Milk quality begins with a well-trained milking staff. Here’s a primer for your employees on the basics of somatic cell counts.
By Tom Van Dyke, DVM, Manager of Veterinary Services, Merial
Lowering somatic cell counts (SCC) is an ongoing challenge for the dairy industry. It is important for producers to not only educate themselves on the negative impacts that SCC counts can have on milk quality but also communicate that information to their employees.
SCCs are considered to be a key indicator of milk quality and are a measure of somatic cells in milk. The raw somatic cell score is given in number of cells per mL of milk such as 200,000, 400,000 or 750,000. For ease of reporting and calculations, these raw counts are also converted to log or linear scores (1,2,3,).1
Somatic cells are primarily inflammatory cells that arrive at the mammary gland in response to irritation, which is most commonly the result of bacteria that have entered through the teat opening. Typically, these bacteria are classified as either contagious or environmental. Contagious bacteria are those that have adapted to thrive inside the mammary gland of the cow and are spread from cow to cow during the milking process. Environmental bacteria are opportunistic and infections occur when cattle are exposed in the farm environment.1
Cattle with milk SCCs of less than 200,000 are arbitrarily considered uninfected while those with counts of more than 200,000 are judged to be infected. The bulk milk tank SCC on any farm measures the success of management practices, which help minimize exposure and growth of bacteria in the udder.2
Milk quality has financial implications. Milk processors want a decreased SCC because it reflects increased cheese yield and maintains milk quality. Milk marketing cooperatives often pay premiums to producers of higher quality milk. Milk quality-related economic losses at the farm level occur as a result of lost premiums, cow treatment costs, milk discard and cow culling.
The greatest loss, however, often comes from decreased production in infected cows. On average, for every one point increase in SCC linear score, a pound of daily milk production per cow is lost, and these losses can add up quickly.3
Currently, the SCC limit for milk sold in the U.S. is 750,000 cells per mL.1 Milk marketed in Europe must have a SCC below 400,000. The National Milk Producers Federation has proposed a reduction in SCC in the U.S. to 400,000 by 2014. Improving milk quality will be imperative for many farms just to stay in business.4
For U.S. producers to meet increased standards, more emphasis will need to be placed on sound milking management practices and increased culling. For this type of effort to be successful, however, it must involve the entire team — producer, manager and employees.5
Milk quality begins with a well-trained milking staff. Educating dairy employees about uniform practices such as pre- and post-milking procedures, cow comfort, mastitis detection and milker hygiene, can make a significant difference in milk quality.5 Demands on management time and talents are likely at the limit already. Finding the time, though, to develop and implement a training program is a challenge. Language barriers may also complicate matters.
Fortunately, resources are available to help dairies conduct training for their employees. One such resource is the Best In Class Dairies Program (BestinClassDairies.com), which provides dairies access to valuable information and educational tools to help ensure healthy cows, the highest standard of milk and profitable operations. The educational modules are designed to expand employees’ knowledge base, implement what they have learned and allow them to witness firsthand the dramatic differences that even the smallest changes can make.
The online training program also enables managers to track the progress and test scores of their workers, thereby identifying the strengths and weaknesses of their employees. Managers can then make informed decisions about training needs based on individual testing results. This makes the operation, as well as the workers, more productive.
©2011 Merial Limited, Duluth, GA. All rights reserved. RUMILGN1147 (04/11)
1 Pennington JA. Reducing Somatic Cell Count in Dairy Cattle. University of Arkansas Cooperative Extension Service FSA4002-PD-3-06R.
2 Dohoo IR, Leslie KE. Evaluation of changes in somatic cell counts as indicators of new intramammary infections. Preventive Veterinary Medicine. 1991;10 (3): 225-237.
3 Ruegg, Pamela. Premiums, Production and Pails of Discarded Milk.
How Much Money Does Mastitis Cost You? University of Wisconsin, Madison pub 3-56 2005. Available at:
4 Reneau J, More EU. SCC Requirements Details. University of Minnesota Extension. Available at: http://www1.extension.umn.edu/Dairy/milk-quality-and-mastitis/eu-scc-requirements/. Accessed March 14, 2011.
5 Bray DR. Managing Milk Quality and Profit in the Parlor. University of Florida Dairy Update. 2010;10 (4).