vannamei are unavailable. Further evaluation of this potential is needed.     

Evaluation of Distillers Dried Grains with Solubles as an Ingredient in Diets for Pond Culture of the Freshwater Prawn Macrobrachium rosenbergii

Distillers dried grains with solubles (DDGS) were evaluated as an ingredient in practical diets for pond culture of the freshwater prawn Macrobrachium rosenbergii . Juvenile prawns averaging 0.66 ± 0.47 g were stocked into nine 0.02 ha ponds at 19,760/ha. Three isonitrogenous diets (29% crude protein) containing 0, 20, or 40% DDGS were fed to shrimp in triplicate ponds. Average yield, survival, individual weight, and feed conversion did not differ significantly ( P > 0.05) among treatments. When averaged over the three diets, results were: yield, 833 kg/ha; survival, 75%; individual weight, 57 B; and feed conversion, 3.1. It appears that DDGS is a suitable ingredient for use in practical diets for freshwater prawns at levels of up to 40% of the total formulation, when prawns are stocked at the densities used in this study.     

Intensive Culture Potential of Penaeus vannamei

Tank and pond rearing studies were conducted to assess the potential for intensive culture of Penaeus vannamei in South Carolina. Postlarvae were stocked in intensive nursery tanks at 500/ m². Growth and survival were compared for shrimp reared in control fiberglass tanks and in tanks with artificial substrates (fiberglass screen). Addition of substrate improved survival (82% versus 58%), but not growth. Juvenile shrimp (mean weight, 1.3 g) from the nursery trial were stocked into 6 m diameter tanks at densities of 10, 20 and 40/m². Growth rate was inversely related to stocking density, with mean sizes of 33.9, 32.5, and 26.7 g attained at the low, medium, and high densities respectively after 168 days. At harvest, standing crop biomass averaged 225.6, 442.0, and 685.4 g/m² for the three densities. To further test the intensive culture potential, two 0.1 ha ponds were stocked with hatchery-reared postlarvae at densities of approximately 40 and 45/m². The ponds were managed intensively using paddlewheel aerators and water exchange averaging 16–17%/day. The ponds were harvested after 138 and 169 days and yielded 6,010 kg/ha of 16.7 g (mean weight) shrimp and 7,503 kg/ha of 17.9 g shrimp, respectively. Average production was 6,757 kg/ha with a food conversion of 2.51. These data suggest good potential for intensive pond culture of P. vannamei in South Carolina and other areas of the continental United States.     

Effect of stocking density on shrimp growth rates in manure-fertilized ponds

Ecuadorian Penaeus vannamei were cultured in eight 200-m² dirt ponds at four stocking densities (5, 10, 15 and 20 shrimp/m²). No commercial feed was given to the shrimp. The only input to the ponds was about 36 kg of feedlot cattle manure per pond per week (1800 kg manure ha⁻¹ week⁻¹).Shrimp growth was not correlated with variations in water quality among treatments (e.g., temperature, pH, DO, secchi visibility). Water-column nutrient levels were less than or equal to nutrients in incoming water and did not increase with addition of cattle manure. Water ATP concentrations were correlated with shrimp stocking density while numerous other biochemical parameters were not. No coliform bacteria were detected in any pond water samples during the study period. Phytoplankton densities and species composition were not different among treatments but varied over time. Two diatoms were the dominant species throughout the study.There was a negative correlation between stocking density and growth. Mean (±SD) weekly shrimp growth across treatments was 0.68±0.00, 1.06±0.02, 1.72±0.2 g individual⁻¹ week⁻¹ for densities of 20, 15, 10, and 5 shrimp/m², respectively. Survival averaged 70.8±6.3% for all ponds and was not different among treatments. Shrimp production was 19.3±0.1, 23.0±0.4, 22.8±1.2, 12.3±1.1 kg ha⁻¹ day⁻¹ for densities 20, 15, 10, and 5 shrimp/m², respectively. Shrimp production and carrying capacity were not significantly different among the three higher stocking densities.     

