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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
Description

A feeding demonstration trial was conducted at the Jiaguanghu Fish Farm in Huainan City, Anhui Province, to demonstrate fingerling to market growth performance of channel catfish using the ASA 80:20 pond production model and soy-based feed. This was the second year of a two-year trial at the Jiaguanghu farm that began in 2000 with a catfish fry to fingerling pond trial. In the 2001 trial, catfish fingerlings were stocked in three ponds of size 3.0-mu each at a density of 600 channel catfish and 100 silver carp fingerlings per mu. Catfish were fed a 32/6 extruded, floating pellet feed formulated as an all-plant protein ration, with soybean meal as the primary protein source. Channel catfish grew from 59 g to an average weight of 672 g per fish in 156 days of feeding. Gross production of channel catfish and silver carp averaged 402 kg/mu and 77 kg/mu, respectively. Average survival rates for channel catfish and silver carp were 99.7% and 98.5%. Channel catfish FCR with the soymeal-based feeds averaged 1.44:1. Average net economic return was RMB 1,633/mu. Return on investment (ROI) averaged 35.5%. The ASA 80:20 technology and extruded, soy-based feeds simplified production management and yielded better fish performance and improved water quality, and required less labor, than the farm’s traditional practices. Harvested catfish were of uniform size, and had good body shape and minimal fat deposition. No off-flavor was experienced in fish from the three trial ponds. Local farmers visited throughout the trial to monitor progress and expressed interest in adopting the technology and feed based on their observations of catfish performance.

Language
English

Date Published
October 31, 2001

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

A feeding trial was conducted at the Xu Xing Zhuang Fish Culture Farm in Beijing to demonstrate fry to fingerling growth performance of longnose catfish (Leiocassis longirostris) using the ASA 80:20 pond production model and soymeal-based fry and fingerling feeds. Fish were stocked in three ponds of size 5.0-mu each at a density of 5,000 longnose catfish and 1,000 silver carp fry per mu. Catfish were fed a combination of soymeal-based 41/11 fry and 36/7 fingerling feeds. Longnose catfish grew from 0.8 g to an average weight of 45 g per fish in 110 days of feeding. Gross production averaged 186 kg/mu for longnose catfish and 70 kg/mu for silver carp. Average survival rates for longnose catfish and silver carp were 83% and 100%, respectively. Longnose catfish fed the combination of ASA soy-based feeds yielded an average FCR of 1.18:1. Average net economic return was RMB 1,921 per mu. Return on investment (ROI) averaged 33.6%. Longnose catfish exhibited good growth performance, FCR, survival and economic return in this trial, and are a promising pond culture species in feed-based production systems for the China freshwater aquaculture industry.

Language
English

Date Published
October 31, 2001

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

A feeding trial was conducted at the Harbin West Suburb Fish Farm in Heilongjiang Province to demonstrate the fingerling to market growth performance of bigmouth buffalo fish using the ASA 80:20 pond production model and a soymeal-based growout feed. Fish were stocked in two, 7-mu ponds at densities of 800 bigmouth buffalo and 100 silver carp fingerlings per mu. Bigmouth buffalo grew from 60 g to an average weight of 464 g per fish in 120 days of feeding. Gross production averaged 337 kg/mu for bigmouth buffalo and 82 kg/mu for silver carp. Average survival rates for bigmouth buffalo and silver carp were 90.7% and 93.5%, respectively. Bigmouth buffalo FCR with the all-plant protein, soymeal-based feed was 0.99:1. Average net economic return was RMB 2,514/mu per mu at market prices of RMB 16.2/kg for bigmouth buffalo and RMB 2.4/kg for silver carp. Average ROI per mu was 80.2%. Results of the feeding demonstration showed that bigmouth buffalo fed well on the extruded, floating feed, and exhibited good growth performance, FCR, survival and economic return with the ASA soymeal-based feed and 80:20 production technology. Bigmouth buffalo appeared to have been underfed in the trial, and it is recommended to increase the feeding rate if larger fish are required for the market.

