Effects of a topically applied anaesthetic on the behaviour, pain sensitivity and weight gain of dairy calves following thermocautery disbudding with a local anaesthetic

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New Zealand Veterinary Journal ISSN: 0048-0169 (Print) 1176-0710 (Online) Journal homepage: https://www.tandfonline.com/loi/tnzv20 Effects of a topically applied anaesthetic on the behaviour, pain sensitivity and weight gain of dairy calves following thermocautery disbudding with a local anaesthetic EL Cuttance, WA Mason, DA Yang, RA Laven, J McDermott & K Inglis To cite this article: EL Cuttance, WA Mason, DA Yang, RA Laven, J McDermott & K Inglis (2019) Effects of a topically applied anaesthetic on the behaviour, pain sensitivity and weight gain of dairy calves following thermocautery disbudding with a local anaesthetic, New Zealand Veterinary Journal, 67:6, 295-305, DOI: 10.1080/00480169.2019.1640651 To link to this article: https://doi.org/10.1080/00480169.2019.1640651 © 2019 The Author(s). Published by Informa View supplementary material UK Limited, trading as Taylor & Francis Group Accepted author version posted online: 04 Submit your article to this journal Jul 2019. Published online: 07 Aug 2019. Article views: 396 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tnzv20 NEW ZEALAND VETERINARY JOURNAL 2019, VOL. 67, NO. 6, 295–305 https://doi.org/10.1080/00480169.2019.1640651 SCIENTIFIC ARTICLE Effects of a topically applied anaesthetic on the behaviour, pain sensitivity and weight gain of dairy calves following thermocautery disbudding with a local anaesthetic a EL Cuttance , WA Masona, DA Yang b , RA Laven b , J McDermotta and K Inglisc a VetEnt Research, Te Awamutu, New Zealand; bSchool of Veterinary Science, Massey University, Palmerston, New Zealand; cBayer New Zealand Ltd, Auckland, New Zealand ABSTRACT ARTICLE HISTORY Aims: To compare

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eterinary Science, Massey University, Palmerston, New Zealand; cBayer New Zealand Ltd, Auckland, New Zealand ABSTRACT ARTICLE HISTORY Aims: To compare the effect of a topically applied anaesthetic to no pain relief or meloxicam on Received 16 October 2018 the behavioural responses, pain sensitivity and weight gain of calves following disbudding with Accepted 6 June 2019 or without sedation. Published online 4 July 2019 Methods: A total of 364, 2–6 week-old calves from three commercial farms were systematically KEYWORDS allocated to one of six treatment groups. All calves received a cornual nerve block prior to Disbudding; dehorning; disbudding, with half restrained in a crate and half sedated with xylazine. Within these topical anaesthetic; pain groups one third received no further treatment (control), one third were treated with relief; calves; behaviour; meloxicam >10 minutes prior to disbudding and one third received a topical anaesthetic weight gain applied to the horn bud wounds following disbudding. The frequency of ear flicks, head shakes, head scratches and pain sensitivity of the wound were recorded on up to eight occasions over 24 hours after disbudding. Calves were weighed before, and 7 and 28 days after, disbudding to determine average daily weight gain (ADG). Results: Compared to calves in the crate-control group, all other groups had reduced ear flicks at all times following disbudding (p < 0.01). Treatment with meloxicam and topical anaesthesia in addition to sedation reduced head scratches compared to calves in the crate-control group (p ≤ 0.013). At 22 hours after disbudding head shakes were reduced in sedated calves treated with topical anaesthetic compared to calves in the crate-control group (p < 0.001). Pain sensitivity was lower in all

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educed in sedated calves treated with topical anaesthetic compared to calves in the crate-control group (p < 0.001). Pain sensitivity was lower in all sedated calves than unsedated calves (p < 0.001). The ADG between Days 0–7 was 0.14 (95% CI = 0.015–0.274) kg/day greater in sedated calves treated with meloxicam than calves in the crate-control group (p = 0.03), and the ADG between Days 0–28 tended to be 0.06 (95% CI=−0.01–0.13) kg/day greater in sedated calves treated with topical anaesthetic than calves in the crate-control group (p = 0.09). Conclusion and clinical relevance: Sedation of calves for disbudding reduced the pain experienced in the following 24 hours. There was a benefit to providing calves with topical anaesthetic following disbudding on behavioural responses and pain sensitivity, which was similar to that of treating calves with meloxicam. Abbreviations: ADG: Average daily gain; IRR: Incidence rate ratio; NSAID: Non-steroidal anti- inflammatory drug Introduction (within 2–3 hours), behaviours such as ear flicking In New Zealand large numbers of calves are disbudded and head shaking increase, as do concentrations of cor- every year, usually within the first 2 months of life. tisol, with these pain-associated changes lasting for at While currently, disbudding is permitted without local least 24 hours after disbudding (Faulkner and Weary anaesthesia, new regulations due to be introduced on 2000; Sutherland et al. 2002). 1 October 2019 require that the disbudding of all The pain associated with disbudding can be calves in New Zealand must be undertaken using an reduced by giving a systemic non-steroidal anti-inflam- appropriately placed and effective local anaesthetic matory drug (NSAID; Stafford et al. 2003; Heinrich et al. (Anonymous

