by Peter Edmondson
The author is a veterinarian who runs UdderWise-Global Mastitis Solutions, United Kingdom.
I just don't know why my cell count has gone through the roof. It was 250,000 three months ago, and it's now 500,000 and rising fast. I need your help." These were the comments from Mike, a desperate farmer who was facing severe financial penalties for his herd's high cell count and the risk of not having his milk picked up in two months' time if the three-month payment average cell count was not brought back under 400,000.
Mike milks 250 cows and has been an organic farmer for over 10 years. There are a number of organic organizations within the EU which have slightly different dairy standards. The organic rules are stringent about antibiotic use. But unlike the U.S., some organic farmers within this group of nations can use blanket dry cow therapy if they can justify that this is necessary.
A few years ago he had cell count problems and these were resolved, and part of this involved the use of blanket dry cow therapy.
At the end of last year, Mike received a letter from the organization which looks after his organic standards. They were not happy about the continued use of blanket dry cow therapy. Mike decided that, as his cell count was around the 200,000 level, he would just stop its use altogether. He never consulted his vet about this.
Wrapped with emotions
In Europe, there is great interest in antimicrobial resistance and responsible use of antibiotics. This is being driven by various groups, including supermarkets and milk buyers. I remember talking about selective dry cow therapy at a meeting in Europe several years ago, and it got a very frosty reception.
I could see one person at the back looking very agitated, and he eventually stood up and started to talk. His youngest daughter ended up in the hospital with a severe infection that was resistant to all antibiotics. He described the pain and anguish watching his daughter going downhill and wondering if she would live. Fortunately, she survived. This person was a veterinarian, and after this incident he totally changed his practice's attitude toward antibiotic use.
Arla Foods is one of the largest milk buyers in the UK, and in October 2015 it required all farmers to start working toward selective dry cow therapy. After April 2017, its producers will no longer be allowed to use blanket dry cow therapy.
A cure for high counts
Blanket dry cow therapy was introduced in the early 1970s when herd cell counts were really high. At this time, the UK average cell count was 550,000, and Staph. aureus and Strep. agalactiae levels were very high. UK average cell count is now below 200,000, and Strep. agalactiae is rarely seen. In 1968, there were 45 clinical cases of Staph. aureus per 100 cows per year; this has been reduced to two.
The majority of cows are free of subclinical mastitis, so using antibiotics in these healthy cows can no longer be justified. Teat sealants at dry-off help reduce dry period infections, and this reduces clinical cases. Selective dry cow therapy is good for everyone.
Reversing the trend
So back to Mike; he contacted me just before I was going away on vacation, and I was starting to put things in order for my return to work. When Mike told me that he had lost over $15,000 in cell count penalties the previous month, I rescheduled other work and made time to go and visit. The aim was to stop any further spread of infection, protect the healthy cows and to crash the herd cell count to limit any future financial penalties.
I arrived on-farm and spent a couple of hours discussing the cell count problem and asking lots of questions about his mastitis management. Then I went into the parlor to spend time watching the cows being milked.
The herd stopped postmilking teat disinfection last year and only started again a couple of weeks before my visit. Failure to postdip accelerated the spread of infection. I explained the importance of dipping every cow after every milking to help kill the bacteria transferred from cow to cow during milking.
I watched them using handheld teat sprayers. It was clear that this was only covering those parts of the teats facing the spray nozzle. I showed the front parts of the teats to Mike and the milkers. They were getting about 50 percent teat cover, so we agreed to start postdipping with teat dip cups instead.
Clusters were dipped in buckets of water, and these were very dirty. I think this was doing more harm than good as they were introducing fecal contamination into the liners. We changed the routine so that clean buckets of peracetic acid would be used, and these were to be changed once the solution got contaminated. Various other changes were also made.
Mike is not on a regular cell count recording scheme like DHIA, but he had two recent sets of individual cow cell counts. We split the herd, putting the highest cell count cows into a separate group, which were milked last. Their milk was fed to the bull calves. We also dried off problem cows that were toward the end of lactation. This helped reduce the herd cell count.
We agreed on a treatment plan for the dry cows about a week before they were due to calve as none had received dry cow therapy. We had to stop infected cows from calving back into the herd and pushing up the cell count.
This is always a challenging situation, and it was important to manipulate the herd cell count so that we could avoid another month with really high cell count penalties. We couldn't work out the percent contribution to the bulk tank of individual cows as there was no way of measuring individual cow yields.
Our measures worked, and the cell count penalties that month were reduced by 80 percent. Our mastitis plan continues, and we are seeing a slow and steady reduction to where we need to be. Once the herd cell count reduces further, then we can move to selective dry cow therapy following carefully considered and agreed guidelines, but this will not be for some time yet.
The key learning outcome from this expensive case is to always talk to your vet before you make major changes; we all want the best for you and your cows.