Master of Science / Department of Clinical Sciences / Hans Coetzee / Dehorning is a painful husbandry procedure that is commonly performed in dairy calves. Parenteral meloxicam combined with local anesthesia mitigates the physiological and behavioral effects of dehorning in calves. The purpose of this study was to determine the influence of timing of oral meloxicam administration on physiological responses in calves after dehorning. Thirty Holstein bull calves 8- 10 weeks of age (28-70 kg) were randomly assigned to one of three treatment groups: placebo-treated control group (CONT) (n=10), calves receiving meloxicam administered orally (1 mg/kg) in powdered milk replacer 12 h prior to cautery dehorning (MEL-PRE) (n=10) and calves receiving meloxicam administered as an oral bolus (1 mg/kg) at the time of dehorning (MEL-POST) (n=10). Following cautery dehorning, blood samples were collected to measure cortisol, substance P (SP), haptoglobin, ex-vivo prostaglandin E2 (PgE2) production after lipopolysaccharide stimulation and meloxicam concentrations. Maximum ocular temperature (MOT) and mechanical nociceptive threshold (MNT) was also assessed. Data were analyzed using non-compartmental pharmacokinetic analysis and repeated measures ANOVA models. Mean peak meloxicam concentrations were 3.61 ± 0 .21 μg/mL and 3.27 ± 0.14 μg/mL with average elimination half-lives of 38.62 ± 5.87 h and 35.81 ± 6.26 h in the MEL-PRE and MEL-POST groups respectively. Serum cortisol concentrations were lower in meloxicam-treated calves compared with control calves at 4 h post-dehorning (P=0.0004). SP concentrations were significantly higher in control calves compared with meloxicam-treated calves at 120 h after dehorning (P=0.038). PgE2 concentrations were lower in meloxicam-treated calves compared with control calves (P=0.001). MNT was higher in control calves at 1 h after dehorning (P=0.02) but meloxicam-treated calves tended to have a higher MNT at 6 h after dehorning (P=0.07). There was no effect of timing of meloxicam administration on plasma cortisol concentrations (P= 0.69), SP concentrations (P=0.86), haptoglobin concentrations (P=0.86), MOT (P=0.90), or MNT (P=0.99). However, PgE2 concentrations in MEL-PRE calves were similar to CONT calves after 12h post-dehorning, while MEL-POST calves had lower PgE2 concentrations for 3 d post dehorning. These findings suggest that meloxicam reduced cortisol, SP and PgE2 after dehorning but only PgE2 production was significantly affected by the timing of meloxicam administration.

Master of Science / Department of Clinical Sciences / Daniel U. Thomson / Cross-bred horned steers and heifers (n = 40; BW = 311.8 ± 4.7 kgs.) were used to determine the effect of dehorning methods on pain, cattle behavior and wound healing. Cattle were blocked by weight and randomly assigned to 1 of 4 treatments: 1) control (CON); 2) banded using high tension elastic rubber (BAND); 3) mechanically removed (MECH); or 4) tipped (TIP). Vocalization and behavior were recorded during the dehorning process. Wound healing scores, attitude, gait and posture, appetite, and lying were recorded daily. Data were analyzed using the Wilcoxon Rank Sum Test of SAS (Cary, NC). Vocalization scores were highest for MECH, and the BAND cattle vocalized more than TIP and CON (P < 0.05). There were treatment effects for gait and posture (P = 0.03), appetite (P = 0.01) and lying scores (P < 0.01), BAND cattle had higher scores (P < 0.10) in these parameters compared to MECH, TIP and CON cattle. There was treatment by time interactions for attitude (P < 0.01), horn bud (P < 0.01) and bleeding (P < 0.01). BAND cattle had increased attitude scores in weeks 1, 3 and 4 (P < 0.10), increased hornbud scores in weeks 3 and 4 (P < 0.05) and increased bleeding scores in week 3 (P < 0.05). These data indicate that MECH is a painful procedure for cattle at the time of the procedure. Banding to remove horns from cattle is not recommended based on the data and observations from this study.

