Cure rates are lower for older cows, infections of long duration, and when the cow-associated bacteria, Staph. aureus, is present.
Since chronically infected cows represent a source of infection for other cows, culling will help to protect healthy, young cows that are the future of the herd. However, culling is an expensive option and cell count problems will only be solved if follow-up measures are taken to prevent new infections.
Guideline 15 and Technote 15 provide practical and technical information on:
- A realistic percentage of the herd to cull for mastitis related reasons
- Considering culling a cow when you find her third clinical case for the lactation or she has high cell counts in two consecutive lactations
- Not using antibiotic DCT on cows which are going to be culled within the next 2-3 months