Prevalence of Sole ulcer in Dairy Cows Exposed to Heat Stress

The aim of this study was to investigate the seasonal thermal effect on the prevalence of the sole ulcer in dairy cows. The observations were performed on a Holstein-Friesian (HF) dairy farm in Eastern Slovakia. The clinical signs of heat stress were recognised in several animals during the afternoon milking on July 8, 2015. The claw examination done three months after the heat stress episode was compared with three examinations: twelve and two months prior to the heat stress and ten months afterward. The orthopaedic examinations were focused on the prevalence of the sole ulcer. Statistical analysis was performed by running a chi-squared test. The temperature-humidity index (THI) on July 8, 2015, was 88. We found 15.2 %, 18.6 %, 28.1 %, and 12.9 % cows with sole ulcer in the autumn 2014, spring 2015, autumn 2015, and spring of the following year, respectively (P < 0.05). In conclusion, the results of our observations showed that the heat stress in dairy cows can be associated with an increase in the prevalence of the sole ulcer.