Tài liệu Optimisation of artemia biomass production in salt ponds in vietnam and use as feed ingredient in local aquaculture

Optimisation of Artemia biomass production in salt ponds in Vietnam and use as feed ingredient in local aquaculture Nguyen Thi Ngoc Anh Promoter: Prof. Dr. Patrick Sorgeloos Laboratory of Aquaculture & Artemia Reference Center Faculty of Bioscience Engineering, Ghent University Co-promoter: Dr. Nguyen Van Hoa College of Aquaculture & Fisheries, Can Tho University, Vietnam Dean: Prof. Dr. ir. Guido Van Huylenbroeck Rector: Prof. Dr. Paul Van Cauwenberge Examination Committee and Reading Committee (*): Prof. Dr. ir. Jacques Viaene (Chairman) Department of Agricultural Economics, Faculty of Bioscience Engineering, Ghent University. [email protected] Prof. Dr. Peter Goethals (Secretary) Department of Applied ecology and environmental biology, Faculty of Bioscience Engineering, Ghent University. [email protected] Prof. Dr. Patrick Sorgeloos (Promoter), Department of Animal Production, Faculty of Bioscience Engineering, Ghent University), [email protected] Prof. Dr. ir. Peter Bossier (Department of Animal Production, Faculty of Bioscience Engineering, Ghent University), [email protected] *Dr. Nguyen Van Hoa (Co-promoter), College of Aquaculture & Fisheries, Can Tho University, Vietnam. [email protected] *Prof. dr. Johan Mertens (Department of Biology, Faculty of Sciences, Ghent University) [email protected] *Prof. Dr. Josse De Baerdemaeker (Laboratory of Agricultural Machinery & Processing, Department of Agro-Engineering and Economics, Katholic University of Leuven). [email protected] *Dr. Roeland Wouters (INVE Technologies, Belgium), [email protected] Nguyen Thi Ngoc Anh Optimisation of Artemia biomass production in salt ponds in Vietnam and use as feed ingredient in local aquaculture Thesis submitted in fulfilment of the requirements for the degree of Doctor (PhD) in Applied Biological Sciences Dutch translation of the title: Optimalisatie van Artemia biomassa productie in zoutpannes in Vietnam and gebruik als voeder-ingredient in lokale aquacultuur To cite this work: Anh, N.T.N. (2009) Optimisation of Artemia biomass production in salt ponds in Vietnam and use as feed ingredient in local aquaculture. PhD thesis, Ghent University, Belgium. The author and the promoters give the authorisation to consult and to copy parts of this work for personal use only. Every other use is subject to the copyright laws. Permission to reproduce any material contained in this work should be obtained from the author. ISBN 978-90-5989-308-5 This study was funded by Vietnamese government, PhD scholarship of the Vietnamese Overseas Scholarship Program (322 project), and the CWO scholarship of the Faculty of Bioscience Engineering, Ghent University, Belgium. Acknowledgements First of all, I would like to express my deep gratitude to my promoter, Prof. dr. Patrick Sorgeloos for giving me the opportunity to study at Ghent University. His scientific orientation, encouragement, and support during my four year study, especially his patience in correcting the papers and final thesis drafts during his already busy time. Special thank to my co-promoter Dr. Nguyen Van Hoa (Can Tho University, Vietnam) for his scientific guidance, encouragement and experience on Artemia research. My sincere thanks go to my supervisors Dr. Gilbert Van Stappen and Mathieu Wille for their devoted and thoughtful revision and recommendations in the preparation and completion of all chapters of the thesis. I sincerely thank Prof. Dr. Josse De Baerdemaeker (Catholic University of Leuven, Belgium), Nguyen Thuan Nhi (College of Technology, Can Tho University) for giving me the basic knowledge and critical suggestions in the design of the experimental solar drier, and Dr. Vu Quang Thanh for instruction in indoor drying techniques and allowing me to utilize the drying machines and equipment, and Phan Thanh Dung for his help during the drying experiment in the College of Technology, Can Tho University. I am grateful to Prof. Dr. Truong Quoc Phu, Dr. Tran Thi Thanh Hien, Dr. Vu Ngoc Ut and Duong Thuy Yen (College of Aquaculture and Fisheries, Can Tho University) for their proper suggestions on experimental designs, feed formulation and for providing me with facilities and space to perform the feeding trials. I am greatly indebted to Peter Baert for his valuable recommendations with data-processing on the Artemia experiments and