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emic non-steroidal anti-inflam- appropriately placed and effective local anaesthetic matory drug (NSAID; Stafford et al. 2003; Heinrich et al. (Anonymous 2018). However, while disbudding with 2010; Bates et al. 2015) and sedation (McMeekan et al. local anaesthesia is effective for reducing physiological 1999; Bates et al. 2016), although neither of these are and behavioural responses during disbudding (Petrie effective at eliminating the physiological and behav- et al. 1996), once the local anaesthesia wears off ioural responses during disbudding. Furthermore, CONTACT E. L. Cuttance emma.cuttance@vetent.co.nz Supplemental data for this article can be accessed at https://doi.org/10.1080/00480169.2019.1640651. © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by- nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. 296 E. CUTTANCE ET AL. whilst many calves in New Zealand are disbudded the studies used amputation or scoop dehorning of 2– under sedation (N. Harding1 pers. comm.), the use of 8 month-old calves, rather than hot iron disbudding of analgesics in calves disbudded, either under sedation 2–3 week-old calves which is much more common on or whilst unsedated and restrained in a crate, is New Zealand dairy farms. In addition no studies have limited due to the additional cost and perceived lack evaluated the use of topical anaesthetic in calves of economic benefit. sedated with xylazine prior to disbudding,

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e additional cost and perceived lack evaluated the use of topical anaesthetic in calves of economic benefit. sedated with xylazine prior to disbudding, which is The welfare of dairy calves is coming under greater the standard practice for veterinarian-led disbudding scrutiny as consumers increasingly consider animal on dairy farms in New Zealand. welfare when purchasing food (Verbeke 2009). There- The aims of this study were to investigate the effect fore there is a need to reduce the impact of disbudding of a topically applied local anaesthetic following dis- on calf welfare beyond the use of just local anaesthesia, budding, using either a crate for restraint or sedation, and for a practical and cost effective way of delivering in comparison to either the NSAID meloxicam adminis- additional pain relief during and after disbudding. The tered at disbudding or no post-disbudding pain relief, only registered topical anaesthetic drug for large on the behavioural responses, pain sensitivity and animal use is an antiseptic gel spray containing ligno- weight gain of calves. caine, bupivacaine and adrenaline (Tri-Solfen; Bayer Australia Ltd.), which was originally registered in Aus- tralia for use in lambs to provide pain relief following Materials and methods mulesing and tail docking. Since 2016 Australian regis- Calf selection and allocation to groups tration has included provision of pain relief during and following surgical castration of lambs and calves, and All animal procedures were approved by the Ruakura from June 2018 it has been registered for use after Animal Ethics Committee (AgResearch, Hamilton, NZ). calf disbudding or dehorning. This study was conducted between 26 March and 4 This product was evaluated in 30 Holstein-Friesian, 2 May 2018 on three

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calf disbudding or dehorning. This study was conducted between 26 March and 4 This product was evaluated in 30 Holstein-Friesian, 2 May 2018 on three conveniently located, autumn- month old calves, when applied after scoop dehorning, calving, commercial farms in the Waikato region of compared to no pain relief, and was found to reduce or the North Island of New Zealand. remove responses to mechanical stimulation from 4– Two weeks prior to the study start date, an elec- 24 hours after application (Espinoza et al. 2013). In tronic list of the identification, date of birth and another study the topical anaesthetic, applied after breed of all calves born between 1st February 2018 scoop dehorning, was compared with a cornual nerve up until the 14 days prior to the study start date block applied prior to dehorning, and found no differ- were provided by the farmer. All calves between 2–6 ence in pain sensitivity after dehorning (McCarthy et al. weeks of age on the study start date (Day 0) were eli- 2016). However this study had errors in its statistical gible to be examined for selection in the trial. analysis and was grossly underpowered to detect any All eligible calves were examined on Day −1 for differences. Another study, using 6–8 month-old Bos signs of disease (e.g. navel ill, scours, pneumonia) by indicus calves undergoing concurrent castration and a veterinarian and checked for the presence of horn amputation dehorning, investigated the use of the buds. Calves with disease or polled were not eligible topical anaesthetic and buccal meloxicam, without for the trial. Every healthy, eligible calf was weighed any local anaesthesia, on post-operative weight gain on electronic weigh scales. On Farms 1 and 2, where and behaviour. Very little consistent effect of

