Somatic cell counts ticked slightly upward last year in four Federal Milk Marketing Orders monitored by USDA's Animal and Plant Health Inspection Service.
The milk-weighted geometric BTSCC mean in 2007 was 260,000 cells/ml (compared to 249,000 in 2006 and 258,000 in 2005). The milk-weighted BTSCC takes into account the amount of milk shipped by a producer, resulting in an overall BTSCC mean of monitored milk. Milk was sampled from the Central, Mideast, Southwest and Upper Midwest Federal Oderrs. These FMOs monitored milk from 36,528 producers located in 32 states and accounted for nearly half of the country's milk supply.
More than 99% of the milk shipped in these FMOs during 2007 met the current Pasteurized Milk Ordinance SCC limit of 750,000. In addition, 83.2% of the monitored milk had BTSCCs less than 400,000, which is the current European Union SCC regulatory limit.
The weighted means suggest larger producers are shipping milk with lower somatic cell counts. Of the 36,528 producers monitored in the four FMOs during 2007, 88.6% shipped milk with BTSCCs below 750,000 during all the months monitored while 43.8% of the producers shipped milk with BTSCCs below 400,000.
Monthly monitoring continues to show that BTSCCs peak during July through September. In 2007, monthly milk-weighted BTSCCs were highest during August (299,000) and lowest in December (232,000).
Twelve of the 14 States shipping 60% or more of their milk through the four FMOs monitored in the study had higher BTSCCs in 2007 compared to 2006. The largest increase was observed in the Southwest FMO (primarily Texas and New Mexico).