A 100-Year Review: Lactating dairy cattle housing management
Bewley, J. M., L. M. Robertson, and E. Eckelkamp.  2017.  Journal of Dairy Science, 100(12), 10418-10431.

The objective of this study was to assess differences between compost bedded pack (CBP) and sand freestall barns (SFB) for mastitis indicators (herd clinical mastitis, SCC, high SCC prevalence (% of herd ≥200,000 cells/mL SCC), and BTSCC), and locomotion, hygiene, and hock scores. This study was conducted on commercial Kentucky dairy farms using CBP (n=8) or SFB (n=7) as the primary lactating cow housing facility from May 2013 to May 2014. To indicate good management practices, eligible herds had to maintain a yearly mean SCC <300,000 the year before enrollment in the study. Milk samples were collected from quarters that presented clinical signs of mastitis as identified by milking personnel. Each herd was visited biweekly (n=26 visits) over the study period. Each visit included evaluating 50 cows per herd for hygiene, locomotion, and hock scores. Somatic cell count (SCC) and high SCC prevalence (percentage of animals in each herd with a test day SCC ≥200,000 cells/mL) were collected from Dairy Herd Information Association (DHI, Raleigh, NC). Bulk tank SCC from each pick up was gathered from each dairy's milk purchaser. Bulk tank SCC from each pick up for all Kentucky herds on DHI regardless of SCC or housing type from January 20132014 was requested from the Kentucky Milk Quality Safety Branch to determine differences among all bedding types without selecting for herds enrolled in DHI. Overall, no differences between 8 CBP and 7 SFB selected based on SCC existed for herd locomotion, hygiene, or hock health. No differences were observed for the main effects of housing, maximum temperature humidity index, or hygiene score on SCC, high SCC prevalence, clinical mastitis incidence, or bulk tank SCC for 8 CBP and 7 SFB Kentucky herds. Similarly, for Kentucky DHI herds, bulk tank SCC was not different among herds using CBP, freestall barns, and tie-stall barns. Herds using CBP alongside freestall barns had the lowest bulk tank SCC in Kentucky. These results indicate that, when managed properly, CBP can provide a housing environment comparable to SFB. Freestalls, tie-stalls, and compost bedded pack barns for all herds on DHI had similar bulk tank SCC.