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ny local anaesthesia, on post-operative weight gain on electronic weigh scales. On Farms 1 and 2, where and behaviour. Very little consistent effect of treatment there were smaller numbers of calves, the age of the was found on most of the measured behaviours or calves ranged from 2–6 weeks so calves were ordered weight gain over the first 6 days after castration and by weight and systematically allocated into one of six dehorning (Van der Saag et al. 2018b). In a similar groups. On Farm 3 there were 60 calves per visit, study using 6–8 month-old Hereford calves under- which were first categorised according to age and going amputation dehorning alone, there was no then within age category they were ordered by clear effect of topical anaesthetic or buccal meloxicam weight and systematically allocated into one of six on behaviour, maximum wound temperature or wound groups. The mean weight and age of the six groups morphology after dehorning (Van der Saag et al. were determined to ensure there were no major discre- 2018a). These studies have limited relevance outside pancies between groups. Australia and similar extensive range farming systems, A description of the treatment groups is shown in as they did not investigate the use of topical anaes- Table 1. As there were multiple outcomes measured thetic alongside local anaesthesia. Topical anaesthetics for the trial, calves were allocated by cohort for either cannot be used to control pain during disbudding, as behavioural observation or pain sensitivity testing would be legally required in many jurisdictions, includ- (Figure 1). The first cohort of eligible calves on a farm ing New Zealand after 1 October 2019. Furthermore, all were all allocated for behavioural observation. The 1 N. Harding, DairyNZ, Hamiton,

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s on a farm ing New Zealand after 1 October 2019. Furthermore, all were all allocated for behavioural observation. The 1 N. Harding, DairyNZ, Hamiton, New Zealand. NEW ZEALAND VETERINARY JOURNAL 297 Table 1. Description of the six different treatment groups used within the same calf house on Day −1. Calves assigned to investigate the effect of a topical anaesthetic (TA)a on the to pain sensitivity testing were separated into two behaviour, pain sensitivity and weight gain of dairy calves groups; one for sedation and one for crate disbudding. following cautery disbudding. Group Treatment 1 Crate disbudding, local 5 mL lignocaineb applied to each Experimental procedure anaesthetic and TA placebo horn bud, 4 mL TA placebo after disbudding All calves were fed the evening before Day 0 but not on 2 Crate disbudding, local 5 mL lignocaineb applied to each anaesthetic and meloxicam horn bud, 1.4 mL S/C the morning of Day 0. Two teams of technicians carried and TA placebo meloxicamc, 4 mL TA placebo out the disbudding following administration of local after disbudding 3 Crate disbudding, local 5 mL lignocaineb applied to each anaesthetic nerve blocks; one team of two disbudded anaesthetic and TA horn bud, 4 mL TA after calves while they were fully conscious, restrained in a disbudding crate and the other team of two disbudded following 4 Sedation disbudding, local 0.8 mL I/M xylazined, 5 mL anaesthetic and TA placebo lignocaineb applied to each sedation. The two teams worked simultaneously on horn bud, 4 mL TA placebo the groups of calves. The same person in the group after disbudding 5 Sedation disbudding, local 0.8 mL I/M xylazined, 5 mL of two administered all the nerve blocks and the anaesthetic and meloxicam lignocaineb applied to each other team member did all the

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M xylazined, 5 mL of two administered all the nerve blocks and the anaesthetic and meloxicam lignocaineb applied to each other team member did all the disbudding. and TA placebo horn bud, 1.4 mL S/C meloxicamc, 4 mL TA placebo For calves that were sedated, they were injected after disbudding with 3–4 mg (0.15–0.2 mL)/10 kg of 20 mg/mL xylazine 6 Sedation disbudding, local 0.8 mL I/M xylazined, 5 mL anaesthetic and TA lignocaineb applied to each (Xylazine 2% Injection; Phoenix Pharm Distributors, horn bud, 4 mL TA after Auckland, NZ) I/M in the neck. For the majority of disbudding calves, this was a dose of 0.8 mL (16 mg), but varied a Tri-Solfen (Bayer New Zealand Ltd, Auckland, NZ). b 20 mg/mL lignocaine (Bomacaine, Bayer New Zealand). from 0.6–1.2 mL (12–24 mg), depending on the c 20 mg/mL meloxicam (Metacam20; Boehringer Ingelheim NZ Ltd, Auck- weight of the calf. Animals were marked once injected land, NZ). to ensure the same animal was not injected twice. d 20 mg/mL xylazine (Xylazine 2% Injection; Phoenix Pharm Distributors, Auckland, NZ). In all calves both horns were desensitised using a cornual nerve block at least 10 minutes prior to disbud- second cohort of calves that were disbudded either ding, by injecting 5 mL (100 mg) of 20 mg/mL ligno- days or weeks later, depending on the farm and age caine (Bomacaine; Bayer New Zealand, Auckland, NZ) of the calves, were all allocated to pain sensitivity at depth of approximately 1 cm under the temporal testing. There were two cohorts per farm and behav- ridge around each cornual nerve. ioural observations and pain sensitivity measurements Calves that were allocated to receive meloxicam were were separated by between 2 days and 3 weeks. injected with 50 mg/100 kg (1.4 mL) of 20 mg/mL melox- Calves assigned to

