Resources

Language
English

Date Published
October 30, 2002

Author
United States Soybean Export Council
Description

Aquaculture feed ingredients tend to be mostly by-products of processing or milling industries, but also consist of natural products. In everyday formulation of diets, these ingredients are included and substitutions made within mixtures in accordance with market price, local availability and composition. Basically, the concept is to use available ingredients in the most economical way to provide the essential nutrient content and balance of the final diet. Different proportions of less expensive ingredients can often be combined to achieve the nutrient balance of more expensive ones. However, it is also necessary to consider factors such as the quality, palatability and functional properties of ingredients as well as the possible content of anti-nutritional components that are known to affect the growth and health of fish.

The purpose of this paper is to briefly review published information about five of the most commonly available feed ingredients of plant origin, and to provide guidelines for quality standards and usage of these ingredients in aquaculture feeds.

Language
English

Date Published
October 30, 2002

Author
Plant Protein Ingredients for Aquaculture Feeds: Use Considerations & Quality Standards
Description

A feeding trial was conducted in Nanjing, Jiangsu Province, to demonstrate fingerling to market growth performance of pacu Piractus branchypomum using the ASA 80:20 pond production model and the ASA all-plant protein, soymeal-based growout feed. Fish were stocked in three, 4-mu ponds at a density of 900 pacu and 100 silver carp per mu. Pacu grew from 40 g to an average weight of 497 g per fish in 80 days of feeding. Gross production averaged 443 kg/mu for pacu and 102 kg/mu for silver carp. Average survival rates for pacu and silver carp were 99% and 98%, respectively. The soy-based feed yielded a FCR with pacu of 1.24:1. Average net economic return was RMB 715 permu. Average return on investment (ROI) was 31.2%. This compared to an FCR of 2.84:1 with the farm’s traditional feed, which yielded an ROI of –8.6%. Pacu demonstrated excellent growth performance and feed conversion efficiency with the ASA soymeal-based feed and 80:20 production technology in this trial. Pacu produced in the trial were uniform in size with good body color and conformation.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

Historical inclusion rates of fish meal in aquaculture feeds are unsustainable because of limited supply and increasing costs. Alternative plant protein sources must be identified. The goal of this project was to systematically examine the antinutritional factors in soybean meal and their effects on rainbow trout and Atlantic salmon. A Managed Research Program, funded by the United Soybean Board, Indiana Soybean Alliance, Illinois Soybean Association, Iowa Soybean Association and Ohio Soybean Council, was established that included participants from seven US institutions. The University of Idaho, in collaboration with the US Fish and Wildlife Service Fish Technology Center, and Michigan State University evaluated the effects of trypsin inhibitors (TI) in both species and the effects of extrusion conditions on TI activity. Purdue University evaluated the effects of soybean lectins in diets fed to both species and the interactive effects of feeding lectins, trypsin inhibitors and oligosaccharides to rainbow trout. The Ohio State University examined the effects of soy saponins on rainbow trout. The Universities of Maine and Wisconsin evaluated the effects of soybean isoflavones, with emphasis on genistein, on rainbow trout and Atlantic salmon. The University of Maine also conducted taste tests of trout and salmon to characterize flavors of salmonids fed soy-based diets. Kentucky State University conducted an economic analysis on feeding high soybean diets to salmonids in order to develop least cost diet formulations utilizing the highest possible levels of soybean meal. The approach undertaken was a relatively complete series of studies that described the effects of soybean antinutritional factors on rainbow trout and Atlantic salmon.

The key findings of the Soy-in-Aquaculture Program indicated which particular soybean antinutritional factors have been limiting the amount of soybean meal fed to salmonids. Lectins and trypsin inhibitors were both identified as exerting antinutritional effects on rainbow trout and Atlantic salmon when included in the diet at levels corresponding to a 35-40% soybean meal diet. In a study with rainbow trout, feeding trypsin inhibitors resulted in a 12% reduction in growth and feeding lectins resulted in a 14% reduction in growth. Saponins did not exert antinutritional effects when fed to rainbow trout, and were shown to have a potential benefit by enhancing the immune response. There were no observed negative effects (growth or reproduction) as a result of feeding soy genistein to rainbow trout; however, when fed to Atlantic salmon, smoltification was inhibited. Fillets from fish fed soybean meal were lighter in color, but there were no detectable differences in flavor when sampled by an untrained panel. Additional findings of the Soy-in-Aquaculture Program indicated that a higher extruder barrel temperature and shorter retention time may be the optimum settings when extruding high-soybean meal diets for salmonids. Finally, using least-cost modeling, soy inclusion rates were calculated to be 15 and 25% in Atlantic salmon and rainbow trout diets, respectively. The results of these studies identified specific antinutritional factors limiting the amount of soy ingredients used in salmonid diets. These results show farmers and processors which antinutritional factors need to be reduced in soy ingredients.

