Đề tài Better Breeds of Common Carp (Cyprinus carpio L) for Small-Scale Fish Farmers - Milestone 4

Ministry of Agriculture & Rural Development Collaboration for Agriculture & Rural Development 002/04VIE Project Better Breeds of Common Carp (Cyprinus carpio L.) for Small-scale Fish Farmers Milestone 4: On-farm Trials and Uptake of Improved Breeds of Common Carp Christopher M Austin1, Tuan Anh Pham2, Binh Thanh Thai2, Hung Quang Le2 1School of Science and Primary Industries, Charles Darwin University, Darwin Northern Territory 0909, Australia 2Research Institute for Aquaculture No 1, Dinh Bang, Tu Son, Bac Ninh, Vietnam October, 2007 2 Contents Contents........................................................................................................... 2 List of Figures ................................................................................................. 3 List of Table .................................................................................................... 4 1. Introduction ................................................................................................ 6 2. Materials and methods............................................................................... 7 2.1. Experimental Design..................................................................................................7 2.2. Selection of common carp strains ..............................................................................8 2.3. Common carp rearing and experimental procedures .................................................9 2.4. Data collection and analysis.....................................................................................11 3. Results........................................................................................................ 14 3.1. Fingerling growth rate..............................................................................................14 3.2. Growth and survival of HP3 and LOC strains and effects of feed input .................14 3.3. Growth rate and survival of HP3, H3B and LOC strains ........................................17 3.4. Growth rate and survival for HP3, VNW and LOC Strains ....................................19 3.5. Growth rate and survival of HP3, H3B, VNW and LOC strains in low feed input farms controlled for variation among farmer ponds ..................................................21 3.6. Common carp biomass production in farms stocked with three common carp strain (HP3, H3B, LOC) ......................................................................................................23 3.7. Common carp biomass production comparing farms stocked with two common carp strains (HP3 and LOC). ......................................................................................25 3.8. Demand of the improved common carp seed ..........................................................27 4. Conclusion and Recommendations......................................................... 29 Appendices .................................................................................................... 33 Reference ....................................................................................................... 34 3 List of Figures Fig 2.1. Rice field used for farm trials in Yen Bai province.................................................9 Fig 2.2. Farmer’s pond in Thai Nguyen province.................................................................9 Fig 2.3. Measuring common carp. ......................................................................................11 Fig 2.4. Ethnic people harvesting common cap in rice field in Yen Bai province .............12 Fig 2.5. Harvesting common carp in pond in Thai Nguyen................................................13 Fig 2.6. A farmer is happy with common carp growth.......................................................13 Fig 3.1. Daily growth rate of HP3 and LOC common carp strains in each of 18 farms.....15 Fig 3.2. Example of relative growth of three strains of common carp in rice field in Yen Bai province after six months of culture.................................................................18 Fig 3.3. Daily growth rate of HP3, H3B and LOC common carp strain in each of 11 farms in Yen Bai and Thai Nguyen provinces..................................................................18 Fig 3.4. Daily growth rate of HP3, VNW and LOC common carp strain for a period of 10 months in each farm in Yen Bai and Thai Nguyen provinces. ...............................20 Fig 3.5. Daily growth rate of HP3, H3B, VNW and LOC common carp strains in 3 farms. ................................................................................................................................22 Fig 3.6. Common carp from HP3 strain after seven months of cultured in a high input feed farm in Thai Nguyen