Keeping Somatic Cell Count (SCC) on track in late lactation
What can dairy farmers do to mitigate SCC rises in late lactation and prepare cows for a healthy dry period? Padraig O’Connor, Dairy Technician, shares some key tips.
Maintaining a low somatic cell count (SCC) is one of the most important aspects of milk quality and overall herd health. SCC provides a direct indication of udder health and the level of infection in the udder. High SCC levels not only reduce milk yield and quality but can also result in milk price penalties, higher treatment costs and long-term production losses.
In dairy cows, high SCC is typically caused by bacteria entering the teat canal, leading to mastitis. During late lactation, SCC often begins to rise on some farms, thereby reducing milk yield, and increasing the risk of spreading infection.
So, what can dairy farmers do to mitigate SCC rises in late lactation and prepare cows for a healthy dry period?
The ‘big-ticket’ items for controlling mastitis in your herd, regardless of the time of year, are:
1). Routine milk recording and acting on the results
- Regular milk recording identifies problem cows and quarters early (minimum of 4, optimum of 6 per year)
- Promptly act on results – segregate, treat, or cull where necessary.
2). Milking machine maintenance
- Ensure the milking machine is serviced regularly and working correctly.
- Poorly functioning milking machines can damage teat ends, increasing the risk of infection.
3). Good milking routine
- Cows should be clean before milking.
- Use nitrile disposable gloves to reduce bacterial transfer.
- Post-milking teat spraying with the correct volume (15 ml per cow per milking) ensures teat skin health and helps reduce infection.
4). Changing liners
- Replace liners every 2,000 milkings or every 6 months (whichever comes first).
- Worn liners compromise teat health and harbour bacteria.
Additional measures for reducing SCC in late lactation
While the big-ticket items are a given, additional measures become particularly important in late lactation:
- Segregating cows
- Milk clinical mastitis and high-SCC cows last to avoid spreading infection to healthy cows if practical.
- Culling chronic cases
- Persistently infected cows are a continuous source of infection and are also spreading infection. These need to be culled to improve long term herd health.
- Cluster hygiene between milking cows
- Dip clusters in a peracetic acid solution (3 ml per litre of water) after milking a high-SCC or mastitis cow. This will help break the infection cycle and reduce cross-contamination risk.
- Use of automatic drafters
- Draft out high-SCC cows and milk them last if an automatic drafter is in place.
- Quarter testing
- Use the California Mastitis Test (CMT) to identify individual quarters with a high SCC. Depending on the results, options include targeted antibiotic treatment in consultation with your vet or drying off the affected quarter.
- Cluster flush systems
- Consider installing an automatic cluster flush or cleansing system in herds with persistent and ongoing SCC problems. These systems rinse and disinfect the cluster after each cow is milked, helping to reduce the spread of bacteria between cows.
- Culture and sensitivity testing
- Collect a sterile milk sample from infected quarters for laboratory analysis to identify the bacteria causing the infection. Discuss the results with your vet to determine the most appropriate antibiotic treatment for mastitis during lactation and for dry cow treatment.
Conclusion
Keeping SCC on track in late lactation requires a consistent approach to milking hygiene and identifying and managing high SCC cows. By focusing on these areas, farmers can help break the cycle of infection, improve udder health and maintain milk quality. Good SCC control is not only about treating mastitis, it’s also about prevention, consistency and attention to detail. Taking action before cows are dried off can deliver long term benefits for milk quality, herd health, animal welfare and farm profitability.