also willing to help me whenever needed. I am especially thankful to the members of the examination and reading committee, Prof. Dr. ir. Jacques Viaene; Prof. Dr. Patrick Sorgeloos, Prof. Dr. ir. Peter Bossier, Prof. Dr. Johan Mertens, Prof. Dr. Peter Goethals (Ghent University), Prof. Dr. Josse De Baerdemaeker (Catholic University of Leuven), Dr. Nguyen Van Hoa (Can Tho University) and Dr. Roeland Wouters (INVE Technologies NV, Belgium) for their critical reviews and extremely valuable suggestions to improve this thesis. My warmest thanks go to Magda Vanhooren, who kindly helped me whenever needed. I am greatly indebted to Geert Van de Wiele and Anita De Haese for HUFA and proximate composition analyses of the Artemia samples. I deeply thank the staff of ARC: Dorina Tack, Alex Pieters, Marc Verschraeghen, Jean Dhont, Bart Van Delsen, Kristof Dierckens, Marijke Van Speybroeck, Christ Mahieu, Sebastiaan Vanopstal, Brigitte Van Moffaert, Tom Baelemans, Jorg De Smyter, for their help with administrative matters. Special acknowledgements are due to Prof. Dr. Nguyen Anh Tuan, the rector of Can Tho University and Prof. Dr. Nguyen Thanh Phuong, the dean of the College of Aquaculture & Fisheries, for allowing me to study abroad. Many thanks to Dr. Duong Nhut Long, Dr. Nguyen Van Kiem, Dr. Tran Ngoc Hai and Dr. Ngo Thi Thu Thao from the College of Aquaculture & Fisheries for their support and providing me enough free time to accomplish this thesis. I owe special thanks to my colleagues Huynh Thanh Toi for his endless kindness and all his help in Ghent and in Vietnam, Nguyen Thi Hong Van for her provision of scientific journals, encouragement and supporting experimental equipment, Tran Huu Le and Le Van Thong for helping me with filtering chlorophyll a samples, transporting water samples to Can Tho for analysis and biomass collection. I greatly appreciate Le Van Nhieu, Phan Thanh Phuoc, Giang Van Nghiep, Giang Van Hay, Nguyen Duyen Hai, Nguyen Thi Phuong, Tran Thi Yen who have been devoted hard workers in Bac Lieu salt works and for their enthusiasm and efficient support during my field study in Vinh Hau station, Bac Lieu province. Many thanks to my PhD colleagues: El-Magsodi Mohamed, Natrah Ikhsan, Kartik Sri Barua, Gunasekara Asanka, Dang To Van Cam, Le Hong Phuoc, Dinh The Nhan, Nguyen Duy Hoa, Nhu Van Can, Ho Manh Tuan and others for their encouragement and support during my study in Ghent. To all Vietnamese students in Ghent, I thank you for your moral support during my stays in Ghent. I would like to express my warmest feelings to all my friends and my colleagues in various institutions and universities, Can Tho University and College of Aquaculture and Fisheries, who always were concerned about my PhD completion. I am very grateful to the Ministry of Education & Training, Vietnamese Government for providing me with a scholarship to pursue my PhD study and the Faculty of Bioscience Engineering, Ghent University, Belgium through the CWO scholarship for the defence of this thesis. My great gratefulness goes to my grandmother, my aunts, my brothers and sisters who always encouraged me to finish my PhD, especially my mother who always gave me all physical and moral support, but unfortunately does not live anymore. I wish to dedicate this thesis to my husband Phan Huu Tam, who has sacrificed a lot during my four years intensive study. This thesis is a present for him. TABLE OF CONTENTS Chapter 1 General introduction .......................................................................................... 1 Chapter 2 Literature review ................................................................................................ 7 Chapter 3 Culture of Artemia biomass Section I Effect of partial harvesting strategies on Artemia biomass production in salt works ......................................................................................................... 31 Section II Effect of different food supplements on proximate compositions and Artemia biomass production in salt works ................................................ 47 Secttion III Effect of different ratios of N:P on primary productivity: its combination with feeding strategies for Artemia biomass production in salt ponds...... 69 Chapter 4 Drying Artemia biomass Section I Total lipid and fatty acid contents of Artemia biomass dried using different drying techniques .................................................................................... 