Aquaculture and Nutrition Research in Thailand

摘要

Traditionally fisheries have been playing an important role in Thailand in providing food,income and employment to rural people,and more recently earning foreign exchange for the country via export.The contribution of fisheries to gross domestic product in 2001 was 2.4%.The contribution of fisheries to agricultural sector was 24%.Total fisheries production in 2000 is 3,713,000 metric tons(MT) and approximately 80% of this production is from capture and 20% from aquaculture,but in terms of value,the aquaculture contribute to 65% of total fisheries production value. Aquaculture in Thailand has grown rapidly over the last 15 years.This expansion mainly came from shrimp culture.Contrarily,expansion of fish culture has been relatively slow primarily due to limited export market and low price.Eighty percent of freshwater prawn,90% of the freshwater fish,and 70% of the seabass production was for domestic consumption.On the other hand,80% of marine shrimp and grouper production were meant for export.Thailand currently provides over 190,000 hectares of land for aquaculture production with approximately 40% this area is used for shrimp culture. The total aquaculture production in Thailand in 2000 amounts to approximately 738,000 MT.Nearly 34% of the total product is the shrimp.Prior to 2003,P.monodon was the main shrimp species cultured in the country.Recently,white shrimp {Penaeus vannamei) has been introduced and is becoming the specie of choice,owing to its relatively fast growth rate.Total shrimp production in the country jumped from 10,000 MT in 1987 to 250,000 MT in 1994.Due to viral disease outbreak,the total shrimp production slumped to 170,000 MT in 1997 but since then a gradual recovery has lead to 320,000 MT production in 2001.In 2002 and 2003,the production of P.monodon fell to 260,000 and 180,000 MT respectively,mainly because of the slow growth problem and stringent export regulations.The major limitations for shrimp culture remain to be a lack of genetically well-selected and healthy brood-stock,a lack of sustainable rearing technology,and a lack of cost effective quality feeds.The feed industry is now rapidly improving as it is expanding to meet the domestic needs.In 1982 this industry was represented by only one feed mill.By 1987 this number grew to five feed mills,further increasing to a total of 31 in 1999 and 43 feed mills in 2004.Expansion in shrimp farming have been fast,however,not well matched by the research conducted with shrimp nutrition and shrimp culture technology. The aquaculture nutrition research in Thailand encompasses a wide range of species.Together with the fact that meager funds are available for this research,the nutrient requirements of several of these species have not been fully established.Also,most of the data so obtained at laboratory scale may find a limited application under pond conditions.A recent research focus have been to address nutrient needs of species newly introduced to aquaculture.Effects related to probiotics,peptidoglycan,β glucans,and astaxanthin have been extensively studied in black tiger shrimp.Research on the use of medicinal plant extracts for enhancing immune function,disease prevention or disease control in shrimp,and on the effect of different hormones on reproductive efficiency of P.monodon have also caught quite an attention.Currently I have been investigating the development of complete feed for commercial culture of abalone(Haliotis asinina) as well as the effect of three Thai medicinal plant species on growth,survival and disease resistance in P.monodon;and the data will be presented at this meeting.The species which received more attention in nutrition research among marine forms include the tiger prawn(P.monodon),abalone(Haliotis asinina),and the swimming crab(Portunus pelagicus) whereas among freshwater forms include the giant freshwater prawn(Macrobrachium rosenbergii),tilapia(Tilapia nilotica),and the catfish(Clarius sp.).