Language
English

Date Published
October 31, 2000

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

A feeding demonstration trial was conducted at the Jiao Gang Hu Fish Farm in Huainan, Anhui Province, to demonstrate fry to fingerling growth performance of channel catfish using the ASA 80:20 pond production model and soymeal-based fry and fingerling feeds. Fish were stocked in three, 3-mu ponds at a densities of 8,000 channel catfish fry and 1,000 silver carp fry per mu. Channel catfish grew from 1.6 g to an average of 49.3 g per fish in 101 days of feeding. Gross production averaged 353.5 kg/mu for channel catfish and 50.1 kg/mu for silver carp. Average survival rates for channel catfish and silver carp were 89.4% and 81.5%, respectively. Channel catfish FCR for the combination of ASA 41/11 fry and 36/7 fingerling feeds was 0.93:1. Average net economic return was RMB 5,665/mu per mu, and average ROI was 110.7%. Channel catfish exhibited good growth, feed conversion, survival and economic return with the ASA 80:20 pond technology and soymeal-based feeds. Compared to normal production of channel catfish at the Jiao Gang Hu Fish Farm, fish survival was reported to have increased by 25-30%, FCR was reduced by 100%, and ROI was increased by >60% with the ASA technologies and feeds.

Language
English

Date Published
October 31, 2000

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

Crucian carp fingerlings were grown to market size in ponds in Chengdu using the ASA 80:20 production model and a combination of local and ASA soymeal-based growout feeds. Fish were stocked in three ponds of approximately 3-mu each at 2,000 crucian carp per mu together with 150 silver carp fingerlings per mu. Crucian carp were stocked at size 20 g and grew to an average weight of 214 g per fish in 164 days of feeding. Gross production averaged 406 kg/mu for crucian carp and 137 kg/mu for silver carp. Net production for crucian carp averaged 366 kg/mu for the 9.9 mu of trial ponds. Average crucian carp survival was 95%. FCR for the combination of local and ASA feeds was 1.63:1. Net economic return was RMB 645 per mu. ROI ranged from 10% to 30.4% for thethree trial ponds. The average ROI for the three ponds was 21.2%. Low economic return in one of the ponds was the result of a silver carp fish kill in mid-August. Results of the feeding demonstration showed that crucian carp reached the target market size 15 days ahead of schedule using the ASA technology and feed.

Language
English

Date Published
October 31, 2000

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

Fry to fingerling growth performance of Beijing and Suzhou strains of crucian carp were compared in a 4-month feeding trial at the Beijing Xu Xing Zhang Fish Culture Farm. Crucian carp were grown in ponds using the ASA 80:20 production model and soymeal-based 41/11 fry and 36/7 fingerling feeds. Fish stocking density was 5,000 crucian carp fry and 1,000 silver carp fry per mu. Each fish strain was replicated in three ponds. The local Beijing strain of crucian carp grew from 0.6 g to 55 g in 122 days of feeding. Suzhou strain crucian carp imported from a fish farm in Suzhou, Jiangsu Province, grew from 0.6 g to 60 g in the same period. Growth of the Suzhou strain crucian carp was significantly better (P<0.05) than the local Beijing strain. FCR was 1.42:1 for the Beijing strain and 1.34:1 for the Suzhou strain, and was also significantly different (P<0.05). Net income was 15.4% higher and ROI 13.2% higher for the Suzhou strain crucian carp. Results of the trial indicate that the Beijing farm should upgrade its crucian carp breeding stock to a superior strain.

Language
English

Date Published
October 31, 2000

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

A feeding trial was conducted at the Jin Shan Bao Fish Farm in Harbin, Heilongjiang Province, to demonstrate the fingerling to market growth performance of grass carp using the ASA 80:20 pond production model and a soymeal-based growout feed in northeastern China. Harbin is located at 46o north latitude. Fish were stocked in two ponds of approximately 5-mu size at densities of 600 grass carp and 100 silver carp fingerlings per mu. Grass carp grew from 60 g to an average weight of 777 g per fish in 138 days of feeding. Gross production averaged 424 kg/mu for grass carp and 87 kg/mu for silver carp. Average survival rates for grass carp and silver carp were 91% and 98%, respectively. Grass carp FCR with the all-plant protein, soymeal-based feed was 1.54:1. Average net economic return was RMB 896 per mu, for an average return on investment of 36.8%. Results of the feeding demonstration showed that grass carp fed well on the extruded, floating feed, and exhibited good growth performance, FCR, survival and economic return with the ASA soymeal-based feed and 80:20 production technology.

