Putting research to the test: Implementing selective dry cow therapy on farms across New York State

Abstract

Selective dry cow therapy (SDCT) has been shown to be an ef­fective way of using antimicrobials judiciously on dairy farms while decreasing treatment costs and maintaining herd health. However, adoption of the practice has been slow in the U.S. In order to improve the adoption of this practice in New York State, we formed a team of veterinarians to help interested dairy producers and their herd veterinarians to implement SDCT successfully. Not all farms are a good fit for SDCT. An in-depth discussion between the herd veterinarian and farm stakeholders before adoption is necessary. This discussion should include current practices, data available to make the selection process, best practices for dry off and dry-pen man­agement, and how to monitor progress going forward. Our team enrolled 24 farms over the course of a year. Seventeen out of 24 farms are still using SDCT at the time of publishing. A variety of SDCT methods were used, and on average, herds decreased dry cow antibiotic use by 53%. The metrics we used to monitor herd infection dynamics before and after SDCT included aver­age monthly somatic cell count, fresh cow mastitis incidence, average herd prevalence of a high first test, average herd preva­lence of subclinical infection, average new infection risk, and cure risk. For all but a few herds, 95% confidence intervals overlapped for all outcomes before and after starting SDCT and differences were relatively small. In our experience, SDCT, if employed on the right farm, is an effective way to use antibiot­ics judiciously at dry off without disrupting herd health.