tailieunhanh - Evaluation of reducing shrimp feed in culture of white leg shrimp (Litopenaeus vannamei) using biofloc technology

The study was conducted from 2013 December – 2014 February at the wetlab in College of Aquacultire and Fisheries, Can Tho University. A 2-month feeding trial was carried out to evaluate the ability of using biofloc to reduce shrimp feed in PL of whiteleg shrimp (Litopenaeus vannamei). | Journal of Fisheries science and Technology Special issue - 2015 EVALUATION OF REDUCING SHRIMP FEED IN CULTURE OF WHITE LEG SHRIMP (LITOPENAEUS VANNAMEI) USING BIOFLOC TECHNOLOGY Ta Van Phuong1,2, Nguyen Van Hoa 2, Nguyen Van Ba1 ABSTRACT The study was conducted from 2013 December – 2014 February at the wetlab in College of Aquacultire and Fisheries, Can Tho University. A 2-month feeding trial was carried out to evaluate the ability of using biofloc to reduce shrimp feed in PL of whiteleg shrimp (Litopenaeus vannamei). Trial included six treatments in triplicate: in three treatments without rice-flour addition named 60CT, 80CT and 100CT, shrimp were fed at ratio of 60%, 80%, 100% (control) of daily feeding amount (four times daily), respectively; other three treatments (named 60RF, 80RF, and 100RF) shrimp was fed at the same ratio with the supplement of rice-flour at the Carbohydrate: Nitrogen ratio of 15:1. Used shrimp feed containing 40-42% CP. Rice-flour (RF) was added into culture system to stimulate the microbial biofloc growth. Thirty eight shrimps were randomly distributed into 18 composite tanks of 500L capacity. The results show that Alkality, Turbility, TSS (Total suspended solid), VSS (Volatile Suspended Solid), FVI (Floc Volume Index), Zooplankton, Total bacteria count, and biofloc particle size were higher in treatments with rice-flour supplement (60RF, 80RF, and 100RF). In contrast, (NO2-), Phytoplankton, Total Vibrio count were higher in treatment without rice-flour supplement (60CT, 80CT, and 100CT). Shrimps from treatment 80RF performed highest growth rate () and yield ( kg/m3). The results indicated that the supplement of rice-flour at the Carbohydrate: Nitrogen ratio of 15:1 can help reduce 20% of shrimp feed (treatment 80RF). Keyword: Rice-flour, Biofloc technology, reducing shrimp feed, whiteleg shrimp, C:N ratio. I. INTRODUCTION Brackish water shrimp (Penaeus monodon) farming has been developed for a long time in Vietnam in .