Language
English

Date Published
October 31, 2000

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

Grass carp growth performance in ponds was compared with two isonitrogenous feeds with different energy and fiber levels. One feed was the standard ASA/China 32/6 freshwater carp growout feed. This feed was formulated to contain 32% crude protein, 6% fat and 2.7% fiber, with dehulled soybean meal as the primary protein source. The second feed was a new ASA 32/3 grass carp growout feed formulated to contain 32% crude protein, 3% fat and 8% fiber, with standard soybean meal as the primary protein source and soy hulls as the fiber source. Both feeds were fed in extruded, floating pellet form to grass carp in a 6-month pond trial at the Xu Xing Zhuang Fish Culture Farm in Beijing. Grass carp fed the ASA 32/6 carp growout feed grew from 100 g to 825 g in 174 days with an FCR of 1.23:1. Grass carp fed the ASA 32/3 grass carp feed grew from 100 g to 815 g in 174 days with an FCR of 1.27:1. Fish growth was significantly different with the two feeds (P<0.05), but there was no significant difference in FCR (P>0.05). Gross production with the 32/6 carp growout feed was 513.7 kg/mu (7,706 kg/ha) for grass carp and 136.1 kg/mu (2,042 kg/ha) for silver carp. Gross production with the 32/3 grass carp feed was 502.3 kg/mu (7,535 kg/ha) for grass carp and 139.0 kg/mu (2,085 kg/ha) for silver carp. The ratio of fed grass carp to filter feeding silver carp was 79/21 and 78/22 for the 32/6 and 32/3 feeds, respectively. Net income per mu was RMB 871 for the 32/6 feed and RMB 1,068 for the 32/3 feed. Return on investment (ROI) was 23.9% with the 32/6 feed and 31.7% with the 32/3 feed. Net income per mu was 22.6% higher and ROI 32.6% higher with the low-fat, high- fiber 32/3 grass carp feed than with the 32/6 carp growout feed because of the significantly lower cost of the 32/3 feed.

Language
English

Date Published
October 31, 2000

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

Japanese sea bass (Lateolabrax japonicus) growth in cages was evaluated from small fingerling to market size during the 1999 and 2000 production seasons at Nan Ji Island along the east coast of China. Growth from fingerling to sub-market size was evaluated in 1999 with soymeal-based and fishmeal-based feed rations formulated to contain 43% protein and 12% fat, and from sub-market to market size in 2000 with the 43/12 soymeal-based feed ration. The soymeal- and fishmeal-based rations were formulated to be isonitrogenous and isocaloric and were fed in an extruded pellet form. In June 1999, fish were stocked in 8.0-m3 cages at 350 fish per m3 and fed for 153 days. Sea bass grew from 3 g to 297g with the soymeal-based ration, and from 3 g to 289 g with the fishmeal-based ration. There was no significant difference (P>0.05) in fish growth or feed conversion efficiency with the two feeds. FCR averaged 1.53:1 and 1.55:1 for the soymeal- and fishmeal-based rations, respectively. Survival averaged 50% for all cages and treatments. The sea bass were over-wintered and restocked in 8.0-m3 cages at 175 fish per m3 in late April 2000. Sea bass grew from 302 g to 527 g in 90 days on the soymeal-based ration, with an average FCR of 1.54:1. Fish survival averaged 93%. Gross fish production averaged 85.9 kg/m3. Net profit was RMB 28,559 for the three trial cages, or RMB 1,190/m3, at an August 2000 market price of RMB 36/kg.

