The practical applications of the DeLaval cell counter DCC
Peter Edmondson
Shepton Mallet Veterinary Group
Allyn Saxon Drive
Shepton Mallet
DeLaval launched the Delaval cell counter DCC which is a portable cell count testing machine in September 2004. I have been using it in the practice since then and find it an invaluable piece of equipment.
The testing procedure is very simple with an individual cassette required for each test. The nozzle of the cassette is put into the milk sample to be tested and the plunger depressed. The cassette is inserted into the machine and the run button pressed. In less than one minute a numerical result appears. The testing system could not be easier and the use of a single cassette per test means that there is no risk of carry over of milk between samples.
When we originally started to use the machine we had some idea where it would be used but were unsure about take up. The great advantage is that we are able to give an instant result so the farmer who comes in with 3 samples can wait three or four minutes while someone carries out the test and gives him the result there and then.
There are no postage costs, package problems, no minimum number of samples required, no samples getting lost in the post, no waiting for results to come back on the fax machine and then be reported to the farmer. The real advantage of this machine is its accuracy, ease of use and instant results.
Since we told farmers that we can measure cell counts, more and more samples are coming into the surgery. This has a beneficial effect for farmers as it’s easy to get test results but has an additional benefit to us as it allows us to discuss mastitis problems with our dairy clients.
Farms, get bulk tank results from their milk buyer on a weekly basis and individual cow cell count results on a monthly basis. Results from the milk buyer often follow two or three days after the sample was collected and so often we are waiting 10 days before we can find out what is happening to the bulk tank results.
We now encourage all farms with cell count problems to send bulk tank samples into the practice on a daily basis so that we can check on progress. Some farmers find these results useful as it can show a difference between milkers. Milkers who are not good at detecting mastitis tend to have higher cell counts as they may milk cows with clinical mastitis into the bulk tank. This can increase the bulk tank cell count and high results allow us to go back and show them there is a need for them to improve mastitis detection.
Farmers also can have the reassurance that progress is being made, or not, on a daily basis. It has been useful to have been able to compare our results to those of their milk buyer if there is any dispute. Daily testing of bulk samples in problem herds allows us to have an early warning system. If the herd cell count is rising we can go in and take more radical action earlier than having to wait for the weekly result from the milk buyer which may have been taken on a day when the herd cell count was low.
Figure 1. shows the daily bulk tank cell counts for a problem herd whose cell count was over 300,000. It can be seen that there is variation between daily samples but that the trend is constantly down, this has allowed the farmer considerable assurance that his problems are being resolved. The three milk results tested by the milk buyer tell a different story with no apparent improvement until the trial sample was tested.
When individual cow cell count results come back on the monthly NMR recording some cows may have a high reading. A sample can confirm if this animal is still high. Some farmers have taken quarter samples to identify which is the persistently high cell count quarter and dried this quarter off.
Tests have been used following treatment to ensure that the cell count has returned to acceptable levels before it enters the bulk tank. Farmers could use the CMT test but it should be remembered that the CMT test is not particularly accurate if the cell count is below 500,000. If the cell count is marginal and is close to the penalty band he cannot afford these cows pushing them over the limit.
There are still many farms which don’t carry out monthly cell count recordings and we can use our DCC tester to screen high risk or suspect cows. This has proved very popular with clients who are unable or unwilling to carry out a whole herd screen due to time constraints but find it relatively easy to sample selected cows. This can allow immediate decisions to be made on problem cows, but of course there could still be other high cell count cows in the herd that are undetected.
In herds with no individual cell counts it can be useful to sample the quarters from cows with recurrent episodes of mastitis as these are often persistently high cell count cows. This can assist in helping advise on culling or alternative decisions.
There are also other opportunities where it could be used. Dairy companies could have a unit on tankers for daily testing of bulk milk as a management tool. This could be used in addition to the lab tests for determining milk quality and payments. Farmers could be invited to pay for these tests which could provide excellent information for all the reasons discussed above in relation to Figure 1. The result could be written onto the milk volume print out left on farm for an instant result.
The great advantage of the DCC tester is that it brings us more in contact with our dairy farmers and that we are in a better position to be able to advise. Its ease of use could not be simpler and all members of our practice carry out testing.
The price of the test to the farmer is not cost sensitive, as the benefits outweigh the cost. We seem to be carrying out more and more tests for a variety of reasons for our farmers. The economics of the machine are probably cost neutral but the real benefit is that is strengthens the link between farmers and the practice and also allows us to be more involved in mastitis problems and work on our dairy client farms.
|
