Report Summarizes Bulk Tank Somatic Cell Count Data in 2011

Milk quality in the U.S. is monitored by USDA in conjunction with NMC

The U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service's Centers for Epidemiology and Animal Health (CEAH), in conjunction with the USDA Agricultural Marketing Service (AMS) and the National Mastitis Council (NMC) Milk Quality Monitoring Committee, monitor milk quality in the U.S. using bulk tank somatic cell count (BTSCC) data provided by four of the nation's 10 Federal Milk Marketing Orders (FMOs). The remaining six FMOs do not collect BTSCC information.

In 2011, four FMOs were monitored: Central, Mideast, Southwest and Upper Midwest. These FMOs monitored milk from 29,937 producers located in 29 states and accounted for 46.5% of the 196.2 billion pounds of milk produced in the United States in 2011.

2011 Bulk Tank SCC Data

The milk-weighted geometric BTSCC mean was 206,000 cells/ml in 2011. The milk-weighted BTSCC takes into account the amount of milk shipped by a producer, resulting in an overall BTSCC mean of monitored milk.

In comparison, the milk-weighted geometric BTSCC was 224,000 in 2010; 227,000 in 2009; 247,000 in 2008; 260,000 in 2007; 249,000 in 2006; and 258,000 in 2005.

The producer shipment BTSCC was 259,000 in 2011. The producer shipment BTSCC is a geometric, nonmilk-weighted mean of all shipments (i.e. all shipments have equal weight)

In comparison, the producer shipment BTSCC was 272,000 in 2010; 277,000 in 2009; 294,000 in 2008; 298,000 in 2007; and 293,000 in both 2006 and 2005.

Milk-weighted and Producer Bulk Tank Somatic Cell Count, 2006-2011
Figure from USDA APHIS infosheet (September 2012)

Evaluating BTSCC Levels
More than 99% of the milk and 98% of the shipments monitored in these FMOs during 2011 met the current Pasteurized Milk Ordinance SCC federal regulatory limit of 750,000 cells/ml. Of the 29,937 producers, 92.3% shipped milk with BTSCC below 750,000 during all months monitored.

In 2011, during all monitored months, BTSCCs in 92.7% of milk was less than 400,000 cells/ml. Only 53.6% of producers shipped milk below 400,000 for the entire year.

Almost 50% of shipments in the FMOs monitored had BTSCCs between 200,000 and 300,000.

Seasonal Trends
Monthly monitoring continues to show that BTSCC peak during the summer months (July - September). In 2011, monthly milk-weighted BTSCCs were highest in August (243,000) and lowest in November (188,000). With the exception of December, BTSCCs were lower in all months during 2011 compared with 2010

For more information, including State comparisons, see the USDA APHIS factsheet:

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