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ated to receive meloxicam were were separated by between 2 days and 3 weeks. injected with 50 mg/100 kg (1.4 mL) of 20 mg/mL melox- Calves assigned to have behavioural observations icam (Metacam20; Boehringer Ingelheim NZ Ltd, Auck- recorded had their number spray marked along their land, NZ) S/C in the neck following the cornual nerve sides and their backs, were separated into their desig- block and at least 10 minutes prior to disbudding. nated groups and were placed in six separate pens In all calves the horn bud was prepared first by shaving the hair around the site using electric clippers. Disbudding was performed by thermocautery using a gas heated clean instrument with a 18 mm diameter head (Express LPG or Farm Hand disbudder, Shoof Hamilton, NZ). The horn bud was removed completely during the procedure. If calves showed an indication of pain after disbudding started, disbudding was stopped and the cornual nerve block was repeated. Following disbudding the wound at each horn bud was treated with either 2 mL of topical anaesthetic sol- ution (Tri-Solfen (Bayer New Zealand Ltd), containing 40.6 g/L lignocaine hydrochloride, 4.2 g/L bupivacaine hydrochloride, 24.8 mg/L adrenaline (as acid tartrate) and 5.0 g/L cetrimide) or 2 mL of a placebo. The placebo was identical to the topical anaesthetic but did Figure 1. Diagrammatic representation showing the allocation not include any lignocaine, bupivacaine, adrenaline or within farms of calves to be disbudded in a crate or sedated, cetrimide. The solutions were delivered using a hand and to receive no further treatment (C), or receive a topical held applicator (V-Grip 6 mL applicator; Genesis Industries, anaesthetic (TA) or meloxicam (M). The first cohort was observed after disbudding for behavioural measurements,

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ip 6 mL applicator; Genesis Industries, anaesthetic (TA) or meloxicam (M). The first cohort was observed after disbudding for behavioural measurements, Mudgee, NSW, Australia). In some cases when it ran off the and 3–21 days later the second cohort had pain sensitivity wound site excess was caught with a towel on the side of measurements recorded after disbudding. the head to avoid product going into the eyes of calves. 298 E. CUTTANCE ET AL. After disbudding, all calves that were allocated to Table 2. Definitions of behaviours that were observed in dairy behavioural observations remained in their separate calves following cautery disbudding. pens until 24 hours following disbudding. All calves Behaviour Description that were allocated to the pain sensitivity testing were Ear flicking Calf rapidly moves one or both ears to the front and back independent of a head shake. Each time movement in two joined pens (one for sedated calves and one for constitutes as an ear flick. crate calves) for 24 hours. After 24 hours all calves Head shaking Calf rapidly shakes head from one side to the other. Recorded as one behaviour when the head moved were joined together. They were provided with clean slowly or was in a resting position. water, a new batch of calf meal and a milk feed. The Head Calf lifts hind leg to scratch top of head with foot or rubs scratching head against sides of the pen. remainder of the feeding was as per usual farm practice. At the completion of the observations, the data were Behavioural observation collated so all the observations of a calf from a farm at a Calves in the pens were video recorded, starting at set time could be compared to determine discrepancies 12:00 hours on Day−1 and continuing until 09:00 hours between observers. A supervisor

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tarting at set time could be compared to determine discrepancies 12:00 hours on Day−1 and continuing until 09:00 hours between observers. A supervisor then viewed all of the on Day 1. Four Arlo Pro 2 (Arlo Technologies Inc., San videos with discrepancies in recorded observations of Jose, CA, USA) video cameras with night vision were >3 between observers. In cases of clear error (e.g. 2–3 mounted near the roof of the calf pens. They were posi- observers reported 5–7 head shakes and one observer tioned such that all six treatment pens were observable reported 18), the supervisor made a judgment call on in at least one of the camera recordings, and were whether to use the median result, remove a single tested to ensure that they were able to capture all areas observer or remove multiple observers for that obser- of the calf pens. vation, so that there was one measurement for each Approximately 7–10 minutes of video were down- calf at each time. loaded at the start of each of hour, at 0, 1, 3, 5, 7, 9, Activity monitoring using HeyrexVet (Heyrex, Well- 12 and 22 hours following disbudding, onto Arlo Tech- ington, NZ) wearable monitors was also undertaken. nologies cloud system, which were then subsequently As this activity monitor has not been validated in copied onto USB drives for observations. Therefore calves the methods and results are described in Sup- for each individual calf a total of ∼65–80 minutes of plementary Information 1.2 footage was recorded over 24 hours. A total of 22 trained observers watched the video Pain sensitivity testing footage for ear flicking, head shaking and head scratch- ing by individual calves, as described in Table 2. The It was originally intended that pain sensitivity testing observers were supervised by two of the authors