109 Section II Effect of solar drying on lipid and fatty acid composition of dried Artemia biomass .................................................................................................... 117 Chapter 5 Application of Artemia biomass for target aquaculture species Section I Formulated feeds containing fresh or dried Artemia biomass as live food supplement for larval rearing of black tiger shrimp, Penaeus monodon 151 Section II Effect of fishmeal replacement with Artemia biomass as protein source in practical diets for the giant freshwater prawn Macrobrachium rosenbergii ................................................................................................................. 141 Section III Effect of different forms of Artemia biomass as a food source on survival, molting and growth rate of mud crab, Scylla paramamosain ................. 157 Section IV Substituting fishmeal with Artemia meal in diets for goby Pseudapocryptes elongatus: effects on survival, growth and feed utilization ................................................................................................. 173 Chapter 6 General discussion and conclusions .............................................................. 207 Chapter 7 References ....................................................................................................... 216 Summary/Samenvatting .................................................................................................. 239 Curriculum vitae .............................................................................................................. 247 i List of abbreviations Σ Total °C Degree Cencius ANOVA Analysis of variance AOAC Association of Official Analytical Chemists APHA American Public Health Association ARA Arachidonic acid BHT Butylated hydroxytoluene C:N C-to-N ratio C1 First crab stage Ca Calcium CF Commercial feed cm Centimeter CMI Cumulative mortality index DA Dried Artemia DHA Docosahexaenoic acid DIN Dissolved inorganic nitrogen DRP Dissolved reactive phosphorus DW Dry weight EFA Essential fatty acid EPA Eicosapentaenoic acid FA Fresh/frozen Artemia FAME Fatty acid methyl easters FAO Food and agriculture organization FFA Free fatty acid FM Fish meal g Gram GW Green water h Hour HA Hot air HUFA Highly unsaturated fatty acid L Liter ii LIA Linoleic acid LNA Linolenic acid min Minute MKD Mekong delta ml Milliliter mm Millimeter MoFI Ministry of Fisheries MUFA Mono-unsaturated fatty acid MW Microwave N:P N-to-P ratio P Phosphorus PL Polar lipid PL 15 Postlarvae 15 PM Pig manure PUFA Poly-unsaturated fatty acid RB Rice bran SB Soybean meal SE Standard error SFA Saturated fatty acid TAG Triacylglycerols TAN Total ammonia nitrogen TN Total nitrogen TP Total phosphorus VIAE Vietnam Institute of Agricultural Engineering VND Vietnam dong WW Wet weight iii CHAPTER General introduction and thesis outline 1 2 Chapter 1 General introduction Populations of the brine shrimp Artemia (Crustacea, Anostraca) are typical inhabitants of extreme environments, such as hypersaline inland lakes, coastal lagoons, and solar salt works, distributed all over the world, and characterized by communities with low species diversity and simple trophic structures (Lenz, 1987; Lenz and Browne, 1991). Artemia can be found in a great variety of habitats in terms of water chemistry (Lenz, 1987; Bowen et al., 1988), altitude (Triantaphyllidis et al., 1998; Van Stappen, 2002) and climatic conditions, from humid-subhumid to arid areas (Vanhaecke et al., 1987). The first use of Artemia nauplii, hatched from cysts, is known from the 1930s when this zooplankton organism was used as a suitable food source for fish larvae in the culture of commercially important species (Sorgeloos, 1980b; Léger et al., 1986). Since then, Artemia has been found to be a suitable food for diverse groups of organisms of the animal kingdom, especially for a wide variety of marine and freshwater crustaceans and fishes (Sorgeloos, 1980b). Also decapsulated Artemia cysts, juvenile and adult Artemia have increasingly been used as appropriate diets for different fish and crustacean species (Sorgeloos et al., 1998; Dhont and Sorgeloos, 2002; Lim et al., 2003). Since the early 1990s cyst consumption has increased exponentially as a consequence of the rapidly expanding shrimp and marine fish industries (Sorgeloos et al., 2001; Dhont and Van Stappen, 2003). On the other hand, the