Most dairy farms are already seeing the benefits of selective dry cow therapy. With increasing pressure from milk buyers and the general public to reduce antimicrobial usage, this article looks at what is often the main contributor to dairy antimicrobial use, namely clinical mastitis, writes David Jackson BVetMed MRCVS of Westpoint Farm Vets.
- Sampling; know your enemy!
It is good practice to sample every case of clinical mastitis. Take and freeze a sample from every case before treatment (labelling it with cow number, quarter and date). If treatment fails or the mastitis recurs, there will be a pre-treatment sample to which you can refer. Your vet will advise you on how to take a clean sample. Samples can be cultured and/or tested with PCR (Polymerase Chain Reaction), increasing the chances of a meaningful result.
Once we know what organisms are responsible for your mastitis, we can advise on appropriate husbandry changes and treatment. It may also guide decisions on drying off and culling.
- Non-steroidal anti-inflammatory drugs (NSAIDS)
NSAIDs (e.g. meloxicam, keloprofen) improve treatment success and reduce the recurrence of clinical mastitis, even in mild cases. If you are not already doing so, discuss with your vet the merits of using NSAIDs in mastitis treatment.
- Chronic mastitis and treatment failures
Discuss problem mastitis and high cell count cows with your vet. A few problem cows can account for a lot of antimicrobial usage. Has she had multiple cases this lactation? Has she not cured after treatment? These are the animals we may send off a milk sample for or they may be candidates for early drying-off or culling.
- Injectable antibiotics in mastitis
There is very little evidence to support the use of injectable antibiotics in mastitis treatment. The only animals likely to benefit are those which are systemically ill (e.g. severe E.coli mastitis) and even then evidence for the use of injectable antimicrobials is limited. Treatments such as fluids (oral/intravenous) and anti-inflammatory drugs are of more benefit. If still routinely using injectable antibiotics for mastitis treatment, revise your protocols with your vet.
- Vaccines
Startvac is a vaccine against E.coli, Staph. aureus and coagulase negative Staphs (CNS). For herds with significant levels of these types of mastitis, it can demonstrate a significant cost benefit by reducing the mastitis severity and decreasing milk losses.
UBAC is a new vaccine against Strep. uberis mastitis. This is one of the most common forms of mastitis and can be responsible for recurrent or hard-to-cure cases. The vaccine has been proved to significantly reduce the incidence of Strep. uberis mastitis.
Use of these vaccines should only be considered after a vet has assessed farm suitability. Milking routine and/or husbandry changes are often required to get the full benefit from them.
Where do I start?
A good starting point is to complete an AHDB mastitis control plan for your farm. This is a wide-ranging farm audit concentrating on mastitis and udder health that helps focus on potential problem areas so appropriate advice can be given.
Annual reviews of your health plan with your vet, as well as medicine courses such as Milksure, are important to ensure your team remains up to date with best practice.
Summary
Nobody wants to compromise animal welfare by denying cattle the treatment that they need. The latest initiatives are about thinking twice about the antibiotics we prescribe and deciding if they are:
- Necessary
- Appropriate
- Being used correctly.
Antimicrobial resistance and residues in milk are a real concern for the reputation of our product. Acting now meets these concerns head on and also reduces the pressures on finances and time caused by high levels of clinical mastitis in a herd.
Pictured: Sample pots suitable for milk. Plain pots (right) are suitable for traditional culture or PCR testing but must be refrigerated or, if not being tested immediately, frozen. Preservative pots (left) are only suitable for PCR testing but require no cooling or freezing.