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dividual calves, as described in Table 2. The It was originally intended that pain sensitivity testing observers were supervised by two of the authors (ELC would be conducted at 1, 2, 3, 4, 6, 8, 10, 12 and and WAM) and worked in pairs to watch the footage 24 hours after disbudding, using a pressure algometer together on a 50 cm computer screen. The observers (FPX 50, Wagner Instruments, Greenwich, CT, USA) were provided with a selection of specific videos and applied at eight locations around the horn bud, as were instructed on what pen they were observing, shown in Figure 2. This required placing the algometer the calf identification numbers in that pen and the rubber tip over the cautery wound at the edge of time period of observation. They each watched a normal tissue. However on the first farm where pain single calf in the pen, then another until all calves sensitivity testing was carried out the veterinarian were observed once for that time. They were encour- undertaking the testing immediately expressed aged to re-watch the footage and ask for help from concern about the level of pain that the calves were supervisors for certainty. They recorded the calf experiencing. Therefore the placement of the alg- number, the description of the calf, and the count of ometer was limited to positions 1 and 2 on each horn the behaviours shown throughout the time periods. bud (Figure 2) and testing was carried out at 0–1, 2– After a pair had finished watching all the calves once, 5, 6–11, 12 and 24 hours after disbudding. another pair of observers followed the same procedure Testing was conducted with two people restraining with the same videos. Therefore, each calf at each time the calf. The veterinarian carrying out the testing was watched by between 2–4 separate

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aining with the same videos. Therefore, each calf at each time the calf. The veterinarian carrying out the testing was watched by between 2–4 separate trained obser- initially placed a hand lightly on the poll of the calf vers who were unaware of any previous observation until the calf was habituated to being touched and results. The calves that were positioned in the pens stood still. The hand was then removed and replaced furthest away from the cameras were observed more with the algometer rubber tip at the two positions frequently. The observers had no knowledge of the around each horn bud wound. The force (N) that was trial other than the behaviours that they had to able to be applied against the wound before the calf record and were therefore completely blinded. moved away from the stimulus was recorded. 2 https://doi.org/10.1080/00480169.2019.1640651. NEW ZEALAND VETERINARY JOURNAL 299 likelihood of losing animals to follow up after enrolment. For the behavioural observations approximately 90 animals, 16 in each group, were required to detect an approximate 40% difference in the incidence of head shakes between groups. Approximately 132 animals were required for the pain sensitivity component of the trial, to detect a difference between groups of 7 N with a SD of 10 N, at any single time. Behavioural observation Data for the total number of ear flicks, head shakes and head scratches recorded at 0, 1, 3, 5, 7, 9, 12 and 22 hours after disbudding were analysed separately. The data for ear flicks and head scratches were mod- Figure 2. Diagram showing the position of pressure algometer placement for measurement of pain sensitivity in calves follow- elled using two separate mixed effects negative bino- ing disbudding. The black ovals indicate the position of

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nt of pain sensitivity in calves follow- elled using two separate mixed effects negative bino- ing disbudding. The black ovals indicate the position of the mial regression models, where calf was treated as horn bud wound and the numbers indicate the location for pla- random effects, and the natural logarithm of length cement of the pressure algometer. of video recorded at each time period was added as an offset term. For head shakes, a mixed effects Poisson regression model with a robust standard Half of the calves were tested on the right horn first, error was adopted, which also included calf as a followed by the left horn, with the remainder tested in random effect and the same offset term. Initial explana- the opposite order. All calves returned to typical farm tory variables included in the multivariable models management (in one group) following the completion were farm, treatment group and time, and the inter- of the trial at 24 hours. All animal health events were action between treatment group and time. This inter- recorded and any animals that were suffering illnesses action term was included as it was possible that the were removed from the trial. Any calves that expressed treatments had a different duration of action. Starting an unusually high aversion to pain sensitivity testing with a full model that included the interaction term, (struggling, vocalisation) were removed from further fixed effects were dropped from the model if Akaike assessments on welfare grounds. information criteria from the simpler model was In addition to the algometer measurements, the smaller. Results are reported as incidence rate ratios person applying the algometer also subjectively (IRR), which can be interpreted as the increase, or graded the calf’s pain response

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idence rate ratios person applying the algometer also subjectively (IRR), which can be interpreted as the increase, or graded the calf’s pain response as low, moderate, reduction, in the rate of the behaviour per minute high or extreme. The methods and results for this sub- per calf, compared to a reference category. An IRR > jective assessment are presented in Supplementary 1.0 indicates an increase in the rate of a behaviour Information 2.3 (i.e. more painful), and IRR < 1.0 indicates a reduction in the rate of a behaviour (i.e. less painful). No differences were noted between 0, 1 and 3 hours Weight gain after disbudding, so these results were re-categorised All calves were weighed on electronic weigh scales on as 0–3 hours after disbudding. Further analyses of the Days 7 and 28. For the Day 7 visit the calibration of the three behavioural responses were carried out using scales was identified as being incorrect for 30 calves similar models to compare results for calves sedated and these animals were removed from weight analysis or not, treated with meloxicam or not, and topical for Day 7, but were included in the analysis for Day 28. anaesthetic or not. Pain sensitivity Statistical analyses A small subset of calves had an extreme subjective pain The sample size for total numbers of enrolled animals response in which they head-butted the algometer, was estimated based on 95% confidence with 80% resulting in a very high algometer reading. As these power of detecting a weight gain difference between values would bias the results, they were removed groups, over 28 days, of 2 kg with a variance of 49 kg. from the analysis. Results from algometer readings This resulted in 284 calves being required across six recorded at the four locations on each calf were

