Effects of Activate DA on Growth, Survival and theTotal Number of Bacteria and Vibrio spp. in Rearing of Pacific White Shrimp (Litopenaeus vannamei)

Abstract

A study on the effects of activate DA on growth and survival of Pacific white shrimp (Litopenaeus vannamei) was conducted under laboratory conditions. Tests were carried out in seven treatments (with five replicates/treatment). Post larvae 12 (PL12) were stocked into 500-liter fiberglass tanks at a density of 50 PL/tank. Salinity during the experimentation period was 25 ppt. Shrimp were fed four times daily with pelleted feed containing activate DA at different levels, namely 0.1, 0.2, 0.4, 0.8, 1.2 and 1.6%, and a control treatment which did not contain activate DA. After 60 days of dietary administration, shrimp fed with 1.2% of activate DA had an average body weight of 6.87+ 0.27g, which was not significantly higher (P>0.05) than those of shrimp fed with 1.6% (6.47+0.24g) of activate DA. However it was significantly higher (P<0.05) than the control group (5.14+0.76g) and the other treatments with 0.1% (4.61+0.47g), 0.2% (5.10+0.13g), 0.4% (5.42+0.24g) and 0.8% (5.92+1.04g) of activate DA. Shrimp fed with 1.2% of activate DA had the highest survival rate at 95.60 + 3.58 %, followed by those fed with 1.6% (92.00+2.83%), 0.8% (88.40+2.61%), 0.4% (87.20 +4.60%), 0.2% (80.40+1.67%) and 0.1% (78.80+5.02%) of activate DA. Shrimp in the control group had the lowest survival at 67.20 + 6.73%. Total bacterial and total Vibrio spp. counts in the intestines of shrimp fed with 1.2% of activate DA were 5.48+1.74 x 10² CFU/g and 2.90 +0.85 x 10² CFU/g, respectively.