Evaluation of a Hygiene and Dry Period Therapy Program for Mastitis Control

Abstract

In two trials half of the cows were subiected to a postmilking test dip and and dry period therapy of all quarters while the other half were untreated controis. In the first trial involving 120 cows over 2 years the proportion among treated cows of quarters infected with Streptococcus agalactiae decreased from 21.8 to 1.6~ and with Staphylococcus aureus from 9.5 to 2.9~ whereas controls showed much smaller changes. The new infection rate was 1.03 infections per cow-year in treated cows and 1.50 in controls. Clinical mastitis was not reduced in treated cows due in part to an increase in coliform infections. Wisconsin Mastitis Test scores of quarter samples were significantly reduced in treated COWS.