This summary provides preliminary data regarding dry matter content and environmental mastitis pathogen counts in separated manure solids at the new ISU Dairy. Animals were moved to the new dairy on Nov. 26-27, 2007 and manure solid separating was initiated on Nov. 29. Manure solids are separated using a Vincent KP-10 screw press separator. Manure solids dry matter content ranged from 27- 39%. On days where DM% was 27-30%, issues with the separator and system led to enhanced liquid flow into the materials. DM % of 35-40% will be targeted for bedding solids. Total bacteria counts ranged from 10⁶ -10 ⁸ , with alpha streptococci ranging from 10 ⁵ -10 ⁸ . Total gram negatives ranged from <10 ² -10 ⁷ with coliforms ranging from <10 ² -10 ⁴ . Pooled samples are also being tested for presence of Salmonella and Mycobacterium paratuberculosis (Johne’s). Refinement of the separation system and further characterization and standardization of manure solids will take place before use as freestall bedding material.