MILWAUKEE (AP) — With buying from small, local, family-run farms becoming more popular, the results of a new study from Wisconsin could be surprising: It found that milk from big dairies is cleaner than that from small ones.
Lead researcher Steve Ingham said he did the study because he wanted to see whether there was a link between milk quality and the size of a dairy farm. He said the results cast doubt on the perception that big dairies can't match smaller ones in terms of quality.
"Certainly, the small-is-better blanket statement doesn't appear to be true," said Ingham, who started the study when he was a food science professor at the University of Wisconsin-Madison and is now a food safety division administrator at the Wisconsin Department of Agriculture, Trade and Consumer Protection.
But a group that represents small farms said the study was irrelevant because of the way it defined milk quality. It looked at the amount of certain cells and bacteria in milk, which are factors agriculture inspectors use to evaluate cows' health and farms' cleanliness.
Tom Quinn, the executive director of the Wisconsin Farmers Union, said the study ignored other aspects of quality, such as taste and nutrient levels. It also didn't address what he said are the real reasons smaller farms are better.
"I don't recall that we've ever claimed small farms are better because they produce more sanitary milk," he said. "Instead we've made that argument from environmental, economic and social issues."
The study published in the August issue of the Journal of Dairy Science used 2008 data collected by the Wisconsin government to look at levels of cells linked to mammary disease in dairy cows and bacteria tied to improper refrigeration or unclean equipment.
It found milk produced at large and extra-large farms had lower levels of both bacteria than that produced by small ones, although all the farms met standards for grade A milk certification.
Because he used data exclusively from Wisconsin, the nation's second-leading milk producer behind California, Ingham said he wasn't sure whether the results would apply elsewhere, especially in warmer states where bacterial growth might be harder to prevent.
He said the perception that smaller was better seemed to spring from the belief that small farmers have a greater incentive to collect milk hygienically and avoid taxing their cows with over-milking.
However, he noted, larger operators also have an incentive to keep their herds healthy, including by removing cows that have udder infections so they don't infect others. Bigger farms also keep bacterial counts down by investing in better sanitation and refrigeration equipment, he said.