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m the analysis. Results from algometer readings This resulted in 284 calves being required across six recorded at the four locations on each calf were groups. An extra 80 calves were enrolled due to the included in the analysis, and measurements recorded 3 https://doi.org/10.1080/00480169.2019.1640651. 300 E. CUTTANCE ET AL. at different times were re-categorised as 0–1, 2–5, 6–11 Table 3. Number of calves enrolled on three farms in six and 12–24 hours after disbudding. different treatment groups used to investigate the effect of a A linear mixed model, with calf as a random effect, topical anaesthetic (TA) on dairy calves following cautery disbudding. was used to analyse the algometer readings. As it Farm was likely that sedated calves would be poorly respon- Treatment 1 2 3 Total sive immediately after disbudding, treatment groups Crate-control 10 6 47 63 were initially collapsed into sedated and non-sedated, Crate-meloxicam 10 6 46 62 and an interaction term for time and sedation status Crate-TA 10 6 46 62 Sedation-control 10 6 44 60 was added to the model. A subset analysis was then Sedation-meloxicam 9 6 43 58 performed with results from 0–1 hours removed, with Sedation-TA 10 6 43 59 Total 59 36 269 364 the six treatment groups, farm, location on the calf and time as fixed effects. Starting with a full model, fixed effects were dropped from the model if the log- likelihood ratio test between two nested models had calf that aspirated wood chips whilst under sedation a significance of p > 0.05. Model diagnostics were and eight were found to be polled. One further calf examined to assess for outliers and influential lost weight between Day 7 and 28, it was found that observations. this animal had been examined by a veterinarian on An important

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liers and influential lost weight between Day 7 and 28, it was found that observations. this animal had been examined by a veterinarian on An important assumption of linear modelling is that the morning of Day 7 and had been identified with the variation of the residuals is constant across all diarrhoea and ill-thrift. It was in the sedation-meloxi- ranges of the predicted outcomes and associated risk cam group on Farm 3 and was excluded from the factors. With this study, the variation in algometer read- analysis. ings varied considerably between farms, with the alg- ometer readings being greater in Farm 1 than Farms Behavioural responses 2 and 3, as was the variation in the readings. This was corrected by modelling different variance weightings Behavioural responses were recorded and analysed for for each farm, thereby ensuring each farm had equal 20, 30 and 44 calves, on Farms 1, 2 and 3, respectively, weighting when standard errors were used to across eight time periods. compare farms. Ear flicks Weight gain The median number of ear flicks per minute for calves Weight gain was calculated for each calf as the in each treatment group over time are presented in average daily gain (ADG) between Days 0 and 7, and Figure 3a. Results of the final model for variables associ- between Days 0 and 28. Linear regression multivari- ated with the number of ear flicks per minute are able models were used to analyse the ADG for each shown in Table 4. Compared to calves in the crate- time period, including the explanatory variables of control group, the number of ear flicks per minute farm, treatment group and weight at enrolment. An were reduced in all other treatment groups (p ≤ interaction term between treatment group and farm 0.006). The effect was similar for calves

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rolment. An were reduced in all other treatment groups (p ≤ interaction term between treatment group and farm 0.006). The effect was similar for calves treated with was also included in the original multivariable meloxicam or topical anaesthetic. model, as it was biologically plausible that the treat- The number of ear flicks per minute varied with time ments could have different effects on different after disbudding (p < 0.001), increasing from 5–9 hours farms. Starting with a full model that included the after disbudding, decreasing at 12 hours when the interaction term, fixed effects were removed from majority of the calves were sleeping, then increasing the model if the log-likelihood ratio test between again at 22 hours following disbudding. There was no two nested models had a significance of p > 0.05. interaction between time and treatment group on Model diagnostics were examined to assess for out- the number of ear flicks per minute, indicating that liers and influential observations. the effect of treatment did not vary with time after All statistical analyses were carried out using R v3.3.3 disbudding. (R Core Team, 2017; R Foundation for Statistical Com- The number of ear flicks per minute was higher in puting, Vienna, Austria), apart from the negative bino- calves from Farm 1 than calves from the other two mial modelling, that was carried out using Stata 13 farms (p ≤ 0.007), but there was no interaction (StataCorp, College Station, TX, USA) between farm and treatment group. Head scratches Results The median number of head scratches per minute for The number of calves enrolled in each treatment calves in each treatment group over time are presented group on the three farm is presented in Table 3. in Figure 3b. Results of the final model

