How is the association of teat-end severe hyperkeratosis on udder health and dairy cow behavior?

Abstract

The teat-end hyperkeratosis is a pathology which causes pain and discomfort in dairy cows, increasing the risk of infection of the mammary gland. A total of 2,957 dairy cows from 43 farms in Portugal were examined to evaluate the teat-end, degree of hyperkeratosis and callosity on 11,828 teats. Factors related to milking management, characteristics of the individual and udder health status with the most severe level of hyperkeratosis were evaluated. The link between stepping and kicking during milking and the levels of hyperkeratosis was also investigated. Most animals observed (70%) showed signs of hyperkeratosis and 12% showed the teat-end more serious types, thick and extreme. The incidence of severe hyperkeratosis was highly variable between farms (1-35%) and front teats showed twice the risk compared to back teats (P <0.000). A trend towards higher levels of hyperkeratosis in cows with higher milk production was identified (P <0.094). Hyperkeratosis increased with parity (P <0.000) and for the period 61-180 days of lactation (P <0.000). Over-milking influenced hyperkeratosis levels (P <0.002). Higher levels of hyperkeratosis were observed on cows with a higher incidence of mastitis (P <0.004). More steps (P <0.025) but no kicks during milking were also associated with higher levels of hyperkeratosis. The results suggest that hyperkeratosis needs to be monitored in order to prevent and control this pathology, ensuring the udder health and welfare of dairy cows.