More than 300 cows from four different research herds — Iowa State, Kansas State, Cornell University and the University of Guelph — were enrolled in a study to examine the effect of milk production and management factors on drying off dairy cows.

At two weeks prior to dry off, at dry off and at freshening, each animal received a teat-end score, an udder- involution index and quarter milk samples were collected. After freshening milk sample results were evaluated to determine the rate of new infections. Preliminary data show that the risk of intramammary infection increased if a cow had at least one teat end that had moderate to severe hyperkeratosis and was cracked prior to the dry period.