The livestock industry has been taking a lot of heat about its use of antibacterial products and the concern that it will lead to antibiotic-resistant bugs. However, a new study, reported in the May issue of the Journal of Dairy Science, shows that, at least with common mastitis pathogens, that’s just not the case.

For seven years, Michigan State University researchers collected milk samples from cows suspected of having mastitis. They identified eight common mastitis pathogens seen on dairies and tested each for antibacterial resistance. Overall, there was no indication of an increase in resistance to antibiotics. And in some cases, with specific pathogens, the bugs had become more susceptible to antibiotics.

One possible explanation for not seeing an increase in resistance to antibiotics, say the authors of the study, may be the “more prudent and conservative use of antibacterial products on dairy farms.”