The dairy control report indicates mastitis

A perspective on how a dairy control report is a useful tool for herd management Displays how good record keeping and interpretation benefits the farmer in the end

"Mastitis and Somatic Cell Count" was the theme for the 5th Quality Milk Forum, organized by PLM and Pharmacia Animal Health. A follow-up of the various subjects discussed at the Forum is brought to you monthly by PLM. This month we will have a close look at the Dairy Control Report and learn how to determine which cows are infected. Elisabeth Trocherie, Dairy Control Engineer in the province of Finistère, Western France, explains what we can expect to learn from the data.

A visit to a dairy farm will help us understand how the Milk Control report relates to the daily work with the herd. After a thorough inspection of the barn and its layout, dairy farmer Marcel Léauté and Dr. Catherine Journel, veterinarian, return to the farm office. Together they will take a close look at the Dairy Control report to identify contaminated cows.

 

The Veterinarian:

Please let me have a look at your Milk Control binder with the results listed by individual. Give me the last sheet of the control report, and I would also like to see the register of medical treatments. For each cow, we will check the medical treatment and the current somatic cell count. Based on that, I can tell you if the mastitis cases you treat are actually cured or not.

The Dairy Farmer:

I take down everything: the name of each cow, the date of the treatment, the infected quarter, the name of the product, the with-holding period. The dairy technician insisted that I should join their quality program “Agro Confidence”.

The Veterinarian:

It is in everyone’s interest that all medical treatments are recorded. Yet the first winner is you. You will have complete control of the health status of your herd. Based on that information, you can make the right herd management decision- for example when a cow is due for culling. You get a better view of the efficiency of the treatments.

Marcel leaves the scene and comes back after a while with binders and reports. Catherine takes a close look at each document.

The Veterinarian:

I have gone through the last five reports of control data, until end of May, listing the cows that were infected prior to that date. Six of your “cell count cows” were infected right through two lactation periods. And fourteen were infected during the current lactation!

The Dairy Farmer:

If I understand you right, you say that half of my herd is made up of “cell count cows”. But I don’t have twenty heifers ready to replace them! I will have a hard time getting out of this.

The Veterinarian:

I didn’t say that you have twenty cows to eliminate. To start with, I think you will see a certain number of cows that cure during the dry period. Your cure rates are 73%, which is really a very good result.

The Dairy Farmer:

That makes me feel better! I won’t have to sell off half of my herd after all... So much the better, in view of the current price level for meat. Look here, this is the note book where I record all mastitis cases with details on the treatment.

The Veterinarian:

These notes are interesting. I can compare two case categories: those that have been treated as soon as you identified a mastitis infection, and those receiving treatment based on a reported high cell count. In the first case, you have identified a clinical mastitis that will most probably be cured by the treatment. The second case is a sub-clinical mastitis that you treat with an intra-udder product, totally inefficient in this context. The chance of a successful cure is low in this case, knowing that the bacteria has been present in the udder for quite a while. By carefully checking the first jets of milk, more cases of clinical mastitis will be identified at an early stage, which means that they can be successfully treated right from the start. The improved health status is the key to improved income!

The Dairy Farmer:

While you calculate, I will make coffee. It is soon milking time. I cannot let my cows wait!

Marcel prepares the coffee, Catherine goes through the list of treated cases in relation to the actual healing.

The Dairy Farmer:

Why does the dairy controller indicate cows with suspected infection even though their cell count is on the downturn? That is the case for Nirvana and Mascotte.

The Veterinarian:

You must be careful in interpreting a single cell count result. An infected cow does not necessarily show a high cell count every time. The first report might indicate 250,000 cells/ml, the next time peaking at one million, and going down again to 200,000 in the following sample. She will be reported as “suspected” as long as she has not produced a low cell count for three samples in a row.

Elisabeth Trocherie, Dairy Control Engineer in the province of Finistère, Western France, explains what data are relevant when classifying the cows, how to calculate the rate of new infections and the cure rate.With “problem cows” the rate of new infections and the cure rate are key values. The classification of the cows as “infected”, “suspected”, or “healthy” helps us to get an overview in herd management issues.
And now, back to the kitchen.

The Veterinarian:

We talked earlier about the twenty cows in your herd with cell count problems. Six of them have been infected during two lactations or more. Another 14 cows were infected during the current lactation. In the past, eleven cows out of these 14 seem to have suffered from sub-clinical mastitis. The treatment you used at that time hasn’t given much result. According to your files, you have now successfully treated eleven of the cows that were identified with clinical mastitis. The remaining three confirmed cases of clinical mastitis have been treated without success, and they have now become “cell count cows”. This represents a 75% cure rate for clinical mastitis (11 cured out of 14 clinically infected cows treated). That is very good.

The Dairy Farmer:

It is true that I have had good results with the cows where I could identify the clinical mastitis. The infected cows had a swollen teat, easy to see. That is what happened to Noisette: I thought she might lose the infected quarter. My regret is that I don’t manage to identify the other cases.

The Veterinarian:

That is true. The others represent cost. They don’t heal because you treat them too late. I have not invented the figures: you have treated 14 cows, but only 11 with clinical mastitis. The other 3 did not cure and the treatment cost was wasted. Not to mention the value of the milk that you have had to throw away – do you think that is profitable business?

(The original article in French was published in PLM (Production Laitiére Moderne), April 2002)

Related Links:

Home page for the magazine Production Latiere Moderne

University of Nebraska: Dairy 10 Point Quality Control Program- Mastitis Treatment Records

University of Nebraska: Basic Principles of Mastitis Control. A useful guide for a mastitis control program.