Comparative evaluation of the fertilizer value of human urine, cow manure and their mix for the production of carp fingerlings in small holding tanks

Advanced fry of Indian carps and post-larvae of freshwater prawn were reared for 120?days in 18 small holding tanks using each treatment in triplicate as: (a) non-aerated and (b) aerated fresh human urine (0.01%), (c) cow manure (1.8?kg tank^?1), mixed treatment with cow manure and human urine under (d) iso-phosphorus and (e) iso-nitrogenous conditions and (f) control. Examination of water quality, primary productivity of phytoplankton, plankton and fish growth from different treatments revealed that the total fish yield was maximum in the cow manure treatment (621.5?g?tank^?1) followed by the mixed treatments under iso-nitrogenous (428?g?tank^?1) and iso-phosphorus (333?g?tank^?1) conditions. Fish yield in different treatments was the direct function of the gross and net primary productivity of phytoplankton which, in turn, were directly related to the concentrations of nitrate and phosphate levels of water as well as their ratios in different treatments employed.     

Growth, Survival and Feed Conversion Rates of Sea Bream (Sparus aurata) Cultured in Earthen Brackish Water Ponds Fed Different Feed Types

Sparus aurata were cultured during an 8-month period in brackish water (salinity about 25 ppt) in an extensive culture system comprising eight earthen ponds, each with a water surface of 2.1 ha. Initial mean wet weight of fish in all ponds varied from 13.6 ± 1.9 to 19.2 ± 2.6 g/fish. The eight ponds were randomly allocated one of four experimental treatments (two ponds/treatment). In the first treatment, ponds were fertilized monthly with 100 kg urea and 50 kg triple super phosphate. The other treatments (2–4) were fed a locally produced tilapia pellet feed containing 25% crude protein made using different processes. Fish in the second treatment were fed tilapia feed pelleted by compressing machine, whereas in treatments 3 and 4 the pellets were produced by extruder machine (Wenger). Pellets in treatment 3 were floating and in the fourth were semi-sinking. Fish were fed pellets twice daily at 6% of their biomass. The mean final body weight for each treatment respectively was 104.6, 118.9, 156.8 and 158 g. Specific growth rate (SGR) of 0.8, 0.79, 0.99 and 0.95%/day, were obtained in ponds using only inorganic fertilizer, compressed sinking pellets, extruded floating pellets and extruded semi-sinking pellets, respectively. Feed conversion ratios (FCR) for treatments with the extruded tilapia pellets were 2.2 and 2.6 g feed/g gain, which were significantly (P < 0.05) better than treatments with compressed pellets (3.2 g feed/g gain). Production/ha/year were 1389, 1358, 945 and 682 kg fish for the groups fed with extruded floating, extruded semi-sinking, compressed and natural food, respectively. Under the present experimental circumstances, Sparus aurata fed extruded floating tilapia pellets (25% crude protein and 2,600 kcal/g), showed the best productive performance.     

The role of chicken manure in the production of Nile tilapia, Oreochromis niloticus (L.)

Abstract. Two grow-out experiments were conducted to evaluate the functional role of chicken manure for Nile tilapia, Oreochromis niloticus (L.). production in central Thailand. Experiment 1 examined the relationship between chicken manure input and net fish yield (NFY). Experiment 2 determined the value of chicken manure in providing tilapia particulate organic carbon, and/or dissolved inorganic carbon (DIC) for stimulating algal productivity. In both experiments supplemental urea and triple superphosphate (TSP) gave all treatments total nitrogen (N) and phosphorus (P) inputs of 28·0kg/ha/week and 7·0kg/ha/week, respectively.
Addition of chicken manure to inorganic fertilization did not enhance production of Nile tilapia. NFY in experiment 1 increased with decreasing manure loading, which corresponded to increasing TSP input. Regression analysis suggested that chicken manure-P was about 10% effective as TSP-P at increasing NFY. NFY was linearly correlated to net primary productivity (r²= 0·62, P < 0·001), which was linearly correlated to total alkalinity (r²= 0·77. P < 0·001).Treatment differences in alkalinity, community respiration or dissolved oxygen concentrations at dawn were not related to manure input. Simple economic comparisons discourage the purchase of chicken manure as a source of soluble N and P for increasing algal productivity in Thailand.     