Master of Science / Department of Clinical Sciences / Johann F. Coetzee / Objective—To determine the pharmacokinetic parameters of xylazine, ketamine, and butorphanol administered IM and sodium salicylate administered PO and to compare their effect on biomarkers of pain and distress following sham (Period 1) and actual (Period 2) castration and dehorning. Animals—40 Holstein bull calves Procedures—Calves weighing 108 to 235 kg received the following treatments prior to sham castration and dehorning (Period 1) and castration and dehorning (Period 2) (n=10 calves/group): (i) 0.9% saline solution IM (PLACEBO) (ii) sodium salicylate (SAL) supplied free-choice in water to provide concentrations from 2.5 to 5 mg/mL beginning 24 hours prior to Period 1 to 48 hours after Period 2; (iii) 0.025 mg/kg butorphanol, 0.05 mg/kg xylazine, 0.1 mg/kg ketamine co-administered IM immediately prior to both periods (XKB); and (iv) a combination of treatments (ii) and (iii) (SAL + XKB). Plasma drug concentrations, average daily gain (ADG), chute exit speed, serum cortisol concentrations and electrodermal activity (EDA) were evaluated. Results—ADG (0-13d) was significantly greater in the SAL and SAL + XKB groups. Calves receiving XKB had significantly slower chute exit speed in both periods. Serum cortisol concentrations were significantly increased in all groups during Period 2 compared to Period 1. However, XKB attenuated serum cortisol response for the first hour after castration and dehorning while oral salicylate significantly reduced cortisol from 1-6 hours. XKB administration significantly decreased EDA scores in both periods. Conclusions and Clinical Relevance—Free-choice sodium salicylate decreases cortisol concentrations and reduced weight loss associated with castration and dehorning in calves.

Master of Science / Department of Animal Science and Industry / L.N. Edwards-Callaway / This thesis includes two studies that assessed pain responses to husbandry procedures in order develop mitigation tools. The objective of the first trial was to identify method-related differences in behavioral pain responses in calves of two ages (6 week and 6 months) subjected to castration: surgical cut (CP; n=18), surgical cut and emasculator (CC; n=20), rubber banding (BAND; n=18), or control manipulation of the scrotum (CONT; n=20). Behavior was evaluated pre- and post-castration to record foot stamps, tail flicks, kicks, elimination, in addition to standing and lying post-castration. For 6 week calves, the probability of kicking and eliminations was greater for surgical castrates and all castrated animals, respectively. The probability of kicking was greatest for all 6 month castrates while BAND and CONT had greater probability of elimination. Both age groups increased standing post-castration. Lying decreased in 6 week calves but was unchanged for 6 month calves. Six week calves displayed more tail flicks and tended to display less foot stamps than 6 month calves. Six week calves showed a decrease in tail flicks and foot stamps in response to castration while 6 month calves showed an increase in both behaviors. CP and CC, but not BAND, resulted in less tail flicks than CONT post castration. The second trial compared the effects of preemptive analgesics administered to calves subjected to dehorning with local anesthesia. Six month Holstein steers were randomly assigned to receive one of the following treatments (n= 8/group): meloxicam (1 mg/kg PO), gabapentin (15mg/kg PO), meloxicam (1 mg/kg) and gabapentin (15 mg/kg) PO, flunixin (2.2 mg/kg IV), or a placebo. Drug, cortisol, ex-vivo prostaglandin, haptoglobin, and substance P concentrations, ocular thermography, algometry, and average daily gain were evaluated. Analgesic-treated calves had lower plasma SP concentrations and improved ADG compared with controls. Flunixin calves had reduced cortisol and ex-vivo prostaglandin concentrations for 24h compared to controls. Meloxicam treated calves showed an increase in MNT at two horn bud sites compared with the other treatments. Overall, the results provide validation of responses to noxious stimuli that can be used to develop pain alleviation for livestock.

