THE AVAILABILITY OF TETRACYCLINES IN CALVES

  • 1 January 1983
    • journal article
    • research article
    • Vol. 35  (7-9) , 292-299
Abstract
The bioavailability of oxytetracycline (OTC) and chlortetracycline (CTC) was studied in non-fasting calves. The availability of OTC was 5% and of CTC 37% after oral administration of 10 mg/kg. The area under the curve (AUG) was reduced 68% when OTC was given in milk replacer; reduced CTC availability was reduced 40%. When given in milk, the reduction was 72% for OTC and 47% for CTC. Ca and Fe caused a dramatic reduction of serum levels. OTC was stored mixed in milk powder at room temperature for 6 mo. without loss in availability. OTC did not chelate Ca2+ in serum. Thus, CTC is more suitable than CTC for oral therapy in calves.