by Amanda Smith, Associate Editor
Somatic cell count is indicative of the quality of the nation's milk supply. There is an inverse relationship between the bulk tank somatic cell count (BTSCC) and cheese yield along with the quality/shelf life of pasteurized fluid milk, noted a recent report from the Animal and Plant Health Inspection Service.
That group, in conjunction with the USDA's Agricultural Marketing Service and the National Mastitis Council's Milk Quality Monitoring Committee, monitor BTSCC data from the Upper Midwest, Central, Mideast and Southwest federal milk marketing orders.
The milk-weighted geometric BTSCC mean in 2014 was 193,000 cells/mL, which was essentially unchanged from 2013 (Figure 1). The milk-weighted value takes into account the amount of milk shipped by a producer, resulting in an overall BTSCC mean. The producer shipment BTSCC, a nonmilk-weighted mean of all shipments, was 229,000 cells/mL.
More than 99 percent of the milk and shipments monitored were below the Pasteurized Milk Ordinance limit of 750,000 cells/mL. Of the 26,424 producers in the four orders, 95.6 percent shipped milk below 750,000 BTSCC during all monitored months.
A similar percentage of the milk produced was below 400,000 cells/mL (Figure 2). Nearly 65 percent of producers shipped milk below this cut point for the entire year. Half of the shipments in all monitored orders had a BTSCC between 200,000 and 399,000 cells/mL.
Since 2009, the percentage of milk shipped with a BTSCC less than 200,000 cells/mL has risen from 40.1 to 53.9 percent. Based on EU Health Certification standards, which require a three-month geometric mean BTSCC below 400,000 cells/mL, only 5 to 8 percent of U.S. shipment would have been noncompliant during 2014.
