Control of bovine respiratory disease, with and without co-morbidity by otitis media, in dairy heifers comparing gamithromycin, tulathromycin, or no medication at a commercial development facility

摘要

The objective of this study was to evaluate one strategyfor control (metaphylaxis) of bovine respiratory disease,with and without co-morbidity with otitis media,in dairy heifers at a commercial development facility.Individual heifers were the experimental unit. At weaning,1 of 3 experimental treatments (gamithromycin, tulathromycin,or no medication) was randomly assignedto 1,567 heifers from 11 different dairies. Gamithromycinwas administered to 631 heifers, tulathromycinwas administered to 621 heifers, and no medication wasadministered to 315 heifers (negative control). Heiferswere then commingled and penned according to bodyweight. Each pen contained heifers from each group,and periodically, larger numbers of heifers were pennedtogether. All heifers were observed for the subsequent42 d and treated according to protocols prescribed forthe facility. Morbidity due to respiratory disease wasless for heifers medicated with gamithromycin than forheifers medicated with tulathromycin. Morbidity due torespiratory disease was less for heifers medicated withgamithromycin than for heifers in the negative controlgroup. Fewer heifers medicated with either antimicrobialwere subsequently treated because of co-morbiditywith otitis media. Mortality was not different amongthe treatment groups. Heifers medicated with eitherantimicrobial had greater average daily gain than didheifers in the negative control group.