Language
English

Date Published
October 30, 2002

Author
Steven D. Hart (Purdue University), Frederic T. Barrows (Agricultural Research Service, Hagerman Fish Culture Experiment Station), Konrad Dabrowski (Ohio State University), Siddhartha Dasgupta (Kentucky State University), Donald L. Garling (Michigan State)
Description

Aquacultural production of trout and salmon, collectively referred to as salmonids, is one of the largest global aquaculture industries and currently uses a disproportionately high amount of fish meal in dietary formulations. Sustainable production and growth in salmonid culture demands identification of alternative high-protein feed ingredients. The chemical composition of soy protein concentrate (SPC) suggests it has potential has an ingredient in diets fed to salmonids. There have been over 30 published studies of SPC use in diets for rainbow trout and Atlantic salmon. The data indicate small trout and salmon are more sensitive to SPC inclusion in diets than larger fish. SPC can provide up to 50% of the dietary crude protein in diets for small fish. Fish meal can be completely replaced in diets for larger fish. Results from digestibility studies indicate high nutrient availability from SPC. Methionine supplementation appears necessary for salmonids and taurine supplementation was recently identified as beneficial in SPC-based diets for trout. The form of phosphorus in SPC remains problematic, but incorporation of phytase or pretreatment of SPC with phytase improved phosphorus availability. Sensory characteristics of salmonid fillets fed SPC have been lighter in color than those from fish fed fish meal, but texture and flavor have not been adversely impacted. Several dietary formulations are available that have been tested in the target species. Ingredient cost hampered use of SPC in the 1990’s and remains an issue in the 21st century. However, given the escalating price of fish meal and demand for that commodity, use of SPC in salmonid diets appears promising.

Language
English

Date Published
October 30, 2002

Author
Steven D. Hart and Paul B. Brown
Description

A feeding trial was conducted near Haikou, Hainan Province, to demonstrate fingerling to market growth performance of pangasius catfish using the ASA 80:20 pond production model and the ASA soymeal-based, all-plant protein growout feed. Fish were stocked in two, 2.5-mu ponds and one 2.0-mu pond at a density of 735 catfish and 100 silver carp per mu. Pangasius catfish grew from 150 g to an average weight of 659 g per fish in 74 days of feeding. Gross production of pangasius averaged 485 kg/mu. Survival of pangasius was 100%. FCR for pangasius with the soy-based feed averaged 1.17:1. Average net economic return was RMB 5,013 per mu at a market price of RMB 25/kg for pangasius catfish. Average return on investment (ROI) was 71%. Pangasius catfish demonstrated excellent growth performance and feed conversion efficiency with the ASA soymeal-based feed and 80:20 production technology in this trial. Pangasius produced in the trial were uniform in size with good body color and conformation.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

A feeding trial was conducted in Shenyang, Liaoning Province, to demonstrate fingerling to market growth performance of common carp using the ASA 80:20 pond production model and the ASA all-plant protein, soymeal-based growout feed. Fish were stocked in three, 2.4-mu ponds at a density of 700 common carp and 100 silver carp per mu. Common carp grew from 80 g to an average weight of 668 g per fish in 99 days of feeding. Gross production averaged 466 kg/mu for common carp and 79 kg/mu for silver carp. Average survival rates for common carp and silver carp were 99.6% and 100%, respectively. Common carp FCR with the soymeal-based feeds averaged 1.46:1. Average net economic return was RMB 371 per mu, for an average return on investment (ROI) of 15.4%. Results of the feeding demonstration showed that common carp exhibited good growth performance and FCR with the ASA soymeal-based feed and 80:20 production technology. Common carp reached the target market size in just 99 days and had good quality and market acceptance. The use of extruded, floating feed significantly reduced labor costs, lowered fish FCR, improved water quality, and allowed production of healthy and disease-free fish without the use of drugs or chemicals.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

