Milk recording gives some crucial information when you are making culling decisions.  By assessing cell counts for individual cows you can track the pattern of mastitis infection over time, and pick only those with persistent infections for culling.

No-one wants to cull a good cow that is highly likely to cure her udder infection during the dry period. On the other hand there are good reasons to remove cows that will not be cured and are posing a risk to healthy cows within the herd. 

The best way to identify persistently infected cows in your herd is to list those with high cell counts for two consecutive lactations despite receiving Dry Cow Treatment in the intervening dry period.

Most infections will be cured with Dry Cow Treatment. So if cows have peak cell counts above 250,000 cells/mL for two lactations despite having Dry Cow Treatment in the period between, they should be considered persistently infected.

Some milk recording reports currently list cows with very high cell counts and give an enticing assessment of how low your bulk milk cell count would be without them. Don’t be tempted to focus on cows with very high cell counts in one season alone.  Many of these cows will cure if treated with Dry Cow.

If you have a high vat cell count and are thinking of selling cows for a ‘quick fix’, talk to your veterinarian or field officer about an overall plan. Just culling is never a cost-effective way to deal with the situation.

Image and caption
Which cows will you choose for culling?

Countdown Farm Guideline or Technote
Farm Guideline Introduction, 15

Keywords
Cull, persistent infection,  cell counts