Inter-Quarter Variation in the Prevalence and Severity of Teat-End Hyperkeratosis in Dairy Cows

Teat-end hyperkeratosis (THK) is a common welfare issue in dairy cows, causing pain and discomfort. It is closely linked to both the udder morphology and the milking system. This study aimed to assess whether the prevalence of THK differs between the fore- and hindquarters of dairy cows. A total of 492 cows (n = 1,968 teats) from a commercial dairy farm in Évora, Portugal, were evaluated for THK. The presence and severity of THK were scored on a scale of 1 (no lesion) to 4 (very rough skin). Cows were classified into one of the following categories: forequarters affected, hindquarters affected, both quarters affected, or all teats affected. Data were analysed using the Kruskal–Wallis test, followed by Dunn’s post hoc test in R. Of the 288 cows (58.5%) with THK, 22 had lesions only in the forequarters, 7 in the hindquarters, 5 in both quarters, and 254 in all teats. Notably, the severity of THK was lower in cows with lesions on all teats (2.2±0.03) compared to those with lesions confined to the forequarters (3.14±0.09), hindquarters (3.0±0.16), or both quarters (3.0±0.19). This study found a high prevalence of THK affecting all teats, regardless of the quarter, suggesting a significant influence from the milking system. However, the severity of THK was greater when only one to three teats were affected, potentially reflecting variations in the morphology of individual teats within the same udder.