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Discussion in 'Emergencies / Diseases / Injuries and Cures' started by ironsfamilyfarm, Jan 8, 2015.
It means nothing...
Withdrawal times of oxytetracycline and tylosin in eggs of laying hens after oral administration.
Muñoz R1, Cornejo J2, Maddaleno A1, Araya-Jordán C1, Iragüen D1, Pizarro N1, San Martín B3.
Antimicrobials administered to laying hens may be distributed into egg white or yolk, indicating the importance of evaluating withdrawal times (WDTs) of the pharmaceutical formulations. In the present study, oxytetracycline and tylosin's WDTs were estimated. The concentration and depletion of these molecules in eggs were linked to their pharmacokinetic and physicochemical properties. Twenty-seven Leghorn hens were used: 12 treated with oxytetracycline, 12 treated with tylosin, and 3 remained as an untreated control group. After completion of therapies, eggs were collected daily and drug concentrations in egg white and yolk were assessed. The yolk was used as the target tissue to evaluate the WDT; the results were 9 and 3 days for oxytetracycline and tylosin, respectively. In particular, oxytetracycline has a good oral bioavailability, a moderate apparent volume of distribution, a molecular weight of 460 g/mol, and is lightly liposoluble. Tylosin, a hydrosoluble compound, with a molecular weight of 916 g/mol, has a low oral bioavailability and a low apparent volume of distribution, too. Present results suggest that the WDTs of the studied antimicrobials are strongly influenced by their oral bioavailability, the distribution, and the molecular weight and solubility, and that these properties also influence the distribution between the egg yolk and white.
My best guess would be no less than two weeks for the injectable.
Post #52 has been edited.
Reed this link it is from the FDA sight reed page 6.
"...Withdrawal Times: Because a waiver of the in vivo bioequivalence study was
granted, the withdrawal times are those previously assigned to the pioneer product.
o Chickens must not be slaughtered for food within 24 hours after treatment. Do not use in layers producing eggs for human consumption...."
If the FDA don mean nothing I don't know who does!
1 the FDA is the most objective regulator of your country not mine, if you don't believe it I don't know what to say.
2. To understand all the mechanisms of residence to antibiotics learn about plasmids, transformation, conjugation,transductions and the gene transferring in bacteria and you will know why the makes their regulation!