A feeding trial was conducted in Hefei, Anhui Province, to demonstrate fingerling to market growth performance of grass carp using the ASA 80:20 pond production model and the ASA all-plant protein, 66% soy-product grass carp feed. Fish were stocked in three, 5-mu ponds at a density of 760 grass carp and 100 silver carp per mu. Grass carp grew from 49 g to an average weight of 751 g per fish in 190 days of feeding. Gross production averaged 544 kg/mu for grass carp and 115 kg/mu for silver carp. Average survival rates for grass carp and silver carp were 95.4% and 99%, respectively. Grass carp FCR with the 66% soy product feed averaged 1.36:1. Average net economic return was RMB 720 per mu, for an average return on investment (ROI) of 27%. Production and economic averages are for two ponds only, as fish were poached from one pond just before harvest. Results of the feeding demonstration showed that grass carp exhibited excellent feeding behavior, growth performance and FCR with the ASA 66% soy-product feed and 80:20 production technology. Grass carp reached the target market size and had good body shape and conformation, with little size variation. Grass carp were reported to have better taste than fish cultured on the farm using traditional techniques. Water quality was also reported to be much better than normal, and no disease problems occurred. The use of extruded, floating feed significantly reduced labor costs, lowered fish
FCR and improved water quality, and allowed production of healthy fish without the use of drugs or chemicals.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

A feeding trial was conducted in Changzhou, Jiangsu Province, to demonstrate fry to fingerling performance of wuchang bream using the ASA 80:20 pond production model and ASA soymeal-based fry and fingerling feeds. Fish were stocked in three, 5.0-mu ponds at a density of 9,000 wuchang bream and 1,000 silver carp per mu. Wuchang bream grew from 0.1 g to an average weight of 50.8 g per fish in 137 days of feeding. Gross production averaged 306 kg/mu for wuchang bream and 62 kg/mu for silver carp. Average survival rates for wuchang bream and silver carp were 67% and 43%, respectively. Low survival rates were the result of under-stocking. Wuchang bream FCR with the soymeal-based feeds averaged 0.93:1. Average net economic return was RMB 652 per mu, for an average return on investment (ROI) of 33.6%. Results of the feeding demonstration showed that wuchang bream exhibited good growth, feeding behavior and FCR with the ASA soymeal-based feeds and 80:20 production technology during the fry to fingerling phase. In addition, the soy-based extruded feeds yielded good water quality, lower labor costs, and allowed production of healthy and disease-free fish without the use of drugs or chemicals.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

Growth performance of red tilapia was demonstrated from fingerling to market stages using the ASALVHD cage technology and an all-plant protein, soy-based feed. Red tilapia in three replicate cages of size 1.0-m3 were fed to satiation twice daily with the ASA 32/6 soybean meal-based feed in extruded, floating pellet form. Tilapia grew from 52 g to 577 in 150 days, with an average FCR of 1.34:1. Fish survival averaged 98.3%. Fish production averaged 225.8 kg/m3. Net economic return averaged RMB 712 per m3, at an average market price of RMB 10/kg for red tilapia. Return to investment averaged 46% for the three trial cages.

Production of 225 kg/m3 demonstrated the effectiveness of the ASA LVHD technology and soy-based feed. Compared to traditional cages, the LVHD cages yielded higher production, were easier to manage, and had lower labor costs. The ASA soy-based feed yielded lower FCR, better fish health, higher economic return and less environmental contamination than was previously obtained by the cooperator with traditional sinking feeds. In addition, no drugs or chemicals were required in the trial, which yielded high quality “green” fish without contamination.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