limited supply of Artemia cysts, originating from natural harvests, may lead to a serious bottleneck in many aquaculture developments (Lavens and Sorgeloos, 2000b). In particular, in South East Asia where no natural populations of Artemia occur, therefore diversification of Artemia sources has been considered a possible solution to sustain the fast growing aquaculture industry. This strategy has been performed by the exploration of natural harvesting from new Artemia sites such as China (Xin et al., 1994), Iran (Van Stappen et al., 2001), Mexico and Chile (Castro et al., 2006) etc. Furthermore, man-made introduction of Artemia into saltworks and man-made ponds has also contributed to supplement cyst supply. This approach has been conducted during the last couples of decades in several countries with a monsoon climate. For instance, Philippines (De Los Santos et al., 1980), Thailand (Tarnchalanukit and Wongrat, 1987), Vietnam (Quynh and Lam, 1987; Brands et al., 1995) and other countries such as India, Sri Lanka, Iran (Hoa et al., 2007). 1 Chapter 1 In Vietnam, Artemia production is successfully conducted on a seasonal basis in the coastal areas of the Mekong Delta, southern Vietnam (Brands et al., 1995; Baert et al., 1997). To date this region is an important supplier of high-quality Artemia cysts that are used in domestic aquaculture as well as for export. This activity has had significant positive socio-economic impacts for the local rural populations (Hoa et al., 2007; Son, 2008). In practice, cysts produced during the previous culture season are used to establish, by inoculation, a new population of Artemia. This practice may favour the accumulation of adaptations to the new environment (Frankenberg et al., 2000). This Artemia culture system is referred to as semi-intensive (Tackaert and Sorgeloos, 1991) and static (Quynh and Lam, 1987; Brands et al., 1995). Semi-intensive refers to small seasonal man-managed ponds in which Artemia is inoculated at high densities (between 60 and 100 nauplii L-1). Ponds are managed intensively (i.e. inoculation of selected strains, manipulation of primary and secondary production, predator control, etc.) but most of the management procedures are empirical. Furthermore, Artemia production in Vietnam has largely focused on cyst production, and all techniques and methodologies developed to optimize Artemia production have used maximal high-quality cyst production as their primary target (Brands et al., 1995; Baert et al., 1997; Hoa et al., 2007). Artemia is a non-selective particle feeder, feeding on microalgae, detritus and bacteria, where the only limiting factor is the size of the ingested particles (Van Stappen, 1996; Fernández, 2001; Dhont and Sorgeloos, 2002). Although the feeding and filtration biology of Artemia has been studied in laboratory tests (Coutteau and Sorgeloos, 1989; Evjemo and Olsen, 1999; Fernández, 2001), up to now, this type of study has not been extended to the field, and there is very little information on optimal Artemia biomass production in salt works. Artemia biomass is an excellent food source in aquaculture as it converts detritus and phytoplankton into high-quality proteins, thus extracting nutrients from the aquatic environment (Sorgeloos, 1985). Artemia biomass is valorised as a high-quality feed for ornamental fish (Lim et al., 2001; 2003), as a nursery food for marine fish, shrimp, prawn and crab (Merchie, 1996; Sorgeloos et al., 1998; Dhont and Sorgeloos, 2002), as an overall high-protein ingredient for aquaculture feeds, and as maturation trigger in shrimp broodstock (Naessens et al., 1997; Wouters et al., 2002). In pond systems, the success of Artemia cyst and biomass production relies on the favourable growth of the Artemia population after inoculation. This growth is, amongst others, significantly influenced by the food management of the culture ponds. The final 2 Chapter 1 yield of Artemia biomass can also be considerably affected by various technical aspects, such as harvesting strategies (Brands et al., 1995; Baert et al., 1996, Anh and Hoa, 2004). Hence, substantial research is required to (1) optimize culture techniques, in particular in relation to the effects of organic and inorganic fertilizers on the production of microalgae as a natural food for Artemia, (2) on the use of supplementary feeds and (3) on adequate harvesting strategies. Moreover, there is a need for (4) research into the possible