Dairy--Animal Management
NEW SCC STANDARDS
General
As of July 1, 1993, the maximum allowable somatic cell count (SCC) for milk becomes 750,000 cells/ml. The old standard of 1,000,000 is gone. While 90+ percent of our dairy producers consistently produce milk with SCC below the action level, a small percentage of our producers may face regulatory action.
Summertime and high SCC often go together. Each producer must evaluate his/her management to control mastitis. There are a number of things to consider when attempting to prevent mastitis:
- Much of the summertime mastitis is of an environmental origin; therefore, controlling the cows environment is necessary to prevent mastitis and high SCC.
- a. prevent cows access to wet area, i.e. in and around streams, ponds, contaminated loafing areas, water tanks and dirty free stall housing
- b. provide shade and drinking water to maximize comfort thus reducing stress. Cows under environmental stress have less ability to fight bacterial invasion.
- Control contagious mastitis, St. agalactiae and Staph. aureus, by following good milking procedures and by having a proper, working milking system. Pre-dipping and post-dipping of teats with an approved product is a good program to follow to reduce bacteria numbers on teats. The use of single-use towels to dry udders is also an important practice in preventing mastitis (environmental and contagious).
- Use antibiotic treatment judiciously. More and more research is suggesting that antibiotics have limited effect, i.e. cure rate, on mastitis infections, particularly environmental types as well as Staph. aureus infections.
- Culling or removing cows with high SCC from the milking string is the fastest and most effective way of reducing SCC in the bulk tank. Cows with Staph. aureus infections should be prime candidates for culling, particularly those with chronic mastitis (reoccurring outbreaks).
- Culturing of milk samples to determine the infective organism is essential for an eradication program. The Clemson University Diagnostic Lab at Pontiac, cultures milk samples for $1 per sample.
- Nutrition is important in mastitis control. Several minerals and vitamins play a role in good udder health and the immune system to prevent new infections.
Controlling mastitis and thus preventing high SCC is a constant battle. Following good management practices is essential in keeping mastitis under control.
Nutrition Important in Mastitis Control
Certain dietary nutrients play a role the cow's ability to resist udder infection. Selenium is an essential nutrient in body tissues, including the mammary gland. Vitamin E is another essential nutrient and serves to maintain health cell membranes in the mammary gland. Both are needed for proper udder immune function. There appear to be several ways in which selenium and vitamin E work together to fight disease:
- Selenium and vitamin E are needed by white blood cells to fight mammary gland infections.
- Selenium and vitamin E may influence immune system function by affecting the amount of antibodies present in the udder. Antibodies help neutralize bacterial toxins and promote engulfment of bacteria by white blood cells.
- Selenium and vitamin E indirectly influence smooth muscle function. The teat canal is surrounded by smooth muscles, and deficiencies in these nutrients may decrease muscle tone and lead to increased entry of bacteria into the udder.
Vitamin A and beta-carotene are also needed for the mammary immune system to function properly. These substances maintain milk secretory cell health and promote antibody transport and white blood cell movement into milk.
Taken from Udder Topics, Vol. 16, No. 2, NMC, April 1993.