title: Short communication: Drug residues in goat milk after prophylactic use of antibiotics in intravaginal sponges for estrus synchronization.
abstract: The aim of this study was to determine whether the prophylactic use of antibiotics in intravaginal sponges used for estrus synchronization in goats may result in the presence of inhibitors in milk and, therefore, of positive results by microbial screening tests. Ninety-eight Murciano-Granadina goats were used, divided into 7 groups of 14 animals. Intravaginal sponges were placed in 6 groups using 2 concentrations of 3 different antibiotics: doxycycline, oxytetracycline, and sulfathiazole-framycetin. The sponges of the control group were placed without antibiotics. Milk samples were collected daily until 7 d posttreatment and analyzed using 3 microbial tests. Positive samples were retested by specific receptor-binding assays to confirm the positive results. Vaginal status was evaluated by visual assessment of the external aspect of the sponges after removal. The microbial test response was not affected by either day posttreatment or dose of antibiotic used, except for oxytetracycline at the higher concentration. Moreover, no positive results were obtained using receptor-binding assays, suggesting that residues, if present in milk, did not exceed the regulatory (safety) levels established for these drugs. The occurrence of soiled sponges was higher in the control group. With respect to the dose of antibiotics used, no significant differences were found for the lower dose administered. However, a significant increase in the percentage of clean sponges was observed for the higher dose of doxycycline. We conclude that the prophylactic use of low doses of doxycycline, oxytetracycline, or sulfathiazole in intravaginal sponges used for synchronization of estrus helps to reduce clinical vaginitis in dairy goats and does not seem to be the cause of positive results in microbial inhibitor tests used to detect antibiotics in goat milk.
authors.affiliation: Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, 46022 Valencia, Spain. Electronic address: tarorue@upvnet.upv.es.
authors.forename: T
authors.initials: T
authors.lastname: Romero
authors.affiliation: Granja Experimental Diputación Provincial de Castellón, Castellón, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Balado
authors.affiliation: Cátedra de Biofísica. Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, 3080 Esperanza, Argentina.
authors.forename: R L
authors.initials: RL
authors.lastname: Althaus
authors.affiliation: Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, 46022 Valencia, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Beltrán
authors.affiliation: Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, 46022 Valencia, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Molina
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D003274:Contraceptive Devices, Female; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000032:analysis; D004350:Drug Residues / Q000032:analysis*; D004973:Estrus Synchronization / Q000187:drug effects*; D005260:Female; D005601:Framycetin / Q000032:analysis; D006041:Goats; D057230:Limit of Detection; D016015:Logistic Models; D008892:Milk / Q000737:chemistry*; D010118:Oxytetracycline / Q000032:analysis; D013432:Sulfathiazoles / Q000032:analysis; D014621:Vagina
chemical_list: D000900:Anti-Bacterial Agents; D013432:Sulfathiazoles; D005601:Framycetin; D004318:Doxycycline; D010118:Oxytetracycline
keywords: antibiotic screening methods; goat milk; intravaginal sponge