Selective dry-cow therapy — treating only certain animals with dry-cow tubes — may not be such a good idea, according to research published in the January Journal of Dairy Science.

During a study at the Institute for Animal Health in Compton, England, cows that did not receive dry-cow therapy experienced almost three times more new mastitis infections at calving than treated cows. These cows also had more clinical mastitis cases during the dry period than treated cows.

The findings confirm the need to treat all cows with dry-cow tubes at dry-off.