title: Short communication: Determination of withdrawal time for oxytetracycline in different types of goats for milk consumption.
abstract: Antibiotics are widely used in animal husbandry and the presence of antibiotics in milk is a health hazard. The objective of this study was to determine residual amounts of oxytetracycline in fresh, aged, and pasteurized milk of 3 breeds of goats using HPLC analysis. It was also essential to determine the safe withdrawal period of oxytetracycline in lactating goats. The quantitative results obtained using the HPLC system were compared with the tolerance limit of oxytetracycline in milk in the United States. Fifteen milking does, 5 Nubians, 5 Alpines, and 5 LaManchas were randomly selected from the milking herd at the International Goat Research Center at Prairie View A&M University. A simple sample preparation and isocratic HPLC method using ultraviolet detection was used for analysis of milk samples. The HPLC results indicated that the withdrawal period of oxytetracycline in treated Alpine does was 82h (7 milking), whereas for Nubian does the period was 58h (5 milking), and for LaManchas the period was 72h (6 milking) after drug administration. The overall withdrawal period for all the treated goats of 3 breeds was 72h. Although these results indicated that the depletion rate of this antibiotic was faster in goats than the reported data for cows, the 96-h withdrawal period that is currently used for lactating cows is still necessary for these 3 breeds of goats. Additionally, our results indicated that oxytetracycline is not stable in goat milk at refrigeration temperature or during pasteurization and will decrease significantly.
authors.affiliation: Prairie View A&M University Cooperative Agricultural Research Center, Prairie View, TX 77446. Electronic address: rattaie@pvamu.edu.
authors.forename: Rahmat
authors.initials: R
authors.lastname: Attaie
authors.affiliation: Prairie View A&M University Cooperative Agricultural Research Center, Prairie View, TX 77446.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Bsharat
authors.affiliation: Prairie View A&M University Cooperative Agricultural Research Center, Prairie View, TX 77446.
authors.forename: Adela
authors.initials: A
authors.lastname: Mora-Gutierrez
authors.affiliation: Prairie View A&M University Cooperative Agricultural Research Center, Prairie View, TX 77446.
authors.forename: Sela
authors.initials: S
authors.lastname: Woldesenbet
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D004350:Drug Residues / Q000032:analysis*; D005260:Female; D006041:Goats / Q000235:genetics; D007774:Lactation; D008892:Milk / Q000737:chemistry*; D010118:Oxytetracycline / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D000900:Anti-Bacterial Agents; D010118:Oxytetracycline
keywords: goat milk; oxytetracycline; residues; withdrawal period