The Importance of Teat Canal Closure and Other Risk Factors On Dry Period Intramammary Infections

Abstract

For the first few weeks after drying-off, and then again immediately prior to calving, cows are at increased risk for developing new intramammary infections (IMI). Research supports that this susceptibility is related to variations in the teat streak canal as well as inherent biochemical and cellular changes occurring in the udder. The time in which the udder is most resistant to dry-period infections is when it has become fully involuted, and when each quarter has formed a natural teat streak canal keratin plug which acts as a physical barrier to close the teat canal. Recent research has been published demonstrating that not all quarters become closed by the teat canal keratin plug, and that dry period clinical mastitis is more likely to occur in quarters that do not close. In addition, products administered at drying-off which act as an inert physical barrier to ensure teat canal closure during the dry period ( OrbeSeal®) have been shown to be efficacious in preventing new IMI. Hence, risk factors associated with teat canal closure would be important to identify.