Hogan, Kellie2013-09-052018-01-292013-01-28bibid: 8267360https://hdl.handle.net/1813/33888The work included in this thesis is focused on research regarding the organic dairy community and milk quality. Our research is dedicated to assessing differences and best management practices on organic and conventional dairy farms throughout New York, Wisconsin and Oregon. We concentrated on modeling management associations with regularly used milk quality indicators somatic cell count, standard plate count, coliform count, as well as the presence of Staphylococcus aureus (S. aureus) in bulk tank milk. We also assessed general differences among conventional non-grazing, conventional grazing and organic dairy farms in the study population. Finally, we assessed the presence of methicillin-resistant S. aureus in bulk tank milk of the study population. As a whole, our results indicated that while the organic dairy community faces many unique management challenges and in achieving optimal milk quality, the factors affecting the organic community are much the same as those affecting the conventional community. An interesting point from our research is that farms that tend to use more outside resources and external inputs tend to have better quality. In addition to this finding, conventional farms are more likely to use external resources than organic farms. Finally, we determined that there is a low prevalence of methicillin-resistant coagulase negative Staphylococcus spp. and S. aureus in the bulk tank milk of both organic and conventional dairies in our study population. Overall, we have found that while both organic and conventional dairy farms, while facing their own individual challenges, are not all that different in the US.en-USOrganic DairyManagementMilk Qualitydissertation or thesis