2018 DHI Somatic Cell Counts Lowest Ever
An analysis of somatic cell counts (SCCs) from Dairy Herd Improvement herds shows 2018 had the lowest average SCC ever at 191,000 cells/mL.
When SCC levels were first summarized in 1995, the national average stood at 304,000 cells/mL. So the 191,000 cell level in 2018 represents a 37% decline over those 24 years. The annual trend in cell count decline is 6,700 cells/mL, reports Duane Norman, a consulting scientist with the Council on Dairy Cattle Breeding.
Small herds tend to have the highest cell counts, with herds with fewer than 200 cows still averaging above 200,000 cells/mL. Herds with 500 or more cows have cell counts that average below 185,000 cells/ml.
Over the years, there has been some discussion of lowering the national SCC limit to 400,000 cells/mL. (Milk used in dairy products sold for export must already meet this limit due to European Union milk quality standards.)
“If the limit is set at 400,000 mL, 17.3% of monthly tests would fall above the limit for herds with fewer than 50 cows, 10.9% for herds with 50 to 99 cows, 7% for herds with 100 to 149 cows, but only 0.6% for herds with over 3,000 cows,” says Norman.
Herds in the southeast also struggle with higher SCC levels. For example, Arkansas averaged 411,000 cells/mL and Alabama averaged 388,000 cells/mL in 2018.
“Although climatic conditions (temperature and humidity) surely contributed to regional SCC levels, differences between adjacent states were substantial, suggesting herd size and mastitis-control practices are impacting state differences as well,” says Norman. Florida has an SCC average of 262,000 cells/mL and Mississippi had an SCC average of 295,000 cells/mL in 2018, as examples.
Vermont had the lowest SCC average in the nation, at 156,000 cells/mL; Michigan was second with 158,000 cells/mL, and Utah third, at 160,000.
California, the nation’s largest milk producer, had an average SCC of 204,000 cells/mL. Wisconsin, the second largest milk producer and largest cheese maker, had an average SCC of 172,000 cells/mL.
You can read the complete report here.