Comparison of Resflor Gold® (florfenicol and flunixin meglumine) and Baytril® (enrofloxacin) in Treatment of Bovine Respiratory Disease in a California Calf Ranch

Abstract: In February 2010, a randomized, blinded clinical trial to examine the health performance differences between Resflor Gold® (florfenicol and flunixin meglumine) and Baytril® (enrofloxacin) in a California calf ranch was initiated. In this 49-day study, Holstein steers were assessed for BRD in group pens after leaving hutches. A total of 655 animals qualified for the study and were randomly treated with RESFLOR GOLD (n=322) or Baytril (n=333), and both used a 5-day post treatment interval. The overall incidence of BRD in this study was 46% (655/1410). The first treatment success rate 91% (293/322) for RESFLOR GOLD is significant (p<0.0001) to Baytril 79% (262/333) for cattle in this study. There were no mortalities during this 49-day study. This study shows that RESFLOR GOLD (with a 5-day post treatment interval) outperformed Baytril in initial BRD treatment success.

Study Animals

  • 655 Holstein steers were eligible for inclusion
  • Animals weighed 185 - 215 lbs body weight
  • Deemed by study veterinarian to be at high risk for developing BRD
  • All animals were PI-BVD negative

Study Design

  • Timing: Feb. 23 – April 12, 2010
  • Randomized, blinded
  • Natural BRD clinical trial
  • Trial Duration: 49 Days
  • Location: California calf ranch
  • Study done in group pens

Enrollment Criteria

Animals exhibiting clinical signs of BRD were enrolled; in addition, depression and respiratory scores were assigned to each enrollee.

Depression Scores

  • 0 = Normal: Bright, alert and responsive
  • 1 = Mildly depressed
  • 2 = Moderately depressed
  • 3 = Severely depressed

Respiratory Scores

  • 0 = Normal: No abnormal respiratory symptoms
  • 1 = Mild respiratory distress
  • 2 = Moderate respiratory distress
  • 3 = Severe respiratory distress

Treatments and Dosing

The initial treatments for this study were:

  • RESFLOR GOLD: 40 mg/kg florfenicol : 2.2 mg/kg flunixin meglumine (6 mL/cwt), SQ in the neck one time with a 5-day PTI (post treatment interval).
  • Baytril: 11 mg/kg (5 mL/cwt), SQ in the neck one time with a 5-day PTI. The subsequent treatments were the ranch’s standard treatments.

Outcomes

  • Morbidity
  • First treatment success rate
  • Mortality

First Treatment Success Rate for Cattle Treated for BRD with RESFLOR GOLD or Baytril

Results and Discussion

Average Depression and Respiratory Scores at Enrollment

  • Average Depression Scores: Baytril (2.26); RESFLOR GOLD (2.3); p = 0. 29
  • Average Respiratory Score: Baytril (1.79); RESFLOR GOLD (1.83); p = 0.40

Average BRD Incidence (Morbidity)

  • The overall incidence of BRD in the candidate population was 46% (655/1410)
  • The range of BRD within pens was 15% - 93%
  • Overall RESFLOR GOLD treatment group: 322/678 = 47%
  • Overall Baytril treatment group: 333/732 = 45%

Treatment Success (Figure 1)

  • First treatment success rate 91% (293/322) for RESFLOR GOLD is significant (p<0.0001) to Baytril 79% (262/333)

Mortality: There were no mortalities during this 49-day study.

Conclusion
In this field trial RESFLOR GOLD (with a 5-day post treatment interval) outperformed Baytril as a first treatment antibiotic for bovine respiratory disease. There was no significant difference in the average respiratory scores 1.79 (Baytril) and 1.83 (RESFLOR GOLD) or the average depression scores 2.26 (Baytril) and 2.30 (RESFLOR GOLD) of animals enrolled in this study. Following initial antimicrobial treatment, a 5-day post treatment interval (PTI) was observed for all animals. During this time no animal was eligible for retreatment (unless moribund). The first treatment success rate for RESFLOR GOLD was 91%, which is significant (p<0.0001) as compared to a first treatment success rate of 79% for Baytril. This study shows that RESFLOR GOLD (with a 5-day post treatment interval) outperformed Baytril as an initial treatment for bovine respiratory disease.