Thirdly, antibiotic dry cow therapy can be expensive and reducing usage over time can be a cost saving. This should not, however, be a driving factor for starting but an added benefit.
Blanket Treatment versus SDCT
Eight of my clients adopted SDCT over the last three years and all are happy with how it went. They followed a careful plan and were initially nervous about the move but none have seen any reason not to continue the process. One farmer now treats only 10pc or less of his cows at drying off.
A very proactive and positive message from the dairy industry would be that this process of selective dry cow therapy is becoming the norm more than the exception. Blanket treatment of all cows at drying-off was accepted best practice for many years and was even one of the pillars of the 5-point mastitis plan. Changing this approach will not be easy, given that its introduction helped to reduce mastitis issues significantly in dairy herds across the world. Even the word blanket (treating every individual cow) suggests comfort, moving to selective treatment can be a challenge for many to process.
Nonetheless, I have seen first-hand how a new approach and some simple management can reduce antibiotic dry cow tubes without affecting the health of the herd. You will need a plan, so sit down with your vet and/or milk advisor to start planning for selective dry cow therapy:
Planning for SDCT
You will need to have certain things in order before you consider SDCT.
These are a must; to attempt SDCT without these essential steps is akin to playing Russian roulette with your herd. These simple steps significantly reduce the risks for you and your herd.
Herd SCC should be below 200,000 on average for the year. If your herd SCC is above this, then you are taking a risk in adopting SDCT and should be the first considering a SCC control plan.
Teat sealants used in all cows. The modern dairy cow, with larger yields, hugely benefits in the use of teat sealants to protect the quarter from introducing infections during the dry period. Care must be taken to do this as aseptically as possible.
Dry cow plan, especially around environmental hygiene in the dry period. When adopting SDCT, it is critical that we manage our dry cow environment to reduce infections during this period.
Pick cows that have consistently low SCC. I start the process with cows with SCC below 150,000 for the last six months. We need individual records so milk recording is essential when considering adopting a SDCT plan.
Clinical case records. It is strongly advised to use antibiotic dry cow tubes on cows that have had clinical mastitis in the last four to six months. This is why keeping clinical records of mastitis cases is very important.
Cows that have consistently low SCC <150,000 over the last six months and no incidence of clinical mastitis in this period are excellent candidates to start the process with.
Obviously you need individual cow records to properly implement this process. I'm often asked about using CMT (California Mastitis Test) alone but this is dodgy because the CMT will only pick up cows with SCC of greater than 450,000. Which means many can fall through the net.
Another useful part of the planning should be reviewing the mastitis cultures on farm to see what bacteria is prevalent. One exception to the rule is strep Agalactiae. If this has been diagnosed on farm, SDCT should not be considered.
In my opinion, a healthy udder with consistently low SCC and no clinical incidence in the last six months does not need antibiotic dry cow therapy.
Your job is to identify these cows in your herd and simply insert a teat sealant at drying off.
After implementing this process in many herds, we now treat just 10-20pc of the cows at drying-off. In line with our industry's proactive nature, we should all aim for this sort of approach.
Tommy Heffernan is a vet at the Avondale Veterinary Clinic, Rathdrum, Co Wicklow.