province................................................................................23 Fig 3.7. Proportion of genetically improved common carp fry and fingerlings cultured in Vinh Phuc, Thai Nguyen and Yen Bai provinces during 2004-2006. ....................29 4 List of Table Table 2.1. Farms, pond type, and number of fish stocked of each strain (some farms were remove from the data set because fish escaped during flooding). ..........................10 Table 2.2. Data analyses for common carp culture farm trails ...........................................13 Table 3.1 Mean (± SD) of body length and weight of fingerling carp after 60 days of nursing ....................................................................................................................14 Table 3.2. ANOVA table testing for differences in daily growth rate in relation to the effects of common carp strain (HP3 and LOC) and type of feed input. .................15 Table 3.3. Daily growth rate of HP3 and LOC common carp strain for period of 10 months in 18 farms in two type of feeding regimes in Yen Bai and Thai Nguyen provinces. Superscripts indicate significant differences among groups based on Tukey’s test. ................................................................................................................................15 Table 3.4. ANOVA table testing for differences in survival rate in relation to the effects of common carp strain (HP3 and LOC) and type of feed input. .................................16 Table 3.5. Survival rate of HP3 and LOC common carp strains grown for a period of 10 months in 18 farms with two types of feeding rates in Yen Bai and Thai Nguyen provinces. Superscripts indicate significant differences among groups based on Tukey’s test.............................................................................................................16 Table 3.6. ANOVA table testing for differences in daily growth rate in relation to the effects of common carp strain (HP3, H3B and LOC).............................................17 Table 3.7. Daily growth rate of HP3, H3B and LOC common carp strains grown for a period of 10 months in 11 farms in Yen Bai and Thai Nguyen provinces. Superscripts indicate significant differences among groups based on Tukey’s test. ................................................................................................................................17 Table 3.8. ANOVA table testing for differences in survival rate in relation to the effects of common carp strains (HP3, H3B and LOC). ..........................................................19 Table 3.9. ANOVA table testing for differences in daily growth rate in relation to the effects of common carp strain (HP3, VNW and LOC)...........................................19 Table 3.10. Daily growth rate of HP3, VNW and LOC common carp strains grown for a period of 10 months in 5 farms in Yen Bai and Thai Nguyen provinces. 5 Superscripts indicate significant differences among groups based on Tukey’s test. ................................................................................................................................20 Table 3.11. ANOVA table testing for differences in survival rate in relation to the effects of common carp strains (HP3, VNW and LOC).....................................................21 Table 3.12. ANOVA table testing for differences in daily growth rate in relation to the effects of common carp strain (HP3, H3B, VNW and LOC) .................................21 Table 3.13. Daily growth rate of HP3, H3B, VNW and LOC common carp strains for period of 10 months in 3 farms in Yen Bai and Thai Nguyen provinces. Superscripts indicate significant differences among groups based on Tukey’s test. ................................................................................................................................22 Table 3.14. ANOVA table testing for differences in survival rate in relation to the effects of common carp strains (HP3, H3B, VNW and LOC) and culture types (low and high feed input). ......................................................................................................23 Table 3.15. Biomass of common carp strains in 11 farms with 3 strains (HP3, H3B and LOC) and cultured for 300 days in Yen Bai and Thai Nguyen provinces..............24 Table 3.16. ANOVA analyses of biomass of HP3, H3B, and LOC common carp strains.25 Table 3.17. ANOVA analysis of biomass of HP3 and LOC common carp strains. ...........25 Table 3.18. Biomass of common carp strains in 18 farms with 2 strains (HP3 and LOC) cultured for 300 days. Superscripts indicate significant differences among groups based on Tukey’s test..............................................................................................26 Table 3.19. Biomass of HP3 and LOC common carp strains grown for a period of 10 months in 18 farms with two