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atment calves in each treatment group over time are presented group on the three farm is presented in Table 3. in Figure 3b. Results of the final model for variables Nine calves were excluded following enrolment; one associated with the number of head scratches per NEW ZEALAND VETERINARY JOURNAL 301 Table 4. Results of the mixed effects negative binomial regression model for variables associated with the number of ear flicks per minute recorded in dairy calves (n = 94) on three farms between 0–22 hours following cautery disbudding, that were allocated to six treatment groups (see Table 1). Variable IRR 95% CI P-valuea Intercept 0.04 0.03–0.06 <0.001 Farm Farm 1 Ref Farm 2 0.63 0.46–0.87 0.005 Farm 3 0.66 0.49–0.89 0.007 Time (hours) 0–3 Ref 5 1.96 1.54–2.46 <0.001 7 2.29 1.85–2.84 <0.001 9b 3.65 2.56–5.20 <0.001 12 0.18 0.12–0.28 <0.001 22 2.16 1.75–2.66 <0.001 Treatment Crate-control Ref Crate-meloxicam 0.55 0.37–080 0.002 Crate-TAc 0.54 0.37–0.78 0.001 Sedation-control 0.58 0.40–0.86 0.006 Sedation-meloxicam 0.59 0.41–0.85 0.004 Sedation-TA 0.22 0.14–0.33 <0.001 a Significance of incidence rate ratio (IRR). b The number of ear flicks per minute was 3.65 (95% CI = 2.56–5.20) times greater at 9 hours than at 0–3 hours. c The number of ear flicks per minute was 0.54 (95% CI = 0.37–0.78) times lower in calves treated with topical anaesthetic following disbudding in a crate than calves not treated with topical anaesthetic. IRR = Incident rate ratio; Ref = reference category; TA = topical anaesthetic. Overall, the number of head scratches per minute was reduced by 53 (95% CI = 35–67)% in sedated calves compared to non-sedated calves across the 24-hour period (p < 0.001). Table 5. Results of the mixed effects negative binomial

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35–67)% in sedated calves compared to non-sedated calves across the 24-hour period (p < 0.001). Table 5. Results of the mixed effects negative binomial regression model for variables associated with the number of head scratches per minute recorded in dairy calves (n = 94) on three farms between 0–22 hours following cautery disbudding, that were allocated to six treatment groups (see Table 1). Variable IRR 95% CI P-valuea Intercept 0.002 0.001–0.003 <0.001 Figure 3. Median number of (a) ear flicks, (b) head scratches Farm Farm 1 Ref and (c) head shakes per minute recorded in calves after disbud- Farm 2 0.44 0.27–0.71 0.001 ding in crates with no further treatment (red solid line), or were Farm 3 0.51 0.33–0.78 0.002 treated with meloxicam (brown dotted line), or a topical anaes- Time (hours) thetic (green dashed line), or were sedated with no further 0–3 Ref 5 1.98 1.25–3.14 0.004 treatment (turquoise dashed line), or were also treated with 7 1.60 1.06–2.42 0.026 meloxicam (blue dotted line), or a topical anaesthetic (pink 9b 2.85 1.58–5.14 <0.001 dashed line). 12 0.38 0.17–0.85 0.019 22 1.55 1.02–2.34 0.038 Treatment minute is shown in Table 5. For calves that were dis- Crate-control Ref Crate-meloxicam 1.04 0.58–1.84 0.906 budded while restrained in a crate, the addition of melox- Crate-TA 1.15 0.66–2.01 0.63 icam or topical anaesthetic did not reduce the number of Sedation-control 0.62 0.35–1.11 0.105 Sedation-meloxicam 0.47 0.26–0.85 0.013 head scratches per minute (p > 0.6), however treatment Sedation-TAc 0.44 0.23–0.83 0.011 with meloxicam and topical anaesthesia in addition to a Significance of incidence rate ratio (IRR). b sedation reduced the number of head scratches per The number of head scratches per minute was 2.85 (95% CI

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ignificance of incidence rate ratio (IRR). b sedation reduced the number of head scratches per The number of head scratches per minute was 2.85 (95% CI = 1.58–5.14) times greater at 9 hours than at 0–3 hours. minute compared to calves in the crate-control group c The number of head scratches per minute was 0.44 (95% CI = 0.23–0.83) (p ≤ 0.013). The number of head scratches per minute times lower in sedated calves treated with topical anaesthetic following disbudding than calves not treated with topical anaesthetic following dis- was higher in calves from Farm 1 than calves from budding in a crate. Farms 2 or 3 (p ≤ 0.002). IRR = Incident rate ratio; Ref = reference category; TA = topical anaesthetic. 302 E. CUTTANCE ET AL. Table 6. Mean (min, max) algometer readings (N) for all pain sensitivity measurements in dairy calves (n = 124) on three farms between 0–24 hours following cautery disbudding, that were allocated to six treatment groups (see Table 1). Treatment 0–1 hour 2–5 hours 6–11 hours 12–24 hours Crate-control 25.7 (0.2, 73.2) 17.5 (0.6, 79.8) 16.1 (0.2, 66.0) 24.6 (2.4, 83.2) Crate-meloxicam 21.9 (0, 70.2) 21.3 (1.0, 87.6) 18.6 (0.6, 86.8) 25.8 (1.6, 66.8) Crate-TA 27.4 (0, 64.8) 22.0 (0.2, 76.4) 17.7 (0.4, 61.0) 25.2 (1.6, 66.8) Sedation-control 38.6 (11.7, 86.0) 26.7 (3.6, 77.6) 22.2 (0.2, 82.4) 29.9 (3.4, 79) Sedation-meloxicam 40.8 (3.6, 89.2) 31.8 (2.0, 93.8) 25.2 (0.2, 99.8) 29.9 (3.4, 89.0) Sedation-TA 42.5 (4.2, 94.6) 36.4 (3.4, 100.4) 23.5 (1.4, 84.2) 30.0 (2.8, 84.0) TA = Topical anaesthetic. Head shakes sedated calves before they showed a withdrawal The median number of head shakes per minute over response compared to calves that were disbudded time for the six treatment groups are presented in and restrained in the crate (p <

