Benefits of practical approach to dry cow therapy protocols
© Adobe Stock Research and tighter rules on antibiotics use have given one Somerset dairy farm the push it needed to move away from blanket dry cow therapy and adopt a more selective approach. The result has been lower antibiotics use, fewer mastitis cases and no loss of milk quality.
The farm in question milks 280 cows through robots, averaging 12,923kg a cow a year. In 2022-23, the herd’s annual average bulk tank somatic cell count (SCC) was 58,000 cells/ml, showing that most cows were free of subclinical udder infection.
See also:Â 5 ways to improve udder health with dry period management
About the author
Anna Hares, director of Shepton Vets, explains how herd health data and scrupulous hygiene at drying-off helped cut one herd’s clinical mastitis rate by 43%. Â
Even so, the annual clinical mastitis rate was running too high, at 37 cases in every 100 cows.
As the herd vet, I worked with the team to build a practical protocol they could follow confidently.
One staff member took on most of the drying-off work, which helped with consistency.
We used the hydraulic foot crush so cows could be properly restrained, allowing teats to be cleaned thoroughly immediately before infusion. This reduced the risk of contamination when applying teat sealant.
No foot-trimming occurred during the drying-off process.
Treatment thresholds
Good decisions depend on good records. Clinical mastitis history and cell count data were made easy to access, so cows needing antibiotics were clearly identified.
The herd’s initial threshold for selective dry cow therapy was cows with a cell count above 120,000/ml, and heifers above 100,000 cells/ml, in any of the last three recordings before dry-off.
Any animal with a mastitis case during that lactation also received antibiotics, as did cows still giving more than 30 litres/day at dry-off.
I demonstrated how to infuse teats in the correct order and ensure teat ends are sealed properly. The member of staff then practised the technique under my supervision.
Hygienic teat preparation is especially important in animals not receiving antibiotics at dry-off, as the introduction of bacteria during this process can lead to toxic mastitis several days later.
Written protocols were kept simple and easy to refer to, and progress was reviewed regularly so the system could be refined as confidence grew.
Careful management after treatment
Recently dried-off cows were checked closely, housed in a very clean environment and fed ration with a low energy density for 48 hours to help reduce milk production quickly.
Staff watched carefully for swollen quarters, and rumination monitor data helped pick up any sick cows early. Problems were few, cases were treated promptly and, importantly, no cows died from mastitis after drying-off.
The results have been encouraging. Bulk tank SCC have remained low, averaging 73,000 cells/ml over the past year, while the clinical mastitis rate has fallen from 37 to 21 cases for every 100 cows a year.
Over the same period, 75% of the herd received teat sealant only at dry-off, cutting antibiotics use significantly.
Overtreatment increases future mastitis risk
UK research has demonstrated that administering dry cow antibiotics to healthy cows with low somatic cell counts (SCC) actually increases their risk of developing clinical coliform mastitis (specifically E coli) twelvefold in the subsequent lactation (Bradley et al, 2010).
This occurs because broad-spectrum antibiotics eliminate the udder’s natural, protective bacterial flora, creating an environment that pathogens quickly exploit.
By reserving intramammary antibiotics at drying-off exclusively for cows with established infections (identified via SCC records, past clinical mastitis data and teat-end risk factors), low-SCC cows maintain the beneficial bacteria in their udders through teat sealant use alone.