The Mastitis Game Plan!
New industry recommendations for making drying off decisions aiming at less antibiotics, lower cell counts and more milk! Drying off is the time to set up the farm for less mastitis and a bulk milk somatic cell count (BMSCC) consistently under 150,000 cells/mL in the next season.
A recent Dairy Cattle Vets (DCV) roadshow supported by the National Milk Quality Advisory Council (NMAC), the New Zealand Veterinary Council (NZVC) and DairyNZ highlighted the importance of good drying off decisions for both the cows and the dairy industry. The key messages were:
New research shows that very few New Zealand (NZ) herds justify whole herd antibiotic dry cow therapy (DCT).
The industry accepted criteria for vets to prescribe whole herd DCT are limited to herds with a mean BMSCC, until end of seventh month of lactation, of greater or equal to 200,000 cells/mL AND when the mean monthly BMSCC has increased by greater than 40,000 cells/mL between the sixth and seventh month of lactation.
All cows should be protected at drying off with an internal teat sealant (ITS).
DCT treatment decisions should be made at the individual cow level using criteria decided and agreed upon between the Vet and Client.
The new SmartSamm guidelines recommend that cows eligible for DCT include:
Cows treated for clinical mastitis in the last dry period or in current lactation.
Cows or heifers with one or more high individual cow SCC above an agreed threshold (ie. between 150,000 and 250,000 cells/mL) in the current lactation.
Cows with a positive rapid mastitis test (RMT) result (ie. one or more glands with a trace result or above) close to dry off.
Cows with other risk factors. These may include:
Cows over four years old and milk production over 15L at the last herd test of lactation
Cows with visible teat end damage
All other cows may be treated with a non-antibiotic ITS.
This provides an opportunity for Vet and Client to discuss the agreed threshold for DCT at a milk quality consult and/or review. Together, using individual cow SCC results from four herd tests plus any diagnostic test results, decisions on selective dry cow and culling can be made, for example:
Chronically infected Staphylococcus aureus (S. aureus) cows should be culled based on high SCC (ie. greater than 300 to 500,000 cells/mL over three herd tests) and Mastatest results.
The best time to cure low SCC S. aureus infection is during the dry period when treatment with long-acting DCT should cure 65% to 70% of cases.
All cows should be protected with ITS.
Aside from the above support in making decisions on which cow to treat with what, we can support the process practically, with our Technician Team and/or Vet(s) performing the administration of products at drying off for you. We can also assist with training and upskilling of your farm staff so don’t hesitate to give us a call – we’re here to help! In addition, look out for the upcoming AgriHealth Mastitis Farmer Roadshows… our area events are on 16th May 2025 in Feilding (Manfield Park Stadium Suite 59) at 10.00am and Dannevirke (Tararua REAP Hula Room, 15 Gordon Street) at 1.00pm.