The effect of dietary protein on the growth and survival of the shrimp, Penaeus monodon in outdoor tanks

The comparative effect of reducing the protein content of formulated feed on the growth and survival of black tiger shrimp, Penaeus monodon, and on water quality was tested in outdoor tanks. Three diets, 300, 350 and 400 g kg^?1 crude protein (CP), were fed to P. monodon (3.1 g animals, 25 animals per m²) in each of eight replicated outdoor 2500 L tanks in an 8‐week trial. There was no statistical difference (P > 0.05) in shrimp growth rate (1.34–1.50 g week^?1), survival, or final biomass between the treatments. However, when tanks with lower survival were removed from the analysis (<60 and <80% were tested), shrimp growth rate was statistically higher (P < 0.05) in the 350 and 400 g kg^?1 CP diets than in the 300 g kg^?1 CP diet treatment. There were no differences in the nutritional condition of shrimp between treatments, as determined by moisture and protein content, and lipid content of the digestive gland. Using ¹⁵N‐nitrogen isotope tracers, it was determined that shrimp were consuming natural biota, although these were unlikely to have contributed substantially to their nutrition. Total nitrogen (TN) concentrations in the water column increased over the eight week experiment and were statistically different (P < 0.001) between treatments (3.60, 5.17 and 6.45 mg L^?1 in the 300, 350 and 400 g kg^?1 CP treatments, respectively). Concentrations of dissolved organic nitrogen (DON) were also statistically different between treatments and made up 35–40% of the TN in the water column. Concentrations of total ammoniacal nitrogen (TAN) and oxides of nitrogen, and fluorescence were not statistically different between treatments but there was a trend of higher concentrations in treatments with higher protein levels. There was no difference in sediment nutrients between treatments. This study has shown that there is scope to reduce the protein content of P. monodon diets but only by 5–10%. However, further validation of these results in commercial ponds is needed. Reducing the feed protein content may result in cost savings and also has the advantage of improving water quality and reducing nitrogen discharge.     

Preliminary Pond Production of the Red Claw Crayfish,Cherax Quadricarinatus,in the Central United States

The Australian red claw crayfish, Cherax quadricarinatus, has recently attracted attention as a potential candidate for aquaculture in the United States. This paper reports the first experimental yield trials of the red claw crayfish in the central United States. Two earthen ponds (0.30 and 0.31 ha) were stocked with juvenile red claw crayfish at either 3.5 or 7.0 crayfish/m². Crayfish were fed a diet of pelletized shrimp ration supplemented with corn silage. When stocked at 3.5/m₂, red claw crayfish grew from an average weight of 3.0 g to 27.0 g in 97 days; average survival was 79.6%; net yield was 653 kg/ha; and feed conversion was 1.4. When stocked at 7.0/m² red claw crayfish grew from an average weight of 4.1 g to 19.7 g in 99 days; average survival was 70.0%; net yield was 678.9 kg/ha; and feed conversion was 1.8. During the yield trial, temperatures were optimal for growth (25 to 33°C) 60% of the time. These findings are sufficiently encouraging to warrant further trials in locations with a longer growing season, in order to evaluate more fully the potential of the red claw crayfish as a candidate for aquaculture in the United States.     

Management Strategies for Production of the Atlantic White Shrimp Penaeus setiferus as Bait Shrimp in Outdoor Ponds

Abstract The geographic distribution of the Atlantic white shrimp Penaeus setiferus is in coastal waters from New York to Florida and around the Gulf of Mexico. Beside its value to commercial fisheries, this shrimp is sold as bait for recreational fishing. Previous data suggest that demand for live bait shrimp cannot be satisfied by commercial fleets. A 120-d trial was designed to study production of bait size P. setiferus at high densities in eight small outdoor ponds in south Texas. A 2^4–1 fractional factorial design was applied to study the effects of postlarval (PL) density (350 and 700 shrimp/m²), feed type (A and B), and water circulation methods (with and without airlift pumps or center pond dividers) on shrimp growth, survival and yield. No significant differences in survivals or yields were found between treatments (P = 0.2). Feed type ( P = 0.011), airlift pumps ( P = 0.021), and center dividers ( P = 0.026), had significant impacts on shrimp growth rates. Density effect on growth was not statistically significant ( P = 0.055). This study demonstrated that 6-d-old postlarvae can be stocked at 700 per square meter and reached a bait size (6.2 g) in 94 d with a 73.6% survival and a yield equivalent to 31,300 kg/ha when offered a commercial shrimp feed. A preliminary economic analysis based on this data suggests that operating a bait shrimp farm in Texas with two crops/yr will show profitability within 7 to 12 yr with an internal rate of return of 6.5 and 17.6%, respectively.     

