The Tissue Residual Analytical Study of Doxycycline in Taiwan Native Chicken and Broiler

• Main Authors: Wan-Chang Tao, 陶萬彰
• Other Authors: 陳德勛
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/23372828505019111123

碩士 === 國立中興大學 === 微生物暨公共衛生學研究所 === 99 === In this study we performed tissue residue analyses of Doxycycline, which are administered orally as powder formulae at a single dose of 20 mg/kg/day for consecutive 5 days on healthy broiler chickens and Taiwan native chickens, respectively. Tissue samples from 9 various sites, including the brain, heart, liver, gizzard, kidney, breast muscles, blood, bone morrow and thigh muscles were collected 12 hrs after Doxycycline withdrawal initially and then sampled every 24 hours for 5 days, concentrations of Doxycycline in these samples were measured, following the standardized procedures declared on 01-04-2004 by Food and Drug Administration(FDA), Department of Health, Executive Yuan. The results reveal that, after oral administration of Doxyclcline at 20 mg/kg/day dose for 5 consecutive days, in both groups the tissue residue levels in liver and kidney recorded 12 hours after withdrawal were consistently higher than blood serum and those in brain, heart, gizzard, breast muscle, bone morrow and thigh muscles were lower than plasma level. The results of the sampling time points measured tissue Doxyclcline concentration, the concentration of the more common higher doxycycline tissue concentration in Broiler chicken than Taiwan native chicken. After withdrawal, tissue residual level of Doxycycline are observed to decline rapidly: for the first 3 days, those in brain, liver, kidney and bone morrow remained higher than serum level, yet on the fifth days after withdrawal only liver and bone morrow have detectable residues. In our study, although 5 days after withdrawal tissue residues in liver and bone morrow remained detectable, those in brain, heart, muscular stomach, kidney, blood and thigh muscles of both broiler and Taiwan native chickens have declined to a barely detectable level 3-4 days after its withdrawal, thus current regulation for a 5-day withdrawal is feasible from the viewpoint of public health concern. In the “Manual of animal drug use”, published by Bureau of Animal and Plant Health Inspection and Quarantine, the use of Doxycycline is permitted in animal husbandry, yet in the”Criteria of animal drug residue”, Department of Health dictates no detectable residual Doxycycline for nearly all kinds of meat products on the market, with the exception of fish, of which the accepted concentration is 0.01 ppm in muscle tissue (amended on 03-17-2008). Because of its broad antibacterial spectrum, low price and convenience to apply, Doxycycline is extensively used in animal husbandry, and the ensuing problems of drug residue deserve attention.