Effect of Different Surgical Incisions and Anesthesia Methods on Wound Healing in Recently Weaned Beef Calves

A total of 48 recently weaned Angus crossbred bull calves (292 ± 19.1 Kg of BW) were used to evaluate the effect of types of anesthesia and surgical cuts on scrotal wound healing after castration. Calves were randomly assigned to a 2×2 factorial design assessing surgical castration incisions (cut made with Newberry knife (K) vs. bottom cut made with scalpel (B)) and method of anesthesia injected 20 min before castration (local anesthesia injected in the spermatic cord, around the neck of the scrotum and testicles (L; Lidocaine HCl 2%) vs. epidural (E; Xylazine)) to yield KL, KE, BL, BE (12 calves/group). Wound healing was assessed in all calves over a 63 d period post-castration using maximum scrotal area temperature (MST, °C) assessed via infrared thermography, scrotal circumference (SC, cm), visual evaluation of swelling (SW, 5 point-scale being 0: no swelling, and 5: increased degree of swelling with presence of pus) and healing of the incision site (HI, 5-point scale: being 1: incision open without scabbing, and 5: incision completely healed). Data was collected 8h post-castration, on d 1, 2, 4, 7, 14, 17 and 21 post-castration, and weekly thereafter until the end of the study. Pain sensitivity was evaluated using a Von Frey anesthesiometer (g) following the same schedule. Data was analyzed using a mixed-effect model with incision, anesthesia, time and their interactions as fixed effects and pen within animal as a random effect. An incision × time interaction (P < 0.05) was observed for MST, HI, and SW. The MST for B was greater (P < 0.05) on d 35, 56 and 63 compared to K calves. In addition, B calves tended to have greater HI scores (P = 0.06) on d 21, 28 and 35 than K calves, although no differences were observed at the end of the assessment period. In addition, from d 35 to 63, B calves had greater (P = 0.01) SW than K calves. Finally, calves administered local anesthesia tended to have greater scores for HI (P = 0.06) and lower SC (P < 0.001) than calves administered epidural anesthesia. No differences in pain sensitivity were observed between types of surgical incisions or methods of anesthesia. In summary, calves castrated using a Newberry knife and anesthetized using a local anesthetic healed faster and presented less swelling consistent with improved healing.