Authors : C. Duff , B. D. Hunsaker , A. C. Anderson , J. D. Roder and D. W. Walker
Abstract: Eighteen beef steers (British x Continental; average bW at sampling 329kg) were used to evalute effects of added dietary fat (yello grease) concentration on serum and lung lavage sample concentrations of florfenciol. Steers were assigned randomly to dietary fat concentrations and were housed in individual pens. Treatments were a 70% concentrate diet with 0% added fat (6 steers), 3% added fat (6 steers), and 6% added fat (6 steers). Steers were fed at approximately 2.25% (as-fed absis) of BW for 3 wk before sampling. Florfenicol (Nuflor; Schering-Plough Anim. Health) was administered s.c. at 40 mg/kg of BW in the neck. Serum and lung lavage samples were collected at 0, 6, 12, 24 48 and 72 h after administration of florfenicol. Concentrations of florfenicol in lung lavage fluid an dcells were non-detectable. In serum. In serum, no florfenicol concentrations were observed at 0 h. At 6 h, a quadratic (P<0.05) response was observed with highest concentrations of florfenicol observed with the 3% added fat. No. differences (P>0.10) were observed at 12 h. At 24 h, however, a linear (P<0.05) increase in florfenicol concentration was noted with added dietary fat. No differences (P>0.10) were observed at 48 or 72 h. Results suggest that added dietary fat influences serum concentrations of florfenicol. Hoever, methods more sensitive to small antibiotic concentrations need to be conducted to evaluate the effects of dietary fat on host tissue concentrations.
C. Duff , B. D. Hunsaker , A. C. Anderson , J. D. Roder and D. W. Walker , 2003. Florfenicol Concentration in Serum of Beef Cattle Fed 0, 3 or 6% Added Dietary Fat in a 70% Concentrate Diet. Journal of Animal and Veterinary Advances, 2: 44-48.