Measuring and managing pain and stress associated with castration in cull beef bulls
Date
2012
Authors
Repenning, Paul English, author
Ahola, Jason, advisor
Callan, Robert, committee member
Whittier, Jack, committee member
Engle, Terry, committee member
Fox, J. Trent, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
The objectives of this research were to evaluate the effects of: 1) castration, 2) castration method (band vs. surgical) and 3) use of analgesia on measures of behavior, feedlot performance, and physiological responses in cull bulls. In the first study, Angus, Hereford, and Angus crossbred bulls (n = 20; initial BW = 384 ± 59.3 kg; 336 ± 20.1 d old) were housed in feedlot pens equipped with the ability to measure individual daily feed intake. A balanced randomized block design using a 2 × 2 factorial arrangement of treatments was utilized. Factors included: 1) castration method (band vs. surgical), and 2) analgesia presence. A multimodal analgesia protocol (MMA) was used and consisted of subcutaneous ketamine-stun containing butorphanol (0.01 mg/kg), xylazine (0.02 mg/kg), ketamine (0.04 mg/kg), and a local 2% lidocaine hydrochloride anesthetic block of the spermatic cords (10 mL per cord) and scrotum (10 mL) on d 0. Flunixin meglumine (1.2 mg/kg) was also administered intravenously (iv) on d 0, 1, 2 and 3 to MMA cattle. Cattle were stratified to treatments based on breed, BW, age and a temperament score. Treatments included: 1) band castration without analgesia (BAND), 2) band castration with analgesia (BAND-MMA), 3) surgical castration without analgesia (SURG), and 4) surgical castration with analgesia (SURG-MMA). All castrations were performed on d 0. Chute exit velocity (EV) and time in chute (TIC) were collected on d -9, 0, 1, 2 and 13. Willingness-to-enter-chute (WTE) score, rectal temperature (TEMP), heart rate (HR), and respiration (RESP) were collected on d 0, 1, 2, 3 and 13. Cattle were weighed on d -9 and 13 while feeding behaviors were collected continuously for 57 d pre-castration and 28 d post-castration. There was a tendency (P < 0.09) for ADG to be greater in cattle receiving analgesia. Both SURG treatments exhibited greater TEMP on d 1 (P < 0.001) and 2 (P < 0.05) compared to both BAND treatments. Mean DMI post-castration was greater (P = 0.02) in MMA treatments compared with non-medicated treatments. Meal duration was greater (P < 0.05) in both BAND treatments than in surgical castrates in wk 1 post-castration. Results suggest that pain mitigation reduces the impact of castration on ADG and DMI. The second study was comprised of 2 experiments. In Exp. 1 Angus and Charolais-crossbred bull calves (n = 127; 309.8 ± 59.04 kg) and in Exp. 2 Hereford, Angus, and Hereford × Angus crossbred bulls (n = 30, 300.8 ± 4.96 kg), were stratified by BW and randomly assigned to 1 of 3 treatments: 1) band castration (BAND), 2) band castration with oral administration of meloxicam (BAND-MEL), and 3) sham castration (SHAM). The BAND and SHAM procedures were completed on d 0. The SHAM treatment consisted of all animal manipulations associated with band castration without band application. Meloxicam was administered on d -1, 0, and 1 (1.0 mg/kg, 0.5 mg/kg and 0.5 mg/kg, respectively) via an oral bolus. Body weight and a subjective chute score (CS) were collected on d -1, 0, 1, 7, 14, 21 and 28 (Exp. 1 only). In Exp. 1, jugular blood samples were collected immediately before castration and 24 hr post-castration for Substance P (SP) analysis. In both experiments, video documentation on d 0 was used to determine range of vertical head motion (DIST) on a subset of animals during treatment administration. In both experiments, ADG was similar (P > 0.10) between BAND and BAND-MEL, but ADG in SHAM cattle was greater (P < 0.001) and tended (P = 0.07) to be greater in castrates in Exp. 1 and 2, respectively. In Exp. 1, CS did not differ (P > 0.10) between BAND and BAND-MEL on any d, but castrates exhibited greater CS on d 1 and 28 than SHAM cattle. In Exp. 2, CS was not affected (P > 0.10) by castration or the presence of meloxicam. In Exp. 1, DIST did not differ (P > 0.10) between BAND and BAND-MEL, but when pooled, castrates exhibited greater (P = 0.04) DIST than SHAM. In Exp. 1, plasma SP concentrations did not differ (P > 0.10) across treatments. Results indicate no impact of meloxicam administration on performance or behavioral and physiological responses to band castration. However, there was an impact of castration on ADG and CS.
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Subject
behavior
welfare
pain mitigation
castration
meloxicam
beef bulls