Les pratiques d’élevage courantes effectuées en production vache-veau sont nécessaires, mais certaines d’entre elles peuvent causer de la douleur ou du stress aux animaux. Les données disponibles sur la façon dont elles sont réalisées ainsi que sur les stratégies en place qui réduisent l'impact négatif sur le bien-être animal dans les élevages vache-veau du Québec sont rares. Les objectifs de cette étude étaient donc 1) de décrire la façon dont les producteurs vache-veau réalisent les pratiques d'élevage courantes associées à la douleur et au stress (gestion du vêlage, castration, écornage, identification des animaux, sevrage et euthanasie); 2) d'évaluer l'utilisation de stratégies alternatives et de méthodes de gestion de la douleur ainsi que d’identifier les facteurs associés avec leur utilisation; et 3) de déterminer si ces pratiques sont en conformité avec les recommandations et les exigences décrites dans les normes canadiennes. Un questionnaire bilingue en ligne et sur papier administré en 2019 évaluant les pratiques des entreprises réalisées en 2018 a été rempli par 156 producteurs vache-veau de différentes régions du Québec. Dans l'ensemble, les entreprises avaient une médiane de 36,5 vaches adultes. Après un vêlage difficile assisté, 44,4% des producteurs ont déclaré avoir utilisé une méthode de gestion de la douleur pour au moins une vache ou un veau. La castration à l’élastique était la méthode de castration la plus commune (97,4%). La principale méthode d'écornage utilisée par les répondants était la pâte caustique (43,4%). Au total, 39,7% et 16,4% des producteurs ont administré un médicament pour la gestion de la douleur à au moins un veau lors de l'écornage et de la castration, respectivement. Aucun répondant n'a rapporté avoir marqué au fer des bovins. Le sevrage par séparation complète était la méthode de sevrage la plus répandue (54,2%). La mort naturelle due à une maladie chronique ou à la vieillesse était le type de décès à la ferme le plus courant chez les vaches adultes (40,9%). Environ un tiers des répondants (28,8%) a euthanasié au moins un animal en 2018. L’arme à feu était la méthode d'euthanasie la plus utilisée (63,6%). Les pratiques mises en œuvre étaient pour la plupart conformes aux normes de l’industrie canadienne du bœuf. L'utilisation de méthodes de gestion de la douleur ainsi que la prise de décision d'euthanasier en temps opportun représentent les principales lacunes à combler pour améliorer le bien-être des animaux dans les entreprises vache-veau du Québec. / Common husbandry practices that are carried out in cow-calf production are necessary, but some of these practices can cause pain or stress to animals. Data availability on how they are performed as well as the strategies that reduce the negative impact on animal welfare implemented in Quebec cow-calf operations are sparse. The objectives of this study were therefore 1) to describe how cow-calf producers perform common husbandry practices normally associated with pain and stress (calving management, castration, dehorning, animal identification, weaning, and euthanasia); 2) to assess the use of alternative strategies and pain mitigation practices as well as factors associated with their use; and 3) to determine if these practices are in compliance with the recommendations and requirements described by the Canadian guidelines. An online and paper-based bilingual questionnaire administered in 2019 evaluating on-farm practices carried out in 2018 was completed by 156 Quebec cow-calf producers from different regions. Overall, operations had a median of 36.5 adult cows. After an assisted difficult calving, 44.4% of producers reported having given pain mitigation at least to a cow or a calf. Band castration was the most used castration method (97.4%). More than half of respondents (62.5%) reported having > 75% of polled calves. The main dehorning method used by respondents was caustic paste (43.4%). A total of 39.7% and 16.4% of producers administered a pain mitigation drug to at least one of their calves undergoing dehorning or castration, respectively. No respondent reported the use of iron branding for cattle. Traditional abrupt weaning was the most reported weaning method (54.2%). Natural death from chronic disease or old age was the most common type of on-farm death in adult cows (40.9%). Less than a third of respondents euthanized at least one animal (28.8%) in 2018. The gunshot was the most reported euthanasia method (63.6%). As hypothesized, practices carried out were mostly in compliance with the Canadian beef industry guidelines. The use of pain mitigation practices and stress-reducing methods as well as timely euthanasia decisions represent the main shortcomings that should be addressed to improve the welfare of animals in Quebec cow-calf operations.