Time to Change, Part 2

Posted: December 14, 2010

High milk quality is a product of management and not treatment.

(Editor's Note: This article appeared in the Fall 2010 edition of Commercial Agriculture and is reprinted here with permission of the authors.)

In the last Commercial Ag newsletter Drs. Steevens and Poock discussed the current recommendation for lowering the bulk tank somatic cell count (SCC) level from 750,000 to 400,000. In that article, we shared the rational in relation to the European Union’s (EU) demands for importation of milk from the United States. Any milk coop that will eventually have any of its milk going to the EU will need to abide by this standard. The segregation of that milk would become a logistic nightmare. Therefore, producers should expect the 400,000 mark to become the standard for the industry. Not only will this standard be helpful to increase exports, hopefully with an increase in price to the producer, but attaining high quality milk will benefit the cow.

It is well established that as milk quality improves (a decrease in herd SCC), there is a corresponding increase in production. In general, as a cow’s SCC doubles, there is a corresponding loss of production at 0.6 to 1.3 pounds per day for first calf heifers and mature cows, respectively. Likewise, analyzing data from farms that we track, there is a decrease in clinical mastitis as SCC is lowered in the herd. This reduces drug costs and increases the health of the cow. Both of these improvements will help the bottom line of the farm.

Similarly, there has been data showing the effects of mastitis on reproduction. A cow, that experiences clinical mastitis, has more days open than one that does not. Once again, analysis of several herds shows this trend. There were 8 herds analyzed, with ~ 7000 cows that had not experienced a case of mastitis and ~2200 cows that had. The cows that did not have a clinical case of mastitis averaged 124 days open compared to 142 for those cows that were treated for mastitis. A graph from one of the herds is below.

Days open for Cows with or without Mastitis

Interestingly, not only do cows that have to be treated for mastitis have more days open, but they tend to abort more pregnancies. Dr. Jose Santos looked at these abortion rates and found that those that were treated for mastitis had about twice the rate of abortions than those that did not have to be treated.  The highest abortion percentages were for cows that had a case of mastitis prior to first breeding. 

In regard to specific bacteria, Dr. Dale Moore showed that gram negative organisms could cause altered heat lengths via decreased luteal phases. These gram negative organisms are found in the environment, so cows’ cleanliness and teat prep, are vitally important to reduce their incidence.

This brings us to our final point in regard to milk quality. The FDA is developing more sensitive tests that will detect drugs at lower levels. When we say drugs, we do not mean antibiotics only.  Likewise, anytime a farm has a violation on meat residues, the FDA will begin to scrutinize the milk more closely as well. There is now a $63,000,000 case against a farm for using an unapproved drug and contaminating a co-op’s milk that went to China. So, work with your veterinarian to establish treatment protocols. First and foremost, use medications that are labeled for treating mastitis and adhere to withdrawal times. Second, if an extra label drug (ELDU) needs to be used, you MUST have your veterinarian’s permission, protocol, and extended withdrawal times. Lastly, if your veterinarian says a drug is NOT for use in lactating cattle, do NOT use it!

To wrap up this topic, first the SCC changes are coming. In the long run, it will be good for the industry. We will be producing a high quality product. Many producers already below the proposed standard of quality. Second, high milk quality is a product of management and not treatment. Work with your farm advisors to implement strategies to improve SCC. Improved milk quality will yield more milk and better reproduction, both will enhance the producer’s bottom line.

- Dr. Barry Steevens, Dairy Specialist, and Dr. Scott Poock, Veterinarian, University of Missouri Extension