Relationship of Teat-end Hyperkeratosis to Incidence of Clinical Mastitis and Composite Milk Somatic Cell Count in a Large Holstein Dairy Herd with an Environmental Mastitis Problem

Abstract

Several studies have demonstrated a positive association between teat-end hyperkeratosis (TEHK) and subclinical or clinical mastitis. Some studies found no positive correlation between them. To the knowledge of the authors, there is only one longitudinal study which demonstrated a negative association between teat-end callosity thickness and clinical Escherichia coli mastitis (Neijenhuis et al, 2001). The objective of this study was to determine whether TEHK is associated with an increased risk of clinical or subclinical mastitis in a large Holstein dairy herd in Tehran province of Iran, in which the monthly incidence rate of clinical mastitis was 9% prior to the beginning of the study.