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In the past decade, the demand for organic agricultural products has increased rapidly in the United States and worldwide. Milk quality research is of major interest to both consumers and dairy farmers alike. However, scientific data on milk quality, herd management methods, and animal welfare on organic farms in the United States has been lacking before the research from this study. The objective of this study was to evaluate the association of bulk tank milk somatic cell count (SCC) with management characteristics on organic and conventional dairy farms in New York, Oregon, and Wisconsin. Data from similarly sized organic farms (n=192), conventional nongrazing farms (n=64), and conventional grazing farms (n=36) were collected at a single farm visit. Of the 292 farms visited, 290 bulk tank milk samples were collected. Overall, no difference in SCC was observed between the conventional and organic grazing systems. Two models were created to assess the effects of various management and herd characteristics on the logarithmic transformation of the SCC (LSCC), one using data from all herds and one using data from organic herds only. From the total herd model, more grain fed per cow per day was negatively associated with LSCC, whereas a positive bulk tank culture for Staphylococcus aureus and years that a farmer reported being in the dairy business were both positively associated with LSCC. In the organic herd model, a seasonal effect indicated that LSCC tended to increase in the summer and decrease in the winter. Grain fed per cow per day, the use of anionic salts in transition-cow diets, the use of gloves during milking, and regular use of a quarantine unit at milking were all negatively associated with LSCC. Similar to the total herd model, a Staph. aureus-positive bulk tank culture was positively associated with LSCC in the organic model. Standard plate count was also positively associated with LSCC in the organic model. Several variables that were associated with management using external resources were combined to create an external input score. In the total herd model, use of more external resources was negatively associated with LSCC. Conventional herds in the study tended to use more outside management resources than organic herds., (Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to evaluate management characteristics on organic and similarly sized conventional dairy farms located in New York, Wisconsin, and Oregon. Data from 192 organic farms (ORG), 64 conventional nongrazing farms (CON-NG), and 36 conventional grazing farms (CON-GR) were collected during farm visits and were size-matched and analyzed. The average lactation number of animals on ORG and CON-GR farms was 2.6 lactations, which was greater than that on CON-NG farms (2.3 lactations). A greater percentage of first-lactation heifers were found on conventional farms than on ORG farms. Facilities used by adult animals, including housing and milking facilities, did not differ among the grazing systems. Cattle on conventional farms were fed approximately twice as much grain as cattle on ORG farms and had greater milk production. Little difference was found for the average reported somatic cell count and standard plate count, suggesting that milk quality is not dependent on grazing system. Milking procedures were similar across all 3 grazing systems, indicating that an industry standard now exists for milking and that milk quality problems will need to be addressed with other management problems in mind. Although some disease prevention measures were commonly utilized on ORG farms, such as keeping a closed herd and having a written record of treatments administered to the animals, the use of outside support and vaccinations were found to be less prevalent on organic farms than on conventional farms., (Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)