Premiums, Production and Pails of Discarded Milk How Much Money Does Mastitis Cost You?

© 2005, Pamela L. Ruegg Premiums, Production and Pails of Discarded Milk How Much Money Does Mastitis Cost You? Pamela Ruegg, DVM, MPVM University of Wisconsin, Madison Introduction Profit centered dairy farms strive to maximize milk price and control costs. One way to control costs is by minimizing the rate of disease. The most costly disease of dairy cattle is generally considered to be mastitis. Mastitis can cause both clinical and subclinical disease. On many farms, subclinical mastitis is the most economically important type of mastitis because of the long-term effect of chronic infections on total milk yields. Persistent long-term infections with contagious pathogens (such as Strep agalactia and Staph aureus) damage milk secretory cells and result in reduced milk production. A recent study estimated that the cost of subclinical mastitis to the US dairy industry exceeds $1 billion annually. The effect of subclinical mastitis is shown in the somatic cell count (SCC) at the individual cow level and ultimately in the bulk tank. The SCC of cows infected with subclinical mastitis rises as the cows immune system sends white blood cells to the udder to fight off mastitis pathogens. The association between herd bulk tank SCC and production losses was recently compared between herds with low SCC (<200,000/ml), herds with medium SCC (200,000-399,999) and herds with high SCC (>400,000/ml), (Figure 1). The overall production loss for the average US dairy farm was estimated at $110/cow annually.