Prevalence and Associated Risk Factors of Teat-End Hyperkeratosis in a Commercial Dairy Herd

Teat-end hyperkeratosis (THK) is a welfare concern in dairy cows, associated with pain, discomfort, and increased mastitis risk. Identifying risk factors associated with THK may support targeted preventive management. This cross-sectional observational study aimed to determine the prevalence of THK and identify factors associated with its occurrence. A total of 492 Holstein-Friesian cows were evaluated at the milking parlor of a dairy farm located in Évora, Portugal. All four teats per cow (n = 1968) were scored on a 4-point scale: no lesion (1), smooth ring (2), rough (3), and very rough skin (4). Parity, days in milk, teat length, teat-end shape, udder health, and milking procedures were assessed as potential factors associated with THK. A mixed-effects ordinal logistic regression model was used to evaluate the associations between THK and the selected factors. Overall THK prevalence was 54.4%, with a median score of 2 (range: 1–4; IQR: 1–2). Score distribution was 45.6% (score 1), 43.0% (score 2), 10.3% (score 3), and 1.1% (score 4). Round teat ends were associated with greater odds of severe THK compared with flat teat ends (OR = 6.4; p = 0.016). Longer milking duration (OR = 2.7 per 100 s; p = 0.002) and a history of mastitis (OR = 80.0; p < 0.001) were also positively associated with THK severity. These findings highlight opportunities to mitigate THK through optimized milking management and breeding strategies. Notably, factors such as mastitis and prolonged milking time are also associated with culling, potentially masking the true burden of THK on animal welfare.