A feeding trial was conducted in Taixing, Jiangsu Province, to demonstrate fingerling to market growth performance of GIFT tilapia using the ASA 80:20 pond production model and the ASA all- plant protein, soymeal-based growout feed. Fish were stocked in three, 5-mu ponds at a density of 1,000 tilapia and 100 silver carp per mu. Tilapia grew from 28 g to an average weight of 525 g per fish in 131 days of feeding. Gross production averaged 509 kg/mu for tilapia and 75 kg/mu for silver carp. Average survival rates for tilapia and silver carp were 97.5% and 98%, respectively. Average FCR for tilapia with the soy-based feed was 1.19:1. Feed cost per kilogram of fish weight gain was RMB 3.63. Net economic return was RMB 1,200 per mu. Average return on investment (ROI) was 36.4%. Tilapia demonstrated excellent growth performance, feed conversion efficiency and economic return with the ASA extruded, soymeal-based feed and 80:20 production technology in this trial.

Language
English

Date Published
October 30, 2002

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

Weaning of 74-g Japanese sea bass (Lateolabrax japonicus) from trash fish to extruded feed, followed by growout to market size on extruded feed, was demonstrated in a cage feeding trial at Longmen Town, Qingzhou City, Guangxi Province, China. Sea bass that had only been fed with trash fish were stocked in three, 6.4-m3 cages at a density of 156 fish per m3 and weaned from trash fish to extruded feed over a period of one week. After weaning to extruded feed, the sea bass were fed to satiation twice daily with a 43/12 extruded, floating marine fish feed formulated by ASA. Dehulled soybean meal was used as a partial replacement for fishmeal in the 43/12 feed. Sea bass grew from 74 g to 505 g in 144 days on the ASA feed, with an average FCR of 1.31:1. Average fish carrying capacity at harvest was 72 kg/m3 of cage. The average fish survival rate was 91.1%. Net economic return and return on investment for the trial were RMB 714/m3 and 82.2%, respectively. Sea bass weaned from trash fish to extruded feed without difficulty and exhibited good production performance on the extruded feed following weaning. Feed conversion efficiency with the ASA 43/12 feed, which contained 35% dehulled soybean meal by weight, was significantly lower than that obtained with trash fish. Feed cost per kilogram of fish growth with the ASA extruded feed was RMB 6.29, which was substantially below the cost of producing sea bass with trash fish. Sea bass demonstrated a high degree of tolerance for low salinity water conditions that prevailed at the Longmen site throughout the duration of the feeding trial.

Language
English

Date Published
October 31, 2001

Author
ichael C. Cremer, Zhang Jian and Hsiang Pin Lan
Description

Weaning of 161-g red drum (Sciaenops ocellata) from trash fish to extruded feed, followed by growout to market size on extruded feed, was demonstrated in a cage feeding trial at the He Sheng Fa Cage Fish Farm in Ma Nan Bay, Xiamen, Fujian Province, China. Red drum that had only been fed with trash fish were stocked in three, 8.0-m3 cages at a density of 100 fish per m3 and weaned from trash fish to extruded feed over a period of one week. After weaning to extruded feed, red drum were fed to satiation twice daily with a 43/12 extruded, floating marine fish feed formulated by ASA using dehulled soybean meal as partial replacement for fishmeal. Red drum grew from 161 g to 834 g in 155 days on the ASA feed, with an average FCR of 1.99:1. Average fish carrying capacity at harvest was 74.5 kg/m3 of cage. The average fish survival rate was 89.5%. Net economic return and return on investment for the trial were RMB 360/m3 and 43.3%, respectively. The trial demonstrated that sub-market size red drum could be weaned from trash fish to extruded feed without difficulty. However, chronic poor water quality conditions at the trial site resulted in feed conversion efficiency with the 43/12 extruded feed that was substantially below standard. FCR with the extruded feed was still significantly better than that obtained in the area with trash fish. Feed cost per kilogram of fish growth with the ASA extruded feed was RMB 9.55, which was substantially below the cost of producing red drum with trash fish. Red drum production performance was confounded by chronically poor water quality at the test site. Dissolved oxygen level was generally below 60% saturation throughout the production season. Results of the trial indicate that Ma Nan Bay is a high- risk culture site that will likely continue to experience chronic water quality problems and periodic catastrophic fish kills related to poor water quality. Use of highly polluting trash fish and too many fish cages are the primary problems that constrain fish production. The number of fish cages needs to be drastically reduced in Ma Nan Bay and the use of trash fish prohibited to permit recovery of the ecosystem and allow sustainable fish culture in the future.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Hsiang Pin Lan
Description