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es per minute over response compared to calves that were disbudded time for the six treatment groups are presented in and restrained in the crate (p < 0.001). Calves in all Figure 3c. In the final mixed effects Poisson regression the sedation groups had a greater force applied model there was an interaction between treatment before they responded than the calves in the crate- group and time (p < 0.01). Therefore the overall effect control group (p < 0.01), however responses were of treatment group could not be reported. similar between calves that were given meloxicam For all times from 0 to 12 hours, there was no stat- or topical anaesthetic in either the crate or sedation istically significant difference in the IRR for each treat- groups. There was no statistically significant differ- ment group (p = 0.29). However, at 22 hours, the ence between pain sensitivity in calves in the number of head shakes per minute differed crate-meloxicam or crate-topical anaesthesia between treatment groups; compared to calves in groups in comparison to the crate-control group (p the crate-control group, the IRR for calves in the > 0.4). crate-topical anaesthesia group was 0.43 (95% CI = The force required to elicit a response was lower 0.20–0.91), for calves in the sedation-control group between 6–11 hours after disbudding compared to was 0.47 (95% CI = 0.22–0.99) and for sedation- 22–24 hours after disbudding, indicating a reduced topical anaesthesia group was 0.16 (95% CI = 0.06– pain sensitivity by 24 hours. 0.38). The number of head shakes per minute was similar for calves in the crate-control and crate- meloxicam (p = 0.93) and sedation-meloxicam (p = 0.08) groups. The number of head shakes per Table 7. Results of the linear regression model for variables

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xicam (p = 0.93) and sedation-meloxicam (p = 0.08) groups. The number of head shakes per Table 7. Results of the linear regression model for variables associated with algometer readings (N) for pain sensitivity minute differed between farms (p < 0.001). recorded in dairy calves (n = 1,828 measurements from 124 calves) on three farms between 2–24 hours following cautery disbudding, that were allocated to six treatment groups (see Pain sensitivity Table 1). Variable Estimate 95% CI P-valuea A total of 2,469 algometer test results from 29, 36 and Intercept 15.52 59 calves on Farms 1, 2 and 3, respectively, were used Treatment in the analysis. The raw means and range of all Crate-control Ref Crate-meloxicam 1.09 −3.63–5.80 0.65 measurements recorded at each time period, across Crate-TA 1.89 −2.98–6.75 0.45 all farms, for each of the six treatment groups are pre- Sedation-control 6.5 1.64–11.35 0.01 Sedation-meloxicam 8.48 3.61–13.35 <0.001 sented in Table 6. Because they had an extreme pain Sedation-TAb 9.10 4.30–13.90 <0.001 response, and an algometer reading > 40 N, 25 test Farm results from nine calves on the three farms were Farm 1 Ref Farm 2 −3.5 −7.23–0.23 0.07 removed from further analyses. Farm 3 15.42 11.92–18.92 <0.001 For the model comparing pain sensitivity between Time (hours) 12–24 Ref sedated and non-sedated calves there was an inter- 2–5 2.82 1.41–4.24 <0.001 action between time and treatment (p < 0.001). At 0– 6–11c −5.31 −6.37 to −4.25 <0.001 Location 1 hours, calves that had been disbudded under seda- Left top Ref tion had 15.8 (95% CI = 13.2–18.5) N greater force Left side −5.53 −6.80 to −4.25 <0.001 applied to the disbudding wound before they Right top 4.85 3.56–6.13 <0.001 Right side −1.03

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.5) N greater force Left side −5.53 −6.80 to −4.25 <0.001 applied to the disbudding wound before they Right top 4.85 3.56–6.13 <0.001 Right side −1.03 −2.31–0.25 0.11 responded compared to calves that were disbudded a Significance of estimate. b and restrained in the crate (p < 0.001). The force required to elicit a pain response was 9.10 (95% CI = 4.30–13.90) The results of the linear regression model for pain N greater for sedated calves treated with topical anaesthetic following disbudding than for calves not treated with topical anaesthetic following sensitivity after measurements from 0–1 hours had disbudding in a crate. c been excluded are presented in Table 7. There was The force required to elicit a pain response was 5.31 (95% CI = 4.25–6.37) N less for calves tested between 6–11 hours after disbudding than for still a significant effect of sedation, with a mean 6.5 calves tested at 22–24 hours. (95% CI = 1.6–11.4) N greater force being applied to Ref = reference category; TA = topical anaesthetic. NEW ZEALAND VETERINARY JOