Comparison of treatment protocols for bovine respiratory disease in high-risk, newly received beef calves

Abstract

Objective: This research evaluated the effects of different antibiotic treatment protocols on performance, morbidity, antibiotic usage, and cost in high-risk, newly received beef calves. Materials and Methods: Crossbred male calves (n = 176; BW = 232 ± 1.6 kg) were stratified by BW and castration status and assigned randomly to 1 of 2 treatments in a randomized complete block design. Calves were administered either 2.5 mg/kg of BW of tulathromycin (TUL, Draxxin, Zoetis, Florham Park, NJ) with a 7-d post-metaphylactic treatment or 10 mg/kg of BW of tilmicosin (TIL, Micotil, Elanco Animal Health, Greenfield, IN) with a 1-d post-metaphylactic treatment. Clinical attitude scores [0 (normal) to 4 (moribund)] were assigned daily to assess morbidity and when ≥ 1, and if rectal temperature exceeded 40°C, an antibiotic was administered per preplanned protocol. Calves that received TUL on d 0 received ceftiofur with a 7-d post-treatment interval, and those that received TIL received enrofloxacin with a 3-d post-treatment interval. A final antibiotic was administered to calves that were pulled a second time and met the treatment criteria. Results and Discussion: Percentage morbidity was greater for the first treatment, the second treatment, and relapse in TIL compared with TUL (P < 0.0001). Initial antibiotic cost was greater in calves administered TUL compared with TIL (P < 0.0001). Both first- and second-treatment antibiotic costs were greater in TIL compared with TUL (P ≤ 0.0003). However, there were no differences across treatments in overall antibiotic cost (P = 0.51), exclusive of labor or chute charges. Implications and Applications: Metaphylactic treatment protocols did not affect growth performance, but differences were found in the percentage of calves treated for clinical bovine respiratory disease and in number of antibiotics used.