Weaning of sub-market size snapper (Lutjanus sp.), locally known as red-purple snapper, from trash fish to extruded feed, followed by growout to market size on extruded feed, was demonstrated in an ASA cage trial conducted in Dong Shan Bay, Long Gang, Shenzhen. Snapper that had previously been fed with trash fish were stocked in three, 4.5-m3 cages at a density of 150 fish per m3 and weaned from trash fish to extruded feed over a period of one week. After weaning to extruded feed, snapper were fed to satiation twice daily with a 43/12 extruded, floating feed. Snapper grew from 233 g to 522 g in 118 days on the ASA feed, with an average FCR of 1.96:1. Average fish carrying capacity at harvest was 55.8 kg/m3 of cage. The average snapper survival rate was 71.3%. The approximately 29% mortality rate was attributed to fish injuries sustained during a series of typhoons in June and July. Net economic return and return on investment for the trial were RMB 727/m3 and 48.5%, respectively. Results of the trial demonstrated that Lutjanus sp. snapper could be successfully weaned from trash fish to extruded feed at a large size. Cage production of snapper was demonstrated to be technically and economically feasible with the ASA extruded feed under proper environmental conditions. The ASA 43/12 marine fish feed is formulated with 35% dehulled soybean as a partial replacement for fishmeal. The dehulled soybean meal inclusion rate is 35% by
weight. Despite a significant fish mortality rate, snapper yielded a 48.5% return to investment in this trial.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Hsiang Pin Lan
Description

Growth performance of wuchang bream was compared from fingerling to market stages in an ASA 80:20 pond technology trial using two ASA soy-based aquafeeds. This was the second year of a two-year wuchang bream evaluation trial conducted at the Tai Xing Fish Stock Farm in Jiangsu Province. Wuchang in six replicate trial ponds were fed to satiation twice daily with the ASA feeds. Wuchang in three of the ponds were fed with the standard ASA 32/6 carp growout feed. Wuchang in the other three ponds were fed with the ASA 32/3 grass carp feed. Both feeds were fed in extruded, floating pellet form. Wuchang fed the 32/6 feed grew from 36 g to 329 g in 188 days of feeding, with an average FCR of 1.78:1. Fish fed the 32/3 grass carp feed grew from 36 g to 313 g in 188 days of feeding, with an average FCR of 1.83:1. Wuchang survival averaged 93.1% and 95.5%, respectively, for fish fed the 32/6 and 32/3 feeds. Gross production averaged 245 kg per mu for wuchang bream and 67 kg/mu for silver carp in the three ponds receiving the 32/6 feed. In ponds receiving the 32/3 feed, gross production was 239 kg per mu for wuchang bream and 90 kg per mu for silver carp. Net economic return averaged RMB 328 per mu and RMB 655 per mu for fish fed the 32/6 and 32/3 feeds, respectively. Return on investment was significantly higher for fish fed the 32/3 feed because of the lower cost of the feed.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

Grass carp growth performance with the ASA 32/3 grass carp feed was demonstrated in three ASA 80:20 pond technology trials in 2001. The ASA 32/3 feed is a 32% crude protein, 3% fat and 8% fiber feed, formulated with standard soybean meal as the primary protein source and soy hulls as the primary fiber source. Trial sites for 2001 were in Harbin in Heilongjiang Province, Beijing, and Meixian in Guangdong Province. In all three trials, grass carp were fed to satiation with the ASA 32/3 feed in extruded, floating pellet form. Grass carp in the Harbin trial grew from 70 g to 713 g in 140 days with an estimated FCR of 1.59:1. Fish survival in the Harbin trial was 84%, and production averaged 360 kg per mu for grass carp and 124 kg/mu for silver carp. In the Beijing trial, grass carp grew from 125 g to 811 g in 181 days with an FCR of 1.41:1. Fish survival was 93% and production averaged 493 kg/mu for grass carp and 110 kg/mu for silver carp. In the Meixian trial, grass carp grew from 84 g to 1,053 g in 138 days with an FCR of 1.19:1. Fish survival was 96% and average production was 607 kg/mu of grass carp and 52 kg/mu of silver carp. Return to investment for the three trials ranged from 9.6% in Beijing to 47.4% in Meixian. The results of the three 2001 trials confirm results obtained in a 2000 trial in Beijing with the newly introduced ASA 32/3 grass carp feed. In the 2000 trial, grass carp grew from 100 g to 815 g in 174 days, with an FCR of 1.27:1 and average production of 502 kg/mu of grass carp and 139 kg/mu of silver carp. Collectively, the results of the four ASA grass carp trials conducted in 2000 and 2001 indicate that the ASA 32/3 grass carp feed yields good grass carp growth performance, low FCR, good fish body conformation, and good market acceptance. With high inclusion rates of standard (44% crude protein) soybean meal and soy hulls, the all-plant protein ASA 32/3 grass carp feed is a low-cost feed that has excellent application potential for China grass carp producers.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua
Description

