Impact of hot-iron application time and tip size on wound characteristics and healing in dairy calves

Hot-iron disbudding is a routine practice in dairy farming, but variations in technique can significantly affect wound characteristics and healing. This study evaluated the effects of hot-iron tip size and application duration on disbudding wounds in calves using a split-plot design. Calves (days old) were randomly assigned to 10- or 20- second application times, while each horn received either a small or large tip- procedures were standardized under sedation and local anesthesia, with wound temperature, size, and depth monitored every three days after disbudding. Both tip size and application duration significantly affected wound outcomes. Wound size was greater with large tips (3.48 ± 0.31 cm²) than small tips (2.13 ± 0.20 cm²); and slightly greater with longer duration (2.94 ± 0.76 cm² vs. 2.66 ± 0.68 cm²). wound depth increased with large tips (2.43 ± 0.49 mm vs. 2.03 ± 0.31 mm) and longer application (2.49 ± 0.43 mm vs. 1.97 ± 0.29 mm). necrotic tissue detachment occurred earlier in small-tip and short-duration groups. These results indicate that both hot-iron tip size and application duration markedly influence disbudding wound dimensions, depth, and healing, emphasizing the need for precise procedural control to optimize welfare.