A study of Upper Midwest farms shipping milk into the Federal Order in 2014 systems shows Michigan’s Upper Peninsula farms have the lowest somatic cell counts. The “Uppers’” Grade A farms averaged 210,000 cells/mL, some 12,000 less than the average for the entire Upper Midwest Federal Order.
Wisconsin farms had the second lowest level of somatic cells, at 216,000 cells/mL. North Dakota Federal Order farms averaged the highest somatic cells, at 249,000 cell/mL, followed by South Dakota, at 242,000.
Iowa, Minnesota and Illinois were all clustered together, at 229,000, 231,000 and 233,000 cells/mL respectively.
“Somatic cell counts under the Upper Midwest Marketing Order have shown a sustained and substantial downward trend over the period from 2002 to 2014,” says Corey Freije, author of the report. In 2002, the Upper Midwest cell count average was 326,000 with a standard deviation of 153,000. For the past three years, the Upper Midwest cell count average has ranged from 220,000 to 224,000 with a standard deviation of just 104,000.
The study also showed that large farms also tend to have the lowest somatic cell counts. Herds shipping more than 5 million lb. of milk per month (roughly 2,500 cows or more), had cell counts average 205,000 cells/mL. Herds shipping up to 49,999 lb. per month had cell counts that average 321,000, the only herd size category to exceed 300,000 cells/mL.
In these very small herds, one high count cow can skew the tank average. Conversely, large herds tend to benefit from the dilution effect. In addition, large herds tend to have more standardized milking protocols that are applied to every cow at every milking.
You can read the full report here.