Treatment Response to Bovine Respiratory Disease in Beef Stocker Calves Was Not Positively Affected When Using Isoflupredone Acetate as Ancillary Therapy
The objective of this study was to evaluate the use of isoflupredone acetate as ancillary therapy in the treatment of bovine respiratory disease in high risk stocker calves. Crossbred male beef calves (n = 192; BW = 221 ± 3.9 kg) were acquired in 2 blocks from regional auction markets and were transported to the University of Arkansas Stocker and Receiving Cattle Unit. Calves were observed daily for signs of respiratory illness, and antibiotic treatment was administered if calves displayed signs of illness and rectal temperature was ≥ 40°C. Calves (n = 72) requiring antibiotic treatment for respiratory illness were assigned randomly to either treatment 1 (injection of florfenicol) or treatment 2 (injection of florfenicol with isoflupredone acetate). Treatments occurred between d 2 and d 14 of the study. Both treatment groups were rechecked 48 h post treatment to determine treatment efficacy. Blood was collected twice (at treatment and recheck) via jugular venipuncture to evaluate complete blood cell count. Body weights were recorded at d 0, 14, 28, and 46 (block 1) or 42 (block 2). No difference was evident between treatment groups for medical treatment cost (P = 0.54) or number of calves requiring a second or third antibiotic treatment (P ≥ 0.61). Upon recheck, neutrophils were higher and lymphocytes were lower in calves that received isoflupredone acetate (P ≤ 0.04) compared to calves that received only antibiotic therapy. Consequently, the neutrophil to lymphocyte ratio was greater (P < 0.01) in calves that received isoflupredone acetate compared to those that only received antibiotic therapy. No difference existed in overall white blood cell count at recheck (P = 0.67) or body temperature at recheck (P = 0.43). Calves that received isoflupredone acetate tended to exhibit greater (P = 0.09) ADG between d 14 and d 28 compared to calves that were treated with only antibiotic therapy, 1.04 kg and 0.77 kg, respectively. Overall ADG for the entire receiving study was similar (P = 0.88) for both treatments. Results indicate that treatment of bovine respiratory disease with isoflupredone acetate as ancillary therapy to an antibiotic regimen does not have a positive effect on overall ADG, and it does not reduce medical treatment cost or the number of repeat treatments.
bovine respiratory disease, ancillary therapy, isoflupredone acetate