types of feed input in Yen Bai and Thai Nguyen provinces. ................................................................................................................27 Table 3.20. Number of hatcheries and fry nursing farmers in 3 provinces. .......................27 Table 3.21. Number of common carp fry produced in five hatcheries in Thai Nguyen, Yen Bai and Vinh Phuc provinces in 2006.....................................................................28 Table 3.22. Proportion of fry produced from genetically improved common carp lines in five hatcheries in Thai Nguyen, Yen Bai, and Vinh Phuc provinces in 2006. .......28 6 1. Introduction In Vietnam aquaculture plays a very important role in economic development and food security for small scale farmers and contributes 35% of Vietnamese protein consumption. Aquaculture production is increasing at rate of 10% per year and contributes significantly to the country’s export income (MOFI, 2007). Common carp is one of the most popular freshwater aquaculture species in Vietnam and is cultured in pond, cages, reservoir and rice field for household consumption and income generation. A recent survey of 133 carp farmers indicated that pond and rice field production are the preferred form of culture systems (98%) with the pond culture the most common (Austin et al., 2007a). Most farmers culture common carp with up to 8 other fish species, both indigenous (silver carp, black carp) and exotic (silver grass carp, bighead, rohu, mrigal, pirapitinga, Tilapia). In polyculture ponds, common carp is the predominate species making up 30.1% of the biomass based on a recent survey (Austin et al., 2007a). The level of culture intensity for common carp varies from small scale extensive farming, with fish deriving all their nutrition from natural pond productivity, through semi- intensive farming using fertilization from organic material such as bran, agriculture by- products and household wastes to high intensive culture system with high stocking densities and the use of manufactured fish foods. Semi-intensive culture systems are the most popular in Vietnam using ponds or a combination of ponds and rice field cultivation (Austin et al., 2007a). There are many factors that affect production and yield of farmed fish species, including seed (fry and fingerlings) quality, feed type and rate, fertilisation and pond management, including water exchange. Of these, seed quality, which is directly related to the genetic quality of the broodstock used to produce the fry and fingerlings, has been identified as being of major concern to researchers (Thai et al., 2006; 2007), but which is not generally understood by farmers to be a potential issue affecting farm productivity (Austin et al., 2007a). 7 In Vietnam there are many different local varieties of common carp that have been used by farmers but they usually have small size and low growth rate (Tran, 1983). Over recent times the Research Institute for Aquaculture No.1 (RIA-I) has bred genetically improved common carp strains to enhance the productivity of small scale fish farms that utilise this species. This program has used crossbreeding and mass and family selection methodologies to produce genetically improved strains and is considered to have achieved an average increase of 5% in growth rate per generation over a number of generations (Thien and Thang, 1992). However, all the selective breeding and associated growth trials have been conducted in research ponds, often without the availability of unselected lines as control populations for comparative studies. As a consequence, on-farm growth trials of different strains were undertaken to allow for a more effective analysis of carp growth under environments directly relevant to small scale carp farmers and as a strategy to encourage uptake by farmers of genetically improved strains. This report presents, firstly, a report on the statistical analysis of growth and production of different common carp strains in small scale farmer ponds in Yen Bai and Thai Nguyen provinces. The farmers participating in this research project included those using both pond and rice field culture from mostly highland environments. All farmers had previously participated in the socio-economic survey and one of two workshops on fish breeding and genetic improvement conducted as part of this project. Secondly, a survey of the uptake of improved breeds by producers is presented. 