From the NMC Newsletter "Udder Topics", April - May 2001

Delegates to the National Conference on Interstate Milk Shipments (NCIMS) did not accept either of the two proposals which would have lowered the U.S. somatic cell count (SCC) regulatory limit.

The National Mastitis Council's proposal would have lowered the SCC regulatory limit from 750,000 to 400,000 cells/ml in a stepwise fashion over four years, with the final effective date January 1, 2005. Regulatory action would have been based on a three-month rolling herd average (calculated using a geometric mean), rather than the current three of five consecutive samples exceeding the SCC limit. The NMC proposal was supported by the American Association of Bovine Practitioners and the American Veterinary Medical Association.

In addition to the NMC proposal, the New Hampshire Milk Sanitation Board submitted a proposal to lower the SCC limit from 750,000 to 500,000, effective July 1, 2002. (No type of SCC averaging was included in that proposal.)

Another proposal, submitted by the Wisconsin Department of Agriculture, Trade and Consumer Protection / Wisconsin Department of Health and Family Services, would have allowed state regulatory agencies to accept averaged somatic cell counts (four or more samples) collected during a calendar month for regulatory purposes. This was not supported by the delegates.

During the discussion of the NMC proposal, Dr. Michael Talley from the U.S. Food and Drug Administration (FDA) expressed concern that there may be public health risks associated with high SCC milk. (Studies referenced in the NMC proposal show increased incidence of drug residues and higher bacterial and coliform loads in high SCC milk.) However FDA is also concerned that the potential for drug residues could increase as high-SCC herds tried to reduce mastitis. Dr. Talley went on to say the FDA supported the concept of lowering the SCC limit to 400,000, provided the reduction would not result in an increase in antibiotic use and possibly more milk residues.

When Ontario, Canada first began lowering its SCC regulatory limit several years ago, producers with high SCCs and penalties for SCCs were also more likely to be penalized for antibiotic-positive milk tests. As the program progressed, the adoption of improved general management, plus the discovery by producers of the poor cure rates for chronically infected cows, soon limited this practice. Others point out that when the U.S. lowered its limit from 1,000,000 to 750,000 a decade ago, there was no detectable increase in antibiotic usage.

NCIMS meets every two years to consider proposed changes to the Pasteurized Milk Ordinance (PMO) and allied documents. These regulations establish the condition under which Grade A milk is inspected, produced, hauled, processed, stored and packaged. This year's conference was held May 5-10 in Wichita, Kansas. Conference participants include representatives from industry, government and educational institutions. Voting delegates are limited to state rating and enforcement agency representatives. All conference actions are subject to review and concurrence by the FDA. Additional information regarding NCIMS can be found at www.ncims.org.