Troubleshooting a High SCC

Dr. Clell V. Bagley, D.V.M.
USU Extension Veterinarian

    A high herd Somatic Cell Count (SCC) is an indication of chronic, subclinical mastitis in the herd. It is also an indication of significant economic losses. What is considered to be a “high” SCC? Anytime the bulk tank SCC is consistently above 200,000 it indicates there may be some problem. But, especially if the SCC is consistently over 400,000, or if less than 70% of the cows are in the 0-4 linear score (LS) category (on DHI records). These levels indicate the herd is suffering moderate to serious economic losses due to reduced production and lack of premiums. These dairy herds will have difficulty competing in the market, especially in times of reduced milk prices. If your herd has a high SCC consider one of the following, or a combination of them, as the likely problem(s). Get some help from the milk processor fieldman, your veterinarian or others to identify and resolve the situation.

• Malfunction of Milking Equipment - This is becoming less of a problem as more producers are having their serviceman provide regular preventive maintenance service. But equipment failure certainly can be a problem or contribute substantially to the SCC problem. For the average size dairy, if you have not had your milking equipment evaluated and serviced in the past six months, this would be a good place to begin troubleshooting.
  
  
• Dirty Cows - If over 5% of the cows are heavily contaminated with manure on the rear legs and udder (especially on the teats), there is a problem with the corral, freestalls, bedding, or their management. It is very common for environmental Strep and Staph organisms to be present in the udders of many of these cows. These organisms cause chronic, subclinical mastitis and a significant rise in the SCC. Determine the cause of the dirty cow problem and fix it so most of the cows are clean as they come to the parlor. Freestalls need to be properly sized so the cows don't manure and urinate in the back of them. They also need to be re-bedded often and raked and leveled daily. It will also help to flame the hair from the udders of cows, but be careful not to burn the skin if they have manure balls stuck to the hair. Keep cows clean, dry and comfortable.
  
  
• Dry Period and Maternity Management - Allowing the dry cows to be housed in areas of puddles and wet manure packs will increase the percent of udders infected at freshening. This increases the SCC and may result in mastitis which decreases production for the entire lactation. This is a critical time in the lactation cycle. Keep these cows very clean, dry and comfortable, especially at calving.
  
  
• Contagious Mastitis and Milking Procedures - The most common form of contagious mastitis in Utah is caused by Staph aureus. Almost all herds have some infected cows. With frozen teat ends or faulty milking procedures, a small problem can rapidly erupt into a major disaster. Review your milking preparation procedures and compare them to the ideal and make improvements where needed. (See the announcement of the new USU videotape on "The Milking School" in this issue of the Dairy Newsletter.)
  
  
• Vitamin E and Selenium Levels - These have both recently been shown to have a profound effect on udder health and resistance to infection. Blood tests can help evaluate and monitor the herd status. Over-dosing is not a cure-all, but it is critical that adequate amounts be present. Both vitamin E and selenium can be added to the feed at minimal expense to insure adequate intake.
  
  
• Post Milking Teat Dipping and Dry Cow Therapy - Both of these are valuable tools that should usually be incorporated into the management plan for most herds. If you are not using these tools, perhaps you should be.

Short Check List:


• Teat dip all cows.
• Treat all quarters of all cows with dry cow therapy, as they turn dry.
• Have milking equipment checked and serviced at least every six months.
• Review milking practices. Don't use sponges, cloths or high volume hoses.
• Keep cow udders clean between milkings.
• Avoid injury to udders, especially the teat ends.
• Reduce squawks and milk machine fall offs.
• Cull chronic problem cows.
• Culture and identify the predominant organisms causing the herd problem.
• Supply adequate vitamin E and selenium.

        Is your herd SCC high?
        Which of the items listed above (or combination of them) is the most likely contributor?
        What do you need to do to change the situation?
        Do you need help in confirming the cause of the problem, so you will put in the needed effort?
        When will you take the next step?