Dairy cows that are only teat-sealed at drying off can have similar mastitis rates and somatic cell counts to cows that are treated with antibiotic tubes, a NI-based study has found.

Almost 400 cows at the Agri Food and Bioscience Institute (AFBI) in Hillsborough, Co Down were part of the two-year study into selective dry cow therapy (SDCT).

Cows that had a somatic cell count over 200,000 cells/ml in any of the last three monthly milk recordings, or had a case of mastitis during the last three months, were deemed “high-risk” and were treated with antibiotic tubes and teat sealants at drying off.

Cows were “low-risk” if their cell count was below 200,000 cells/ml and they did not have mastitis during the previous three months.

As part of the study, half of the low-risk cows received the same treatment as high-risk cows at drying off. The other half received no antibiotic tubes and were teat sealed only.

These findings suggest that SDCT can be adopted with low-risk cows with no negative implications for udder health

The AFBI researchers found that both groups of low-risk cows had similar incidence rates for mastitis in the following lactation at around 0.2 cases/cow.

Low risk cows that were dried off without antibiotics had an average cell count of 80,000 cells/ml, whereas average cell count in the antibiotic treatment group was 75,000 cells/ml.

Cows in the high-risk group (all tubed and teat sealed) had an average cell count of 219,000 cells/ml and mastitis incidence rate was 0.6 cases/cow.

“These findings suggest that SDCT can be adopted with low-risk cows with no negative implications for udder health or performance during the subsequent lactation,” the AFBI researchers concluded.