HomePrevious PageSite Map

Print This Page

 

 

 

A Brief History and Current Status of Shrimp Farming in Thailand

Dr. Brian Hunter Reports That Farmers Adopt Automatic Feeders

 

 

At Nicovita’s Fifth Annual Symposium 2011 in Honduras (November 23, 2011), Dr. Brian Hunter, Director of Aquaculture Business and Technical Development for Diamond V, which markets science-based shrimp feed ingredients in Thailand, gave a presentation titled “‘Shrimp Aquaculture in Thailand—History and Current Status.”  At the University of Arizona, Hunter was Dr. Donald Lightner’s (the famed shrimp virus researcher) first Master’s Degree student in 1979, and he went on to receive his PhD at the University in biochemistry.

 

His talk in Honduras covered: feeding, aeration, closed and semi-closed systems, low salinity pond culture, polyculture—and automatic feeders (see pictures at the end of this report).

 

Some excerpts:

 

By the early 1990’s there were 35,000 Penaeus monodon shrimp farms in Thailand, and 70% of them were family farms with no more than four, one-hectare ponds.  Culture areas were centered in the far south, the east, and just south of Bangkok near the town of Samut Songkhram.

 

During the 1990’s, stocking densities for of P. monodon gradually increased from 25-30 to 60-90 per square meter.  Aeration increased to 15-horsepower per hectare, aided by long-arm paddlewheel aerators powered by land mounted electric or diesel motors.  Water exchange was gradually reduced to about 5% a day.

 

In 1992, the first major viral epizootic hit Thailand.  The effect was particularly severe in the Samut Songkhram area, eventually eliminated almost all shrimp culture in the area.  Whitespot was first reported in monodon in 1994.  Then, soon after its introduction in 2002, whitespot was reported in P. vannamei.  Although the spread of the virus resulted in great harm to the industry, production remained high, above 500,000 metric tons every year.

In the late 1990’s farmers noticed that monodon growth rates were drastically reduced.  After several seasons, the slow growth syndrome was determined to be caused by IHHNV (the infectious hypodermal and hematopoietic necrosis virus).  Since no virus-free, monodon stocks were available, the conversion from monodon to vannamei accelerated.  Currently about 95% of Thai shrimp farms raise mostly vannamei.

 

Thai shrimp farming is currently characterized by small (0.5 to 2.0 hectare) ponds with high aeration rates and low water turnover.  The low water usage has permitted the use of sodium hypochlorite as a cost-effective water disinfectant, used either in treatment ponds, or directly in culture ponds prior to stocking.  Farms are generally small, 4 to 10 ponds, but, recently, pond sizes have been increasing.  Stocking rates average 60-120 postlarvae per square meter.  Nursery culture is rarely used.  Characteristics of Thai shrimp farms and management protocols which have permitted sustained high production levels following the advent of whitespot can be divided into two principal categories: whitespot avoidance and water and pond bottom management to minimize stress.  Thai farmers do not like to exchange more water than necessary, and closed and semi-closed ponds are common.  Another method used by Thai farmers to avoid whitespot has been to move inland to low salinity areas.  At present 25%-30% of shrimp production takes place in these areas.  Thai farmers have developed methods to balance pH and ionic content of culture water to maintain shrimp health in low salinity culture.

 

Stress management in Thai farms includes the use of probiotics and careful management of pond pH and important ions, especially calcium, magnesium, and potassium.  Particular attention is given to low water temperatures they frequently initiate epizootics.  Farmers in southern Thailand previously stocked three crops per season, but now they do not stock during the winter when whitespot epizootics are more severe and the culture rarely profitable.  Paddlewheel aerators provide up to 32-horsepower of aeration per hectare, preventing dawn pond oxygen from dropping below three parts per million.  In addition, the aerators create a sweeping action that keeps solids in suspension, where they can be oxidized.   Pond bottoms stay clean.  Some farmers also use polyculture to help maintain water quality and reduce stress.  Tilapia, tiger shrimp, and macrophytic algae may be cultured along with white shrimp.

 

 

Automatic Feeders

 

   

 

Limited use of auto-feeders began in 2006.  Newer models marketed by the Inteqc Group have improved performance and are growing in popularity.  As many as 50% of Thai farmers are now using auto-feeders and expectations are that most farmers will be using them within two years.

 

Feeders are placed 80+ centimeters above the surface of the pond and 15+ meters from pond bank over deep water, where they don’t overlap with aerators or the central settling zone.  Each feeder holds up to 140 kilograms of feed and can handle the feeding of 700,000 shrimp.  Farms begin using auto-feeding at day 20-25.  Additional feeders are added for ponds stocked above 700,000 shrimp.  Feed is applied 24 hours per day, typically for 1.5 seconds of a minute and repeated continuously.

 

Benefits of auto-feeders:

 

• Feed conversion ratios drop by as much as 30%, to 1.1 to 1.2

• Faster growth and better size uniformity

• Better water quality

• Lower of production costs

• Fresher feed because of continuous feeding

• Minimal leaching

• Feed requires less binder, less wheat, less attractant

• Feed and labor costs are reduced

• Shrimp appear to be feeding in the water column with little feed settling

to the pond bottom

 

Information: Brian Hunter, Diamond V, Asia Business Unit Office, 5th Floor, Pricha Building, 2533 Sukhumvit Road, Bangchack, Prakhanong, Bangkok, Thailand 10260 (phone +66-2730-3248, fax +66-2332-8659, email bhunter962001@yahoo.com, webpage http://www.diamondv.com/company-home).

 

Sources: 1. Email to Shrimp News International from Brian Hunter on December 7, 2011.2. Bob Rosenberry, Shrimp News International, December 13, 2011.

 

Print This Page
HomePrevious PageSite MapTop