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Establishment of zero-water exchange cultivation technology in the white shrimp, Litopenaeus vannameiChang, Chun-ming 13 July 2005 (has links)
White shrimp (Litopenaeus vannamei) were cultured in isolated environment using zero-water exchange to investigate optimum cultivation method. Except density experiment, culture density was 100 shrimps/m2 in all other experiments. The results indicated that simple quarantine facility could prevent virus infection of pond shrimps. After 83 days of cultivation, survival rate, final weight, yield and growth rate (90.7%, 16.8 g, 1.52 kg/m2, 1.36 g/week) of zero-water exchange group was not significantly different from those of water exchange group, but FCR was lower (p<0.05) instead. Addition of brown sugar increased final weight and growth rate of shrimp and lowered FCR (18.6 g, 1.60 kg/m2, 1.64 ¡Ó 0.04) (p<0.05), but nitrification was inhibited. Application of two mats per tank gave highest increases in final weight and yield and lowest FCR (p<0.05). Bottom sand increased final weight and yield and lowered FCR (p<0.05), stabilized pH and increased de-nitrification efficiency. Salinity of 25 ppt had highest final weight and yield and lowest FCR (p<0.05). Density of 200 shrimps/m2 had highest final weight and lowest FCR (p<0.05) and yield twice as that of density of 100 shrimps/m2. At the end of cultivation, water quality condition between 37% and 32% protein feed were not significantly different. But, the shrimps of 37% protein feed had higher final weight, lower FCR (p<0.05) and 26% more yield. The above results indicated that the risk of shrimps infected by virus could be prevented using zero-water exchange culture method. As long as solid was held suspending by sufficient agitating, good water quality could be maintained. Hence, zero-water exchange culture could not only decrease electricity of water pump and quantity of water use, but also increase the value of product and incorporation efficiency of feeds.
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