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Northern Valley Dairy Production Medicine Center


900 N. Wabasha, Plainview, Minnesota 55964 (507) 534-4356
Office Hours:

Monday-Friday
7:30 AM-5:00 PM

Saturday
8:00 AM-12:00 PM

​Sunday-Closed

24-hour Emergency Service
Milk Quality
Mastitis is the second largest cost to dairy producers nationally. This loss comes from reduced quality premiums, discarded milk, treatment costs, reduced milk production, and culling of infected cows. Consumers are also increasingly demanding a higher quality product. Producers who can produce high quality milk at a low cost will have a great advantage in tomorrow’s marketplace.

We can help you produce quality milk. Somatic cell counts can consistently be below 150,000 on well-managed dairies. New cases of clinical mastitis can be limited to one or two percent of the herd per month. Well-managed dairies know that it is important to prevent mastitis, detect and treat clinical mastitis early and appropriately, and monitor results on a regular basis. We can evaluate your farm and analyze your records, identify key areas where improvements will make a significant impact, design a plan to address these areas, and work with you to implement changes and monitor future performance. Some of the tools that we utilize are described below.
Bulk Tank Cultures

Bulk tank milk cultures generally tell us two things about a dairy: if there are cows in the herd infected with contagious mastitis pathogens and the effectiveness of its milking hygiene practices.

Contagious pathogens, such as Strep ag and Staph aureus, almost always get into the bulk tank by infected cows shedding these bacteria in their milk. These pathogens are spread cow-to-cow during milking, so if found in the bulk tank, steps should then be taken to identify the infected cows and treat, segregate, or cull to prevent the spread to uninfected cows.
​Environmental bacteria in bulk tank milk, on the other hand, primarily come from contamination of the milk after it leaves the udder. These bacteria include coliforms, environmental Streps, and coagulase-negative Staph, and are normally found in the environment and on teat skin. High levels in the bulk tank milk correspond with a high risk of new mastitis infections caused by these environmental organisms. Control measures have two objectives: keeping cows as clean as possible between milkings and making sure the teats are disinfected and dry prior to milking unit attachment.
​We perform bulk tank cultures in our laboratory using methods designed by the University of Minnesota and the University of Wisconsin. (See our Laboratory Page.) We recommend bulk tank cultures to be performed at least on a monthly basis, regardless of herd size.
​Individual Cow Milk Cultures

The purpose of an individual cow milk culture is to find out what organism is causing a mastitis infection. Reasons why culturing is important include:
We recommend culture-based treatment of grade I and II clinical mastitis (the cow is not systemically ill). This means collecting a milk sample for culture at the time abnormal milk is detected, and waiting to treat the cow until culture results are known. Studies show that delaying treatment for up to seven days will not decrease the cure rate of a mastitis infection. Our laboratory can usually provide preliminary results the following day, before the time that cows are normally treated on your farm. (See our Laboratory Page.) Culture-based treatment allows for selection of an appropriate intramammary antibiotic, frequency of administration, and duration of therapy aimed to cure an infection with the particular organism identified. Advantages of culture-based treatment include:
  • ​You cannot tell what organism has caused a mastitis infection by examining the milk or the cow.
  • The milk returning to a normal appearance following treatment does NOT mean that the infection has been cured.
  • The milk remaining abnormal in appearance after the completion of a treatment regimen does NOT mean that the infection was not cured.
  • Some organisms cause chronic mastitis infections that will not respond to any treatment.
  • Some organisms cause short-lived mastitis infections that will cure without treatment.
  • One mastitis organism (yeast) does not respond to treatment, and in fact may take longer to self-cure if antibiotics are used.
  • ​Better cure rates for treatable mastitis pathogens, due to appropriate treatment, and therefore fewer of these infections becoming chronic (the cow’s somatic cell count staying high, even if the infection goes subclinical and the milk appears normal) due to treatment failure
  • Saving money by not treating cows that do not require it, because the organism causing their infection is known to self-cure with time, or the culture result is “no growth,” meaning the cow’s immune system has already killed the organism that caused the infection
  • Saving money by not treating cows that will not respond, because the organism causing their mastitis produces a chronic, incurable infection
  • Identifying cows infected with contagious pathogens, so that they can be treated, segregated, or culled, to prevent the spread to other cows
Culturing cows with chronically high somatic cell counts, even in the absence of clinical mastitis, is often also useful. You may identify cows harboring potentially contagious, chronic infections that will not respond to therapy. Staph aureus and Prototheca are examples. These cows should be segregated, milked last, or culled. You may also find animals infected with organisms that typically respond well to therapy, such as coagulase-negative Staph, for example. They can be treated and hopefully returned to the milking string as clean cows, reducing your bulk tank somatic cell count.
Sometimes it is a good idea to individually culture milk from every cow in the herd. This is often recommended when you know there are cows infected by a contagious mastitis pathogen, for example, when Strep ag has been found on a bulk tank culture. This organism only lives in the udders of cows. If every infected cow is identified and either successfully cured with treatment or culled, it can be eradicated from the farm. In these situations it is essential to culture and identify every infected cow, because if even one is missed, she may rapidly infect the others. Therefore it will also be important to screen all cows that are dry at the time, as soon as they freshen, and milk them last until culture results are known.
We perform individual cow milk cultures in our laboratory, using procedures standardized by the University of Minnesota and the National Mastitis Council. Quarterly, we participate in Cornell University’s laboratory proficiency test to ensure that we are up-to-date and accurate. (See our Laboratory Page.) Alternatively, we can train you to use the Minnesota Easy Culture System II for on-farm culturing. We can monitor your results and can periodically test your farm laboratory by sending you samples from our lab and checking your results against ours.
Milking System and Milking Time Analysis, and much more