2. Materials and methods 2.1. Experimental Design The original objective of the on-farm trials was to compare a genetically improve carp strain and a local strain communally reared in six ponds owned by different farmers. With additional support from the Research Institute of Aquaculture No. 1 (RIA1), the experimental objectives were scaled up to include 37 separate farmers and four strains. The majority (34) of farmers used ponds as their culture systems with six farmers using 8 rice field systems, which reflects the proportion of these different farming systems in these provinces based on the socio-economic survey (Austin et al., 2007a) (Fig 2.1&2.2). Farms were classified according to their levels of feed inputs as either high or low to determine if this important management aspect influenced the relative performance of the different carp strains. Farmers who did not provide food more than once per month were classified as having “Low” input pond systems and those who fed at least once per week or more frequently were classified as having “High” input pond systems. The experiment was conducted over a 12 months period from March 2006 to March 2007, which included spawning and fry rearing March – May, 2006 and fingerling grow out May 2006 to March 2007, which largely coincides with the normal carp farming culture cycle. The trials were conducted in pond systems owned by 20 households in each of the Thai Nguyen and Yen Bai provinces. Representatives of these households were interviewed for the socio- economic survey and participated in one of the farmer workshops on fish breeding and selection held as part of this project. As described in more detail below the experimental design could not be achieved due to differential reproduction and survival of fry. Thus different farms were stocked with different numbers of strains and in varying combinations. Further, fish could not be harvested from several farms due to flooding and other management problems. Appendix 1 lists the farms that participated in the project, and details of their culture systems and fish that were stocked and if data collection at harvest was possible. 2.2. Selection of common carp strains Fours common carp strains were used for growth trials and included one strain (HP3) recently produced through hybridization between the three blood Hungarian strain and a recently imported pure line of Hungarian carp, the three blood Hungarian strain (H3B), an unselected Vietnamese strain (VNW) and a locally available strain (LOC) produced from broodstock available from the Yen Bai provincial hatchery. Genetic analysis of this strain (Thai et al., 2006: 2007) indicates it represented a mixture of Indonesian, Hungarian and Vietnamese strains with the latter strain predominating. 9 . Fig 2.1. Rice field used for farm trials in Yen Bai province Fig 2.2. Farmer’s pond in Thai Nguyen province 2.3. Common carp rearing and experimental procedures Common carp breeding was undertaken at the National Broodstock Centre Hai Duong. Broodstock of each experimental strain were induced to breed on the same day, using standard practices for gamete stripping and fertilization (Thai and Ngo, 2004). Between 10 -12 families of fish were obtained from each strain. After fertilization eggs produced from 10 different families of the one strain were pooled and raised in 200l upwelling incubators. After 4-5 days when larvae had reached 8-12 mm they were transferred to four ponds and stocked at a rate of 100 larvae/m2 and grown for a period of two months. Every effort was made to keep the conditions under which the fry and fingerlings of each strain were raised as similar as possible, especially in relation to stocking density and feeding regime. When the fingerlings had reached of 3-5g, they were tagged by using Coded Wire Tag (CWT). The strains of common carp lines were marked by placing the CWTs on different locations on the body. The tagged fish were stocked into 40 ponds or pond-rice field systems over a two day period. Communally stocked fish were in equal proportions with the exception of three ponds. The details of the fish stocked in farms is given Table 2.1. Table 2.1. Farms, pond type, and number of fish stocked of each strain (some farms were remove from the data set because fish escaped during flooding). Farm Provinces Culture Area Feed systems (m2) input HP3 H3B VNW LOC Total Hoan Yen Bai Ricefield 1000 HF 100 100 100 300 Ly Yen Bai Pond 800 LF 120 120 240 Thuan Yen Bai Pond 1000 LF 100 100 100 300 Tap Thai Nguyen Pond 800 HF 120 120 240 Tuan Thai Nguyen Pond 1000 LF 100 100 100 300 Chung Yen Bai Pond 1000 HF 100 100 100 300 Lien Yen Bai Ricefield 1500 LF 113 113 113 113 450 Hom Yen Bai Ricefield 800 LF 80 80 80 240 Tho Yen Bai Pond 450 HF 75 75 150 Dieu Thai Nguyen Pond 600 LF 100 100 200 Ha Thai Nguyen Pond 1500 LF 113 113 113 113 450 Lieu Thai Nguyen Pond 1000 LF 145 55 100 300 Canh Thai Nguyen Pond 400 HF 60 60 120 Luat Thai Nguyen Pond 1000 LE 100 100 100 300 Nhan Yen Bai Pond 1500 LE 113 113 113 113 450 Truong Thai Nguyen Pond 500 HF 75 75 150 Que Thai Nguyen Pond 1000 LF 100 50 150 300 Vinh Thai Nguyen Pond 800 LF 80 80 80 240 Ke Thai Nguyen Pond 550 LF 90 90 180 Thong Yen Bai Pond 1000 LF 100 100 100 300 Lich Thai Nguyen Pond 500 LF 75 75 150 Trung Thai Nguyen Pond 400 LF 60 60 120 Strain and No of fish stock