Dry Cow Therapy
Selective Dry Cow Therapy;
Is your dairy good enough to enjoy the benefits? By Michael Cox for American Dairymen Magazine
ntibiotic use at dry-off is common practice across dairy farms. USDA National Animal Health Monitoring System surveys suggest that over 90 percent of operations use antimicrobial products at dry-off, with blanket treatment of all cows most common. Selective Dry Cow Therapy, (SDCT) involves identifying and treating only certain high-risk cows/quarters at dry-off, and while the process has seen only moderate uptake among dairymen, many early adopters are finding positive outcomes. The rewards of lower labor costs, lower product costs, decreased risk of antibiotic resistance and stable somatic cell count levels in subsequent lactations are enticing more dairymen to consider SDCT, despite it’s ‘risky’ perception. Although the advice from experts is still relatively mixed, as seen from the varied opinions from the National Mastitis Council symposium earlier this year, there is still scope for well-managed dairies to make huge savings and maintain current milk quality standards through SDCT. Dr. Andy Johnson, dairy consultant based out of Wisconsin and past-President of the National Mastitis Council, believes that a change in mindset is needed before more dairymen take-up SDCT. “In my 40 years in the dairy industry we’ve been used to the mantra of blanket cow therapy at dry-off, but we’re in a different place now and
SDCT is showing some wonderful results,” Johnson says. Strep and Staph borne mastitis cases may have been more prevalent in past decades, but modern animal health and facility standards have greatly reduced clinical cases in well-managed dairies, resulting in less requirement for blanket cow therapy today.
Among Johnson’s client base, eight large dairies have transitioned away from blanket cow therapy recently. “Over the past two and a half years I’ve been working with eight big dairies that started using SDCT and have had excellent success, with no increase in clinical mastitis cases in the next lactation,” Johnson says. Half of the eight dairies have average bulk tank somatic cell count levels of 125,000 cells/ml or less, with the other four dairies regularly achieving 100,000 or less. All eight herds have a rolling average of 90-100lbs of milk per cow. It is possible that SDCT is best suited to ‘good’ herds with less than 150,000 cell counts, as these herds pose less clinical case risk compared to herds with 400,000 or greater bulk-tank cell counts. Low cell count herds usually have only environmental and gram negative caused mastitis cases, which respond well to treatment during lactation. Selection of the correct cows/ quarters to treat, and which not to * Continued on page 12