applications of Artemia biomass products in Vietnamese aquaculture. Farming of highly valuable aquaculture species in the Mekong delta has been studied for several species such as Penaeid shrimp (Nghia et al., 1997a,b; Phuong et al., 2008), freshwater prawn Macrobrachium rosenbergii (Thang, 1995; Lan et al., 2006). Similar work exists for the mud crab Scylla spp. (Dat, 1999; Ut et al., 2007a,b) and for different types of polyculture of marine and freshwater species (Rothuis et al., 1998; Minh et al., 2001; Lan et al., 2003). Recently, Vietnamese aquaculture activities have been expanding with the culture of new target marine aquatic species such as swimming crab (Portunidae), cobia (Rachycentridae), grouper (Serranidae), goby (Gobiidae), eel (Anguillidae), Areola babylon (Buccinidae), etc. (MoFI, 2006). These new species offer opportunities for diversification in the use of Artemia, including live juveniles and adults as well as frozen or dried Artemia biomass. This indicates that there is a high potential market for Artemia biomass not only in the Mekong Delta but also along the coast line of central Vietnam (Hoa et al., 2007). Research objectives The general objectives of this thesis are firstly to improve Artemia pond management in terms of the supply of natural and supplementary foods, and by adaptation of biomass harvesting strategies. It also aims to develop a simple and cheap processing technique for Artemia biomass, resulting in a product which is suitable for application in local aquaculture operations in the Mekong Delta. 3 Chapter 1 The specific objectives and the thesis outline are as follows: Chapter 1 (General introduction and thesis outline) describes an outline covering the main topics of this thesis. Chapter 2 (Literature study) presents the biology and ecology of Artemia, and gives an overview of aquaculture as well as the history of Artemia study in Vietnam. It comprises general geographic and climatological information on the site where the field research has been conducted. It describes the general principles of Artemia biomass pond production in this area, and its various applications in local aquaculture. It also provides a summary of drying methods currently used in food and feed processing technology. Chapter 3 (Culture of Artemia biomass) describes the experimental work aiming to optimize Artemia biomass production in salt ponds. This chapter consists of three parts: - Effect of partial harvesting strategies on Artemia biomass production in salt works (Section I) - Effect of different food supplements on proximate compositions and Artemia biomass production in salt works (Section II) - Effect of different ratios of N:P on primary productivity: its combination with feeding strategies for Artemia biomass production in salt ponds (Section III) Chapter 4 (Drying Artemia biomass) describes tests aiming to work out a simple and cheap drying method for Artemia biomass, resulting in a product with appropriate quality for use in aquafeeds. It comprises two parts: - Total lipid and fatty acid contents of Artemia biomass dried using different drying techniques (Section I) - Effect of solar drying on lipid and fatty acid composition of dried Artemia biomass (Section II) 4 Chapter 1 Chapter 5 (Application of Artemia biomass for some target aquaculture species) evaluates the potential uses of different Artemia biomass preparations as feeds in the larviculture and nursery phases of the important cultured species in the Mekong delta. It contains four parts. - Formulated feeds containing fresh or dried Artemia biomass as live food supplement for larval rearing of black tiger shrimp, Penaeus monodon (Section I) - Effect of fishmeal replacement with Artemia biomass as protein source in practical diets for the giant freshwater prawn Macrobrachium rosenbergii (Section II) - Effect of different forms of Artemia biomass as a food source on survival, molting and growth rate of mud crab Scylla paramamosain (Section III) - Substituting fishmeal with Artemia meal in diets for goby Pseudapocryptes elongatus: effects on survival, growth and feed utilization (Section IV) Chapter 6 (General discussion) restates and discusses the overall results of the experiments conducted in this thesis. Based on the discussion, the general conclusions are drawn and prospective research topics are proposed. Chapter 7 (References) contains all the bibliographic citations mentioned in this thesis. 5 Chapter 1 6