Effects of pathogen-specific clinical mastitis occurrence in the first 100 days of lactation 1 on future mastitis occurrence in Holstein dairy cows: An observational study

The objective of this observational study was to estimate effects clinical mastitis (CM) cases caused by different pathogens (Streptococcus spp., Staphylococcus aureus, Escherichia coli, Klebsiella and CM with no growth) occurring in the first 100 d lactation 1, a dairy cow on future rate occurrence types during cow's full lifetime. outcomes were Streptococcus growth, after until removal through death or sale that subsequent lactation. Data, including information cases, milk production, event dates (including dates), collected from 14,440 cows 5 New York State Holstein herds January 2004 February 2014. Generalized linear mixed models Poisson distribution log link function fit for each pathogen. individual unit analysis. coli predictor E. growth. Early-occurring spp. Cases growth predictors Thus, early 1 appear be consistent risk factors CM, whether same pathogen In study, farm later differed somewhat, so treatment protocol culling strategy may play role findings. Nevertheless, findings help farmers managing young productive life, especially those they more susceptible their thus meriting closer attention.