A UW-Madison study has found that milk produced on Wisconsin's large farms, including the controversial industrial-size operations, is often of higher quality than milk from smaller farms.

Steve Ingham, who led the study while working as a UW-Madison food science professor, speculated that the bigger farms may have more money to spend on equipment or may be better able to identify and remove cows with illnesses that affect milk production, such as mastitis.

Ingham, who is now the food safety division administrator at the Wisconsin Department of Agriculture, Trade and Consumer Protection, added that all of the state's farms, whether large or small, produce milk that easily meets federal food safety guidelines.

A spokesman for the Wisconsin Farmers Union, a group that represents the state's small farmers, questioned some aspects of the study and said that concerns about the industrial farms go beyond milk quality to issues such as water pollution.

Ingham said no funding for the study was necessary because it used existing data from state and federal government inspections. He said he conducted the study because of a common perception that milk quality is higher on Wisconsin's smaller farms.

"I'd heard a lot of comment about milk from small farms being better," said Ingham. "And I was curious."

Ingham used two measurements related to milk quality to evaluate farms. He gathered information on standard plate counts, which measure bacteria, and somatic cell count, which measure infection in cows. Both measurements, Ingham said, also provide some insight into both the quality of a farm's milk handling, including refrigeration, and disease prevention.

For his analysis, Ingham divided the state's farms into three size categories. He studied data from 12,866 small farms with 118 cows or less, 1,565 larger farms with 119 to 713 cows, and 160 industrial farms, also known as confined-animal feeding operations, or CAFOs, with more than 714 cows.

Ingham found that the CAFOs in the study had the lowest mean milk quality scores for both bacteria and infection levels. Large farms had the next lowest and the small farms ranked third.

Tom Quinn, executive director of the Wisconsin Farmers Union, said the study only took into consideration what he called two narrow measurements related to the healthfulness of milk. It didn't, he added, consider that the state's small farms often offer products that are organic or that come from grass-fed cows. "I think that products from the small farms often offer very significant benefits," Quinn added.

Quinn also said Ingham concluded that all milk from the state is of a very high quality.

"That's good news for everybody," he said.