Residues of oxytetracycline in black tiger shrimp (Penaeus monodon) reared in cement tank and earthen pond
การตกค้างของยาปฏิชีวนะออกซิเตทตร้าซัยคลินในกุ้งกุลาดำ (Penaeus monodon) ที่เลี้ยง ในบ่อซีเมนต์และบ่อดิน

Sopon Onkong, Scientist, Satun Coastal Aquaculture Development Center, Coastal Aquaculture Division, D. of Fisheries, Langu, Satun
Amonrat Sermwatanakul, Ornamental Fish Division, D. of Fisheries, Kaset Klang, Bangkok
Chutima Tantikitti, Asst. Prof., D. of Aquatic Sci., F. of Natural Resources, PSU.
Corresponding e-mail : tachutim@ratree.psu.ac.th
Grant : Government Budget
Published : Songklanakarin J. Sci. Technol. 2000, 22(Suppl.) : 717-724
Key words : black tiger shrimp, oxytetracycline, drug residues

The objective of this experiment was to investigate residual concentration of oxytetracycline (OTC) in different tissues of black tiger shrimp subsequent to treatment with the antibiotic. Three-month-old shrimps weighing 17.54ฑ0.5 g were cultured in 1.2x2.8x0.6 m3 cement tanks or in 0.25 hectare earthen ponds. Three cement tanks each containing 30 shrimps per square meter and two earthen ponds each containing 35 shrimps per square meter were used. Shrimps were fed commercial diet sprayed with OTC (86.4% active ingredient) 5g/kg of diet at the daily feeding rate of 3% of body weight for seven days. The shrimps were then sampled every day for a period of 28 days for the determination of residues of OTC in integument, hepatopancreas, and muscles. These determinations were made using high performance liquid chromatography. For both rearing conditions, the OTC concentration in the hepatopancreas during the medication period was 2 to 3 fold higher compared with the other tissues. The OTC concentration in hepatopancreas decreased from approximately 19 to 2 ppm within 7 days after withdrawal and the tissue was free of any detectable residue at 17 and 14 days after withdrawal in the cement tanks and earthen ponds, respectively. Since the dietary concentration of OTC used in this experiment is the same as that used in commercial farming, a withdrawal period of 21 days appears to be adequate in terms of public health concerns related to residual levels of this antibiotic in the shrimp tissues meant for human consumption.
BACK