Selective dry cow therapy
While many of us prepare to dry off for autumn, it seems a prudent time to discuss selective (part-herd) dry cow therapy.
Worldwide, we are experiencing an antimicrobial resistance (AMR) problem whereby years of incorrect or inappropriate use of antibiotics has caused bacteria that were previously susceptible to antibiotic treatments to become resistant, rendering our treatments ineffective and posing significant risk to human health.
Globally, human and animal health teams have a responsibility to develop effective strategies to help slow the progress of AMR and reduce the risk to our communities. Farmers too, have an important role to play.
In Ireland, new regulations mean antibiotics can no longer be used as a preventative, and therefore blanket dry cow therapy is no longer allowed. Vets will not be able to prescribe dairy farmers antibiotics without the necessary proof. Dry cow tubes can only be used to treat existing intra-mammary infections, and farmers will need to provide evidence via milk recording and herd health data that they have a requirement for antibiotic usage on their farm.
The New Zealand Vet Association has set similar targets by 2030, and the Netherlands banned blanket dry cow in 2012.
Here in Australia, where mastitis control (including dry cow therapy) accounts for about 66 per cent of antibiotics used on dairy farms, Dairy Australia has supported the Australian Veterinary Association and Animal Medicines Australia to develop Antimicrobial Prescribing Guidelines for Dairy Cattle.
In my mind, it’s important we don't see these changes as “drugs being taken away from us” but rather as “making sure we still have drugs available when we really, truly need them”.
Regardless of what our regulations are here in Australia, antibiotics shouldn’t be relied upon where improvements in management could achieve the same outcome.
So, how can we do our part? Selective dry cow therapy is a good place to start.
Although it won’t be appropriate for all herds, many farms are well-placed to implement a selective dry cow program, and already a number have voluntarily moved away from blanket treatments.
Selective dry cow programs work best when herds have:
- A low bulk milk cell count year-round.
- Regular herd testing, or in-line milk meters, with a test ideally in the last month before dry-off.
- Comprehensive clinical mastitis and treatment records.
- Regular culturing of clinical cases to identify causal agents of mastitis, and sensitivity testing where required to confirm appropriate antibiotic treatments.
- Good dry cow and calving time management, with low clinical case rates.
- No history of Streptococcus agalactiae (strep ag) mastitis.
- Well-trained and proactive staff, and a good farm advisory team.
- Attention to detail in relation to shed, yard and general hygiene (including when administering treatments and internal teat sealants).
Cows with an average individual somatic cell count of less than 100,000 for the year with no test more than 200,000 and no cases of mastitis during the current lactation period, would be eligible for selective dry cow therapy, whereby only an internal teat sealant is administered hygienically at dry-off.
The World Health Organization has classified antibiotics into three categories based on their importance to human health, and subsequently an importance rating or ‘traffic light’ system has been introduced in many countries, including Australia.
Under the Australian Dairy Sustainability Framework, the industry has committed to the responsible use of antibiotics, including using antibiotics of critical importance to human health only in exceptional circumstances where no other alternative exists. We still have a duty of care to protect the health and welfare of our animals.
If you’re interested in exploring how selective dry cow therapy might be implemented on your farm, make sure you have the appropriate records available (including treatment records, culture results and herd test or milk meter data) and get together with your vet and field officer for a dry cow consult.
For further information and resources (including a great podcast link), visit: https://www.dairyaustralia.com.au/animal-management-and-milk-quality/antimicrobial-stewardship#.YbET27UzZPY
Lucy Collins is completing her Dairy Residency with the University of Melbourne. She works as part of the ProDairy veterinary team for Apiam Animal Health, and alongside her partner on his family’s dairy farm in south-west Victoria. She is a 2021 Nuffield Scholar supported by Gardiner Dairy Foundation.