July 18 2013 08:29 AM

Across the four monitored milk-marketing orders, a 5.9 percent drop in somatic cell count was achieved.

U.S. dairy producers continued to make strides toward lowering bulk tank somatic cell count (BTSCC) levels this past year. Across four federal milk marketing orders, producers saw a 5.9 percent drop in BTSCC, from 206,000 cells per milliliter (mL) to 194,000 cells/mL according to information provided in a July 2013 release from the USDA Animal and Plant Health Inspection Service (APHIS).

The data comes from the four federal milk marketing orders (FMO) that report BTSCC. These include the Central, Mideast, Southwest and Upper Midwest. These four orders monitored milk from 28,274 producers located in 31 states. The data also accounted for 94.8 billion pounds, or 47.4 percent, of the 200.3 billion pounds of milk produced in the U.S. in 2012. In total, 309,343 milk shipments were monitored.

This milk weighted BTSCC takes into account the amount of milk shipped by a producer, resulting in an overall BTSCC mean of monitored milk. The producer shipment BTSCC (the geometric, nonmilk-weighted mean of all shipments) dropped from 259,000 cells/mL in 2011 to 230,000 cells/mL in 2012.

Since 1997, the milk-weighted BTSCC in the U.S. has dropped 101,000 cells/mL or 34.2 percent. Similarly, producer shipment BTSCC has lowered 26.5 percent.

More than 99 percent of milk and shipments monitored met the current Pasteurized Milk Ordinance (PMO) limit of 750,000 cells/mL. Of the 28,274 producers, 96.5 percent also fell below this mark. Additionally, 95.6 percent of milk shipped was less than 400,000 cells/mL. For the year, 64.5 percent of producers, too, shipped milk below this limit.

Only 5.2 billion pounds, or 5.5 percent remained under the 100,000 cells/mL mark for the entire 2012 monitoring period. Only 0.9 percent of the 28,274 producers stayed under this target for the entire year.

Half of the shipments in 2012, across all orders, had BTSCCs between 200,000 and 399,000 cells/mL. The four orders had a similar percentage of shipments distributed among the four BTSCC levels, although a slightly higher percentage of shipments in the Mideast region were below 400,000 cells/mL (see figure).

BTSCCs for all monitored orders combined have fallen every year since 2007. With the exception of the Southwest order in 2010 and 2012, milk-weighted BTSCCs have also dropped in each order since 2007.

The Upper Midwest and Central orders had the highest BTSCCs during 2012 at 199,000 and 198,000 cells/mL, respectively. The Mideast order had the lowest at 180,000 cells/mL, while the Southwest has shown the most variation from 2009 to 2012.

Fifteen states marketed 60 percent or more of the milk produced in their states through the monitored orders and accounted for 95.3 percent of the monitored milk in the four orders. Thirteen of these 15 states had lower BTSCCs in 2012 compared to 2011.
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The author, Amanda Smith, was an associate editor and is an animal science graduate of Cornell University. Smith covers feeding, milk quality and heads up the World Dairy Expo Supplement. She grew up on a Medina, N.Y., dairy, and interned at a 1,700-cow western New York dairy, a large New York calf and heifer farm, and studied in New Zealand for one semester.