Questions about the use of antibiotics in agriculture are widespread. The use of antibiotics as therapy for animals that have disease is an important practice for humane husbandry. Wise use of antibiotics utilizing the best science-based information will help us protect and preserve the continued use of these products to help producers manage their herds to be healthy and productive.
From 1995 to 2015 the average Somatic Cell Count (SCC) for Dairy Herd Improvement herds dropped 100 points from 304 thousand cells/ml to 204 thousand cells/ml (Council for Dairy Cattle Breeding, https://www.cdcb.us/publish/dhi/current/sccx.html). Most of this drop occurred during the last ten years (since 2005). Similar numbers may be found for all milk sold through various federal milk marketing orders. Lower SCC is an indication of fewer incidences of mastitis and better cow health.
Routine use of dry cow antibiotic therapy widely adopted by dairy producers is one of the tools that have helped the industry obtain these improved levels of SCC while production per cow continues to increase. Dr. Pamela Ruegg and the UW milk quality website http://milkquality.wisc.edu/ has a discussion of selective use of dry cow therapy instead of traditional methods of treating every dry cow.
As more herds average under 250,000 SCC, and more individual cows within these herds are below 200,000 SCC at dry off with no history of clinical mastitis during the last 90 days prior to dry off, there are opportunities to reduce the use of antibiotics. Ruegg recommends the additional use of a quarter screening test such as the California Mastitis test and the use of an internal teat sealant for cows dried off without dry cow therapy.
Routine use of dry cow therapy for all cows has been a widely used and successful tool on dairy farms. Most likely as a dairy producer you are utilizing this tool and have misgivings about ever utilizing a different protocol. If there are ways to be more judicious with the use of antibiotics with no loss to animal well-being these methods need to be seriously considered.
Treating all cows at dry-off is a very simple and clear protocol for everyone involved with the herd to accomplish. To implement selective dry cow therapy requires a more complicated, but not impossible to understand protocol. We need to continually improve. We can do better than treating cows that are not likely to benefit from dry cow treatment but we could also err by not treating cows that are best to be treated.
Please go to the UW Milk Quality website http://milkquality.wisc.edu/dry-cow-treatment/ where there is a great discussion on this topic in easy to follow videos presented by Dr. Ruegg.
The attached illustration also on the website will help you make the best decision or individual cows and for your herd.
Figure 1. Decision Tree for Selective Dry Cow Therapy Programs