Most intramammary infections occur at milking time. Some level of infection is unavoidable on any dairy, but using proper milking procedures with well-designed and well-maintained equipment can prevent most mastitis.

The goal of a milking system analysis is to make sure that all components of your milking equipment are functioning correctly. We have the testing equipment to perform milking system analyses using methods standardized by the National Mastitis Council.
But the human factor is equally important, so we also perform milking time analyses, during which we observe milking routines and techniques, and measure important milking preparation indices. This is also a good time to do teat end and udder hygiene scoring. After making observations and analyzing the collected data, we can make specific recommendations on changes that should be made, and can even help train your staff on procedural changes.

Often on larger farms, the person milking the cows is not aware of the level of milk quality on the dairy. If this is the case, you may be asking these employees to make changes for which they cannot imagine the possible benefit. We can help you design a few simple monitors for your milking crew to watch so that they know the results of their efforts.
We can also evaluate the cleanliness of your cows and their living environment. This is important, because even an excellent milking technician and the world’s best teat dip cannot remove 100% of the bacteria from a cow’s teats prior to milking. Therefore, the goal is for cows to be as clean as possible prior to entering the parlor. Walking through cow areas and making careful observations can quickly identify problems such as splash zones, improper stall design, or poor bedding and manure management. We also utilize laboratory tools such as towel cultures, bedding cultures, and water cultures. (See our Laboratory Page.)
Mastitis Control and Record Analysis

Your records, whether computerized, DHI reports, or handwritten can offer valuable insights as to the root causes of mastitis on your farm. Do heifers tend to calve infected? Are infections occurring during the dry period? What is the incidence of clinical mastitis on your farm? We have extensive experience evaluating dairy records and can help you identify and solve problems through record analysis.
We pride ourselves in our ability to solve problems and make practical, feasible recommendations. Furthermore, we believe it is important to monitor the implementation of changes to make sure that they result in measurable improvement and do not decrease the efficiency of the dairy’s day-to-day operations.
Future Challenges

Producing quality milk and keeping mastitis incidence low has never been more important than today. More and more, United States dairy farmers export milk around the world. Many countries have tougher milk quality standards that we do, so to keep exporting milk, our industry will have to continue to work hard to meet their requirements. In addition, U.S. consumers are consistently demanding quality products, and will define quality based on their wants rather than what we may easily be able to provide. Give us a call to find out how we can help you. We will customize our approach to fit your farm and your needs.