Jeffrey K. Reneau, Extension Animal Scientist, Dairy management

October 7, 2005

If you were to ask most Minnesota dairy managers whether they followed most of the known NMC mastitis prevention practices like pre and post milking teat dipping, dry cow therapy, routine milking equipment maintenance, sanitary milking procedures and careful bedding management, just to mention a few, they would almost without exception answer yes. Yet there is obviously a large difference in the quality of milk coming from Minnesota dairies. Our recent survey indicates that although half the Minnesota dairies produce milk with a somatic cell count under 400,000 “most” of the time, less than 25% of these dairies are producing milk under 400,000 “all” of the time.

If most farms have implemented these proven mastitis and milk quality best management practices, why is there such enormous variation in milk quality? Ah you say, it’s not just the fact that they do these practices, it’s how well they do them and how consistently they do them! You are exactly right!

But, it goes back to the familiar question of “which came first, the chicken or the egg?” Is it more important to do the job right or to do the job consistently? This circular question has been debated over and over. I’ve recently heard a dairy nutritionist say that a better result may come from feeding a mediocre diet consistently rather than to have a higher quality diet fed inconsistently. This could be true, but of course it is always best if you can have your cake and eat it too. That means not only doing the job right but also doing it right consistently.

How did you do this past summer in keeping your BTSCC (bulk tank somatic cell count) low? It is obvious that some of you struggled to keep your BTSCC under control. July and August 2005 were the first months in 24 consecutive months that the Minnesota’s DHI average BTSCC was higher than during the previous year. So, what can we do to get ourselves back on track?

First, check your BTSCC average and day-to-day BTSCC variation against the arrow charts shown in Figure 1. If your variation is greater than expected for your current BTSCC average, look for problems of inconsistency and correct them. For example, are all milkers following the proper milking procedure of getting teats clean before applying the milking machine? This is thought to be the most important step in reducing BTSCC. If your consistency is as expected or even better than expected for your present BTSCC level, then you will need to look for ways to do things better. For example, increase the intensity of your bedding management, such as re-bedding daily instead of every other day. For more detailed information see, the Milk Quality page.

If I had to pick which to concentrate on first, I would work on improving consistency, then work on improving the processes associated with achieving milk quality. Usually, if you are not getting the results you feel you should be getting, it could be that you are doing the right things but you are inconsistent in applying them. If that is the case, working on consistency should improve your day-to-day BTSCC variation as well as reduce the BTSCC level. Once you achieve excellent consistency but still want to make further improvements in BTSCC, you need to look for ways to do things better. The combination of excellent work and that work done consistently is guaranteed to produce excellent results.

Figure 1. BULK TANK SCC  

ARROW A (Herds less then 100 cows)

ARROW B (Herds 100 cows or more)

The BTSCC data shows that in order to consistently have low BTSCCs, you need both excellent processes and consistency. Recent BTSCC analysis of every bulk tank pickup of 1,501 Midwest dairies shows that low BTSCC averages and low day-to-day BTSCC variation go hand-in-hand. Notice that herds with low bulk tank somatic cell counts also have the lowest day-to-day BTSCC variation.

Figures 2 and 3 are two graphs with each line showing the month to month BTSCC averages and day-to-day BTSCC variation values on 1,501 Midwest dairies for 2003 and 2004. BTSCC tests were completed on every milk pickup for this 2-year period. The BTSCC standard is listed on the right side of the graph. For example, the lowest line on each graph represents those herds that never had a single BTSCC over 200,000 for the entire 2-year period. Likewise, the next lowest line represents all those herds that never had a single BTSCC over 300,000 in two years. Notice that those herds with consistently low BTSCCs do not have significant increases in BTSCC or BTSCC day-to-day variation during the warm summer months. High somatic cell count herds, on the other hand, do fluctuate more and are always higher in the summer months. Why? Studies have consistently shown that herds with low BTSCCs are doing an excellent job at consistently applying all the recommended milk quality improvement management practices. Therefore, when you are doing everything consistently well, you can have your cake and eat it too!

Figure 2

Figure 3