A new study conducted by a former food science professor at the University of Wisconsin-Madison shows that milk quality is higher on larger farms in Wisconsin.

The objective of this study was to evaluate possible claims by advocates of small-scale dairy farming that milk from smaller Wisconsin farms is of higher quality than milk from larger Wisconsin Farms. Steve Ingham author of the study says that when farms are grouped according to size, this just wasn’t the case.

Reported bulk tank standard plate count (SPC) and somatic cell count (SCC) test results for Wisconsin dairy farms were obtained for February to December 2008. Farms were sorted into three size categories using available size-tracking criteria: small, large and confined animal feeding operation. Small was defined as less than 118 cows, large was defined as 119–713 cattle, and confined animal feeding operations (CAFO) was defined as greater than 714 cattle.

The average SPC for the CAFO group was 35,000 colony forming units per milliliter or cfu/mL. The average SPC for large farms and small farms was 36,300 cfu/mL and 58,700 cfu/mL, respectively. SCC for the CAFO group was 240,000 and 273,000 for large farms. Small farms averaged at 369,000.

Ingham reasoned that largest operations could have more money to spend on good equipment or have the ability to cull out cows with mastitis more quickly. As a result, the claim of Wisconsin smaller farms producing higher quality milk than Wisconsin larger farms cannot be supported.

This study was published in the August Journal of Dairy Science.