Language
English

Date Published
October 24, 2000

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

Japanese sea bass (Lateolabrax japonicus) growth in cages was evaluated from fingerling to sub-market size with extruded pellet and fresh fish rations in an ASA feeding trial at Xiangshan, Ningbo along the coast of Zhejiang Province, China. The extruded feed was a soymeal-based ration containing 43% crude protein and 12% fat and fed in extruded, floating pellet form. Fresh fish was fed in chopped form. Sea bass fingerlings were stocked in 8.0-m3 cages at 200 fish per m3. Sea bass grew from 10.6 g to 178.3 g in 102 days on the ASA extruded feed, with an FRC of 1.82:1, and from 11.0 g to 178.3 g in 102 days on the fresh fish ration, with an FCR of 6.78:1. Gross production averaged 31 kg/m3 with the extruded feed and 29.6 kg/m3 with the fresh fish ration. Net income and ROI were RMB 478/m3 and 62.7%, respectively, for sea bass fed the extruded ASA feed, and RMB 341/m3 and 40.4% for sea bass fed the fresh fish diet. Feed cost per kilogram of fish growth was RMB 9.46 with the ASA feed and RMB 14.92 with the fresh fish diet. Results demonstrated a 40% higher net income, 55% higher ROI, and 37% lower feed cost with the soymeal-based extruded feed than with a traditional fresh fish diet. The added benefits of quality consistency, less nutrient loading of the aquatic environment, ease in shipping and storing, and absence of potential pathogens make manufactured feed a better choice than fresh fish for feeding Japanese sea bass.

Language
English

Date Published
October 31, 2000

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

Growth performance of normally pigmented and albino channel catfish was compared in cages at Min Qing Reservoir in Fujian Province. Catfish were cultured in floating cages using the ASA LVHD cage technology model and a soymeal-based, 32% protein floating feed. Normally pigmented and albino channel catfish were stocked in six, 1-m3 cages at a density of 400 fish/m3. Each treatment was replicated in three cages. Normally pigmented channel catfish grew from 83 g to 494 g in 142 days of feeding. Albino catfish grew from 83 g to 392 g in the same period. FCR was 1.56:1 for the normal catfish and 1.67:1 for the albino catfish. Gross production and survival averaged 193.8 kg/m3 and 90.4% for the normal catfish, and 148.8 kg/ m3 and 91.5% for the albino catfish. Fish growth, survival and production per m3 were significantly higher (P<0.05) for the normally pigmented catfish group, but there was no significant difference in FCR (P>0.05) for the two groups. Average net economic return and ROI for the normal catfish were RMB 1,384/m3 and 72.4%, respectively. Average net economic return and ROI for the albino catfish were RMB 1,309/m3 and 70.8%. Net return and ROI were significantly different (P<0.05). Normally pigmented catfish yielded a higher net return and ROI than albino catfish, despite albino catfish having a 29% higher market value. Results of this trial were opposite of U.S. studies that found no production differences between normally pigmented and albino channel catfish, and indicate there is probably significant inbreeding in the albino catfish stock tested in this trial.

Language
English

Date Published
October 31, 2000

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

Sub-market size yellow croaker (Pseudosciaena crocea) were weaned from a fresh fish diet to an extruded pellet feed and grown to market size in cages in ASA feeding trials at Nanji Island, Wenzhou, and Xiangshan, Ningbo. The extruded feed was a soymeal-based ration containing 43% crude protein and 12% fat and fed in extruded, floating pellet form. Yellow croaker were stocked in 22.5-m3 cages at 31 fish per m3 in the Wenzhou trial, and at 75 fish per m3 in 8-m3 cages in the Ningbo trial. In the Wenzhou trial, yellow croaker grew from 164 g to 327 g in 123 days on the extruded feed, with an FRC of 1.67:1 and 96.7% survival. Net income for the Wenzhou trial was RMB 7,043 per cage, or RMB 313/m3 for the 22.5-m3 cages. ROI was 83.2%. In the Ningbo trial, yellow croaker grew from 103 g to 248g in 118 days on the extruded feed, with an FRC of 2.24:1 and 93.3% survival. Net income for the Ningbo trial was RMB 3,480 per cage, or RMB 435/m3 for the 8-m3 cages. ROI was 72%. Fish growth and FCR in the Ningbo trial were affected by a parasitic infestation midway through the trial. Both trials demonstrated good croaker growth performance and economic return with the soymeal-based, extruded feed. High net income and ROI demonstrated the feasibility of weaning sub-market size yellow croaker from fresh fish to an extruded feed and growing them to market size on the extruded feed. The added benefits of quality consistency, less nutrient loading of the aquatic environment, ease in shipping and storing, and absence of potential pathogens make extruded feed a superior choice than fresh fish for feeding yellow croaker in cages.

Language
English

Date Published
October 31, 2000

Author
United States Soybean Export Council