Passive immunity in tiger shrimp (Penaeus monodon) fed with monoclonal antibody to white spot syndrome virus

A study was conducted on the stability of monoclonal antibody (MAb) in the hepatopancreas and hemolymph of Penaeus monodon and its effect on protection against white spot syndrome virus (WSSV) upon challenge. MAb C-5 raised against WSSV was purified and coated onto a commercial shrimp feed at dosages of 5, 10 and 15 mg/kg feed. The feed was fed to P. monodon and stability of the MAb in hepatopancreas and hemolymph was determined by immunodot and Western blot. Immunodot results indicated the presence of MAb for 2 h post-feeding in hepatopancreas and hemolymph which was dose-dependent. MAb was also detected in hemolymph by Western blot up to 1 h post-feeding. Shrimp fed with MAb were challenged with WSSV by oral and injection methods. In shrimp fed with 15 mg antibody/kg feed (0.45 μg MAb/g shrimp/day) WSSV infection significantly delayed both in oral and injection challenges with a survival of 65 and 70 % (p < 0.05), respectively, during 15 days post-challenge. MAb was stable in shrimp for passive immunization against WSSV and could be a potential tool for prophylaxis against the virus.     

MALAYSIAN PRAWN CULTURE IN BRACKISH WATER PONDS IN LOUISIANA

Beginning on May 13, 1980, prawns were cultured at the Rockefeller Wildlife Refuge for 140 days from postlarvae and fed. Production in ponds receiving Ralston Purina Experimental Marine Ration #25 averaged 408 kg/ha, 619 kg/ha and 510 kg/ha for the respective replicated stocking densities of 2.5/m², 4.9/m² and 7.4/m². Average feed conversion factors were 1.0, 1.0 and 1.5. Average prawn weights at harvest decreased with increased stocking density and were 21 g, 17 g and 12 g, respectively. Production per pond ranged from 390 kg/ha to 832 kg/ha. An average of 77% of prawns stocked at 2.5/m² exceeded 115 mm TL whereas the stocking densities of 4.9/m² and 7.4/m² yielded only 32% and 31% over 115 mm. Extra postlarvae remaining after the stocking requirements for the feeding study were met permitting additional tests. Stocking rates selected for these additional studies were 1.2/m², 2.5/m² and 3.7/m². Prawns in these ponds received no supplemental feed and yielded harvests of 124 kg/ha, 224 kg/ha and 292 kg/ha, respectively. These treatments, the first two of which were not replicated, resulted in production similar to that of an earlier study of prawn production on natural forage in brackish ponds at this facility. Average prawn sizes at harvest were 18 g, 15 g and 12 g, and were inversely related to stocking densities.     

The Culture of Penaeus semisulcatus in Israel

Growth performance data on Penaeus semisulcatus under semi-intensive pond culture conditions were collected in Israel between 1985 and 1987. In 1985, shrimp growth, from PL to 21.5 g, was accomplished in separate nursery and grow-out phases. Pond production during the grow-out phase was 3,000 and 3,943 kg/ha, and mean weight was 21.5 g. Shipments to Europe revealed a need to produce larger shrimp to maximize revenues. Any increase in individual shrimp weight at harvest would require new management practices. Juvenile shrimp (3.4 to 6.3 g) were held during the winter of 1986 in open ponds and restocked in grow-out ponds in the spring of 1987. Shrimp survival during overwintering was 12 and 15%. A maximum mean shrimp weight of 25.6 g and a maximum pond production of 7,451 kg/ha were obtained in 1987 using this strategy. It is possible that comparable pond production results and shrimp weight, but with higher overall shrimp survival, could be obtained by headstarting shrimp in greenhouses. Two major problems that need to be solved before commercial shrimp culture can succeed in Israel are the formulation of a locally produced feed and the out-of-season induced maturation and spawning of P. scmisulcarus .     

Fungus,Aspergillus niger,fermented groundnut oil cake as a fishmeal alternative in the diet of Penaeus vannamei

Commercial de‐fatted groundnut oil cake (GNC) fermented with the fungus Aspergillus niger was evaluated as a fishmeal alternative in the diet of Penaeus vannamei. A 45‐day growth trail was performed using nine iso‐nitrogenous and iso‐lipidic diets. Untreated/fermented GNC was included at the rate of 0 (control), 25, 50, 75 and 100 g/kg by replacing fishmeal (w/w). Each diet was randomly assigned to triplicate group of 20 shrimps (initial weight of 3.09 ± 0.03 g). Results revealed that shrimp fed with diets having untreated GNC up to 50 g/kg has no significant difference in growth, whereas the inclusion level was enhanced to 100 g/kg with fermented GNC with no deleterious effect. The negative linear trend was found for SGR with increasing the inclusion of both untreated and fermented GNC. The feed and protein efficiency measures, viz. feed conversion ratio, protein efficiency ratio and apparent protein utilization, were better in shrimps fed with diets having fermented GNC than those fed the respective level of untreated GNC. The broken‐line analysis indicated that the inclusion of 72.5 g/kg fermented GNC showed the best FCR. No significant difference was observed in survival (86.67%–96.67%) between the dietary treatments. There was a significant difference in ether extract of shrimp between the treatments, whereas other parameters were not affected. Haemolymph indices showed a significant difference in total protein, glucose, cholesterol and triglycerides between control and test diets. The results conclude fermented GNC, which can be better than untreated one in the diet of shrimp.     

