An Evaluation of Concomitant Therapy for the Treatment of Arrival Fever in Feedlot Calves at Ultra-High Risk of Developing Undifferentiated Fever/Bovine Respiratory Disease

摘要

A field study was conducted at four commercial feedlots in the United States to compare the relative efficacy of two treatment programs for the treatment of arrival fever (AF) in feedlot calves at ultra-high risk (UHR) of developing undifferentiated fever/bovine respiratory disease (BRD): concomitant Excede? Sterile Suspension for Cattle (Zoetis, Parsippany, New Jersey) and Draxxin? (Zoetis) (CT) versus Resflor Gold? (Merck Animal Health, Intervet Inc., Madison, New Jersey) (RESF). In this study, 1126 animals with AF were randomly allocated to experimental group and followed from allocation until exit from the feedlot, with the individual animal as the experimental unit. The first AF relapse, second AF relapse, and overall chronicity rates were reduced in the CT group as compared to the RESF group (absolute differences of 15.28%, P < 0.001; 6.52%, P = 0.011; and 0.36%, P <0.001; respectively). In addition, the overall mortality, BRD mortality, metabolic mortality, and other causes mortality rates were lower in the CT group as compared to the RESF group (absolute differences of 9.59%, 6.75%, 0.71%, and 1.42%, respectively; P < 0.001). Average daily gain (allocation to 120 days on trial) was higher in the CT group as compared to the RESF group (difference 10.29%, P < 0.001). In summary, this commercial field trial conducted in UHR calves demonstrated that concomitant administration of Draxxin and Excede for the treatment of initial AF cases was shown to substantially reduce morbidity and mortality (approximately a 50% reduction in overall mortality to feedlot exit), which has meaningful positive impacts on animal welfare