Hot-
iron branding is painful for cattle, but little is known about the duration of or effective methods to control this
pain. This work quantified
pain sensitivity and healing in branded and unbranded animals. In addition, the effects of a single injection of nonsteroidal anti-inflammatory
drug (
NSAID) were also considered; this has been suggested as practical method of mitigating
pain in the hours after the procedure. Calves (mean±SE, 126±2.2 d and 112±2.8 kg) were hot-
iron branded and allocated to 1 of 4 treatments: branded with or without
flunixin meglumine (intravenous; 1.1 mg/kg) and unbranded with or without this
NSAID (n=12/treatment).
Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in the center of the brand (or equivalent area in nonbranded treatments) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). These measures, along with
weight gain and surface temperature, were recorded 1, 2, 7, 14, 21, 28, 35, 42, 56, and 71 d after branding. Lying behavior was recorded with loggers from the day before to d 27 after branding. Brand
wounds were more painful than nonbranded tissue (P<0.001). These differences were most pronounced in the days immediately after branding (e.g., d 7; 113±36 g of force for Brand vs. 449±23 g force for No brand, mean±SE) but persisted until d 71 (380±37 g force for Brand vs. 453±23 g of force for No brand, mean±SE); only 67% of brands were fully regimented or healed by this time. The first fully healed brand was identified 8 wk after the procedure. Giving a single injection of
flunixin had no brand-specific effects on sensitivity, surface temperature, or healing but improved
weight gain in the days after branding in all treated groups (flunixin×brand×day, P<0.001).
Flunixin-treated animals also spent 0.7 h less time lying down on the day of branding but tended to spend more time lying on d 15 and 26 after the procedure. The magnitude of these differences is small, less than the day-to-day variation, and not brand specific. In summary, brand
wounds take at least 8 wk to heal. These
wounds remain painful for a least this long, and a single injection of
NSAID has no measurable effect in mitigating
pain associated with branding, even in days immediately after the procedure.