Thoughts and recommendations on metaphylaxis in commercial feedyard settings with an emphasis on drug selection and postmetaphylaxis intervals

Various antimicrobial drugs are approved for metaphylaxis in cattle at high risk for developing BRD. Although many can be used successfully, some antimicrobials appear to have superior comparative effectiveness across a broad range of BRD risk lev­els. Practitioners should familiarize themselves with the avail­able literature to understand which antimicrobial(s) best meet the needs of their clients and the cattle they manage. Once a practitioner has selected an antimicrobial for metaphylaxis purposes, it is also recommended they familiarize themselves with the literature pertaining to post-metaphylaxis intervals (PMI). In general, extending PMI beyond what is tradition­ally regarded as prudent, results in reduced BRD treatments without deleterious effects on BRD mortality or growth perfor­mance. Additional considerations in selecting metaphylaxis agents and PMIs are discussed herein.