Pompano (Trachinotus ovatus) growth performance in coastal cages was evaluated from fingerling to sub-market size using the ASA LVHD cage production model and ASA extruded, marine fish feeds. The cage trial was conducted at Ling Shui, Hainan, China. Pompano were stocked in three, 8.0-m3 cages at a density of 1,000 fish per cage. Pompano were fed to satiation daily with a 47% crude protein and 15% crude fat feed (47/15) to fish size 50 g, and with a 43% crude protein and 12% crude fat feed (43/12) from fish size >50 g. The 43/12 feed was formulated with 35% soybean meal. Both feeds were fed in extruded, floating pellet form. Fish in all trial cages were fed to satiation, three times daily for the first month, and twice daily thereafter. Pompano grew from 7 g to 349 g in 136 days. Average FCR with the combination of 47/15 and 43/12 feeds was 2.1:1. Average fish survival was 92.5%. Net economic return and return on investment were RMB 5,511/cage (RMB 689/m3) and 90.1%, respectively. Results of the trial indicate that pompano perform well on extruded feed and yield high economic gain. The trial pompano fed extruded feed were reported to have grown faster than pompano fed trash fish, and with a significantly lower feed cost. Feed cost with the ASA extruded feeds was RMB 10.08 per kilogram of fish growth. Cost of trash fish was reported to be in excess of RMB 20 per kilogram of fish growth. Other reported benefits of producing pompano with
extruded feed were simplified production management, reduced water pollution, and production of pompano with a better flavor than those cultured with trash fish.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Hsiang Pin Lan
Description

Red drum (Sciaenops ocellata) fingerling production in coastal cages was demonstrated using a two-stage cage production regime and extruded aquafeeds in an ASA feeding trial conducted near Ningbo, Zhejiang Province, China. In the first stage of the production regime, red drum were stocked in six, 2.25-m3 cages at a density of 2,500 fish per cage and fed to satiation daily for 30 days with a 47% crude protein and 15% crude fat (47/15 feed) extruded, marine fingerling feed. After 30 days, the fish were transferred to three, 8-m3 cages and stocked at a density of 200 fish per m3 for the second stage of the production regime. Fish in the three 8-m3 cages were fed the 47/15 feed to size 25 g, at which point the fish were weaned to a lower cost 43/12 marine growout feed. Both feeds were fed in extruded, floating pellet form. The 43/12 feed is formulated with 35% soybean meal as a partial replacement for fishmeal. Red drum grew from 0.5g to 5.6 g in the 30-day, stage one component of the trial. Average FCR with the 47/15 feed during stage one in the 2.25-m3 cages was 1.04:1. Average fish survival was 77.7%. In the second stage, red drum grew from 5.6 g to 92.5 g in 88 days on a combination of 47/15 and 43/12 feeds. Average FCR for the combination of 47/15 and 43/12 feeds in stage two was 1.31:1. Fish survival averaged 51.3% in the stage two component of the trial. Results of the trial indicate that red drum perform well during the first production stage in 2.25-m3 cages, yielding good survival and excellent growth and feed conversion with the 47/15 extruded feed. Growth and FCR continued to be good in the second production stage in 8.0-m3 cages, but survival dropped significantly. Poor survival was believed to result from a combination of poor water quality and parasitic infestation. The two-stage production regime and combination-feeding regime with extruded 47/15 and 43/12 feeds was demonstrated to be a good strategy for producing red drum fingerlings. However, producers should be aware that red drum are sensitive to poor environmental conditions and should be cultured only in areas with good water quality.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Hsiang Pin Lan
Description

