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 ที่มา:KASETSART UNIVERSITY FISHERIES RESEARCH BULLETINหัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : A Comparison Study on Production and Plankton between Two Water Exchange Rates of Recirculating Shrimp Culture (Penaeus monodon) System Using Low Salinity Water) ผู้เขียน: Tanyanan Kaweekityota,  ดร.วราห์ เทพาหุดี, รองศาสตราจารย์ , ดร.ชลอ ลิ้มสุวรรณ, รองศาสตราจารย์ , ดร.นิติ ชูเชิด, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractA recirculating shrimp culture system was studied at a commercial shrimp farm in Thailand. Low salinity water was used for supply in the farm. Four experimental ponds were employed. Postlarvae 15 (PL 15) were stocked at a density of 44 PL/m2. After 60 days of culture, two water exchange rates (i.e. 10% of pond water volume, once and twice a week) were tested. The system production from low percentage water exchange rate was 824?96.2 kg/rai, average weight of 20.9?1.84 g, The production from high percentage water exchange rate was 876+46.0 kg/rai, average weight of 23.4 ?2.33 g, growth rate of 0.17?0.05g, survival rate of 56.4?1.2 % and FCR of 1.55 ?0.06. growth rate of 0.15?0.064 g/day, survival rate of 56.3?1.6 % and FCR of 1.55?0.06. However, there was not a statistically significant difference. Most water quality parameters were in an acceptable range. A large number of blue-green algae were often found during the culture period. Results show that the water exchange rate of 10% once a week could obtain acceptable production results, which was not a statistically significant difference from the other rate. Therefore shrimp culture in recirculating systems using low salinity water with water exchange starting 60 days after culture, using 10% of pond water volume every week, was found acceptable. |
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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Applications of Paddle Wheel Aerators and Diffused-Air System in Closed Cycle Shrimp Farm System) ผู้เขียน:ดร.วราห์ เทพาหุดี, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractShrimp culture practices are changing from high water exchange systems to low water exchange systems to reduce the risk of disease contamination and water pollution. The low water exchange systems require a great number of aerators to prevent water deterioration due to high organic loading associated with limited water exchange. However, high rates of aeration can not only cause excessive water currents and erode pond bottom badly but also increase power cost. In this present study, applications of paddle wheel aerators and diffused-air systems were investigated in grow-out ponds of a closed cycle farm. The results showed that these systems were successful used in shrimp production, and of the systems examined, a combination of paddle wheel and medium bubble size diffused-air system, with a polyethylene pipe network proved to be most effective and convenient. This aeration system provided suitable dissolved oxygen concentrations to the water body and the pond bottom, which could stimulate decomposition at the pond bottom. In addition, this system had low operating costs. It is suitable to be applied in low water exchange culture systems and it can also reduce problems of pond bottom erosion, a typical problem, when using large numbers of paddlewheels. |
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