Effects of Density Reduction and Supplemental Feeding on Stunted Crayfish Procambarus clarkii Populations in Earthen Ponds1

Density reduction, supplemental feeding, and a combination of two treatments were evaluated as means to alleviate stunting of red swamp crayfish Procambarus clarkii in earthen ponds. Mean total yield of crayfish in low density control ponds averaged 1,218 kg/ha and was 1.5 to 2 times higher (P≤ 0.05) than either the high density control or treatment ponds. Mean individual harvest weight of crayfish averaged 15.1 g and did not differ among treatments. Mean total yield of crayfish in ponds receiving supplemental feed was 32% higher than non-fed ponds (P≤ 0.05). Mean total yield and size of crayfish at harvest from reduced and non-reduced treatments did not differ. Density reduction and supplemental feeding implemented in early April did not increase individual crayfish weight to the commercially desirable size of 20 g.     

Resource Use Assessment of Shrimp,Litopenaeus vannamei and Penaeus monodon,Production in Thailand and Vietnam

Resource use was investigated at 34 Litopenaeus vannamei and five Penaeus monodon farms in Thailand and 30 L. vannamei and 24 P. monodon farms in Vietnam. Farms varied in water surface areas for production, reservoirs, canals, and settling basins; in pond size and depth; and in water management, stocking density, feeding rate, amendment input, aeration rate, crop duration, and crops per year. Production of L. vannamei averaged 17.3 and 10.9 m.t./ha/yr, and feed conversion ratio averaged 1.49 and 1.33 in Thailand and Vietnam, respectively. On average, production of 1 m.t. of L. vannamei required 0.58 ha land, 5,400 m³ water, 60 GJ energy, and 1218 kg wildfish in Thailand and 1.76 ha land, 15,100 m³ water, 33.7 GJ energy, and 1264 kg wildfish in Vietnam. Resource use per metric ton of shrimp declined with greater production intensity. In Thailand, P. monodon was produced at 0.2–0.4 m.t./ha/yr, with no inputs but water and postlarvae. In Vietnam, P. monodon production averaged 3.60 m.t./ha/yr. Production of 1 m.t. of P. monodon required 0.80 ha land, 36,000 m³ water, 47.8 GJ energy, and 1180 kg wildfish, and resource use per ton production declined with increasing production intensity.     

Pond production of Pacific white shrimp,Litopenaeus vannamei,fed grain distillers dried yeast

The objective of this study was to demonstrate the feasibility of four diets formulated to contain increasing levels (0, 50, 100 and 150 g kg^?1 of diet) of grain distillers dried yeast (GDDY) in production diets for Litopenaeus vannamei, reared in outdoor tanks or production ponds. The production pond trial was carried out in 16, 0.1‐ha ponds using four replicates per diet. Juvenile shrimp (38.1 ± 4.26 mg, initial weight) were stocked at 30 shrimp m^?2 for a 16‐week period. The same four diets and a commercial reference diet were offered to shrimp maintained in outdoor tanks over a 12‐week period. A total of 20 tanks were stocked with juvenile shrimp (3.05 ± 0.22 g, initial weight) obtained from production ponds at a density of 30 shrimp per tank (40 shrimp m^?2). At the conclusion of these trials, mean final weight ranged from 19.77 to 23.05 g, yield ranged between 4760 and 5606 kg ha^?1, survival ranged from 69.6% to 89.4%, and feed conversion ratio (FCR) was between 1.02 and 1.23. Shrimp reared in the outdoor tanks confirmed the results of the pond trial. Mean final weight ranged between 18.12 and 18.97 g, survival ranged from 93.3% to 98.3%, and FCR was between 1.25 and 1.29. In both trials, there were no significant differences regarding mean final weight, FCR and survival among dietary treatments. Based on this study, GDDY up to 150 g kg^?1 of diet can be used in L. vannamei commercial feed formulation.