During the recent MSD webinar ‘Udder Health – The Past, The Present and The Future’, Peter Edmondson spoke about the challenges and opportunities for selective dry cow therapy (SDCT).

Peter Edmondson spent 35 years in dairy practice before forming UdderWise, a veterinary consultancy specialising in mastitis, milk quality and residues. Peter works with dairy farmers, vets and pharmaceutical and dairy processors around the world.

Peter stated that in the 1970s, the average cell count for a cow was 500,000ml, which lead to the introduction of the five point plan:

  • Culling;
  • Post-milking teat dipping;
  • Milking machine;
  • Treat clinical cases;
  • Blanket dry cow therapy.

In 2020, the national herd achieved average cell counts of 178,000ml – with the target being 150,000ml.

The need to plan

Peter explained the importance of needing to plan when it comes to making a decision regarding SDCT: ”All herds are different, it is important to consult with your vet to develop a plan for your farm.

”Every farm has a different parlour, different winter housing and different management practices – because of this, one plan does not fit all,” he said.

Mastitis background information

Peter explained that farmers should identify the following three points regarding cow udder health:

”What are the issues on the farm – it is important to talk to your vet about mastitis/ somatic cell count (SCC) issues,” he said.

”What are the causes of mastitis / high SCC issues on the farm; the mastitis origin from during the lactation or the dry period?

”Is the mastitis clinical or subclinical; is the mastitis being caused by the environmental factors, or does the herd have an issue with contagious mastitis?

”This is where using milk recording data is important, it allows you to build a profile for each cow in your herd and identify possible issues,” Peter added.

”Looking to the future, farmers should be consulting with their vets when looking at milk recording data – this will allow farmers to select the correct treatments for individual cows.”

AHI Strategy

Throughout Peter’s presentation, he outlined the Animal Health Ireland (AHI) selective dry-cow strategy, stating that: ”It is a good starting point for you to select suitable cows and develop a plan for your herd.

”But it is important to remember that the thresholds should be developed on a herd by [the] herd basic [philosophy] ‘one plan does not fit all‘.

”Each herd should develop the threshold based on their herd and the data collected from milking recording,” he said.

For example, AHI selective dry-cow strategy may be considered in herds:

  1. Where there is good evidence of a low prevalence of infection, e.g. a bulk milk SCC consistently below 200,000cells/ml, a dry period new infection rate of less
    than 10%;
  2. Where good practices and high levels of hygiene can be achieved at drying-off, throughout the dry-period and at calving;
  3. Where regular milk recording is carried out, with at least one recording in the last month prior to drying-off;
  4. Where the herd keeper is willing to engage with their veterinary practitioner in decision-making around their dry-cow treatment programme.