Yellow croaker (Pseudosciaena crocea) growth performance in coastal cages was evaluated during the fingerling production cycle with two feeds in a two-part ASA feeding trial at Ningbo, Zhejiang Province, China. Yellow croaker were stocked in six, 2.25-m3 cages at a density of 2,500 fish per cage and fed to satiation daily for 30 days with a 47% crude protein and 15% crude fat (47/15 feed) extruded feed in the first stage of the trial. After 30 days, fish were transferred to six, 8-m3 cages and stocked at a density of 200 fish per m3 for the second stage of the trial. Fish in three of the 8-m3 cages were continued on the 47/15 feed, while fish in three other replicate cages were fed the ASA marine fish growout feed formulated to contain 43% crude protein and 12% crude fat (43/12 feed). Both feeds were fed in extruded, floating pellet form. Fish in all six cages were fed to satiation, three times daily for the first month, and twice daily thereafter. Yellow croaker grew from 2.2 g to 5.7 g in the 30-day, stage one component of the trial. Average FCR with the 47/15 feed during stage one was 1.20:1. Average fish survival was 99.6%. In the second stage, yellow croaker fed the 47/15 feed grew from 5.8 g to 42.4 g in 93 days, while yellow croaker fed the 43/12 feed grew from 5.8 g to 42.8g. Survival averaged 84.7% for fish fed the 47/15 feed, and 85.6% for fish fed the 43/12 feed. FCR averaged 1.66:1 for fish fed the 47/15 feed, and 1.63:1 for fish fed the 43/12 feed. There was no significant difference (P>0.05) in fish growth, survival or FCR for the two feed treatments. Results of the trial indicate that yellow croaker perform well on the 47/15 feed during the first 30 days of the fingerling production cycle, exhibiting excellent growth performance, survival and FCR, but that production performance is not enhanced by feeding the 47/15 feed beyond 30 days. Fish growth performance, survival and FCR were equivalent with the 47/15 and 43/12 feeds during the 93-day, stage-two trial period. At a 23% cost premium for the 47/15 feed, no benefits were demonstrated that would justify use of the higher cost feed after fish attain a size of approximately 5 g. ASA recommends use of the ASA 47/15 feed for culturing yellow croaker from 2 g to 5 g in size, followed by feeding with the ASA 43/12 feed from fish size 5 g to market size.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Hsiang Pin Lan
Description

A feeding trial was conducted in Harbin, Heilongjiang Province, located at 46o north latitude, to demonstrate fry to fingerling growth performance of mirror carp using the ASA 80:20 pond production model and soymeal-based fry and fingerling feeds. Fish were stocked in two ponds of size 6.0-mu and 7.8-mu, respectively, at a density of 3,000 mirror carp and 1,000 silver carp fry per mu, and in one pond of size 6.5-mu at an estimated density of 4,600 mirror carp and 1,000 silver carp fry per mu. Mirror carp stocked at 3,000/mu grew from 0.6g to an average weight of 165 g per fish in 85 days of feeding. Gross production averaged 406 kg/mu for mirror carp and 94 kg/mu for silver carp. Average survival rates for mirror carp and silver carp were 82% and 75%, respectively. Mirror carp FCR with the soymeal-based feeds averaged 1.24:1. Average net economic return was RMB 1,305 per mu, for an average return on investment (ROI) of 53.3%. Mirror carp stocked at the estimated density of 4,600/mu grew from 0.6 g to 96 g in 85 days, with an FCR of 1.26:1 and an ROI of 48.6%. Results of the feeding demonstration showed that mirror carp exhibited excellent growth performance, FCR, survival and economic return with the ASA soymeal-based feeds and 80:20 production technology. The use of extruded, floating feed significantly reduced labor costs, lowered fish FCR, avoided feed waste, improved water quality, and made it easier to observe fish feeding behavior and health.

Language
English

Date Published
October 31, 2001

Author
Michael C. Cremer, Zhang Jian and Zhou Enhua