Selective dry cow therapy (SDCT) has become increasingly more popular on Irish dairy farms as January’s 2022 changes loom.

January 2022 will see the introduction of major changes to antibiotic usage on farms, with the aim of reducing antimicrobial resistance (AMR).

AMR in humans is being linked to antibiotic use in animals; hence why there is increasing scrutiny of the use of antibiotics in the agricultural sector.


SDCT involves only giving a teat sealer to a portion of the herd, with remaining cows receiving antibiotics and teat sealer.

Not every cow is going to be suitable for SDCT, so it is important that you develop a strategy that you can use to select cows that are suitable.

Animal Health Ireland (AHI) have developed a selective dry-cow strategy, which for many farms is a good starting point.

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

  1. Where there is good evidence of a low prevalence of infection – 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.

‘No one plan fits all’

What is important to remember is that it is not a case of ‘one plan fits all’, the thresholds should be developed on a herd-by-herd basis.

The threshold should be developed for your herd based off milk recording data and discussion with your vet and/or milk quality advisor.

What works for the herd down the road may not work on your farm, so developing a threshold to suit your farm is important.


The use of antibiotics will continue to play a role at drying off cows to treat infections that persist.

It is important that you are using the correct antibiotic to treat the infection, for cows that will receive an antibiotic at drying off you should identify the bacteria causing the issue and use the correct antibiotic to treat that bacteria.

You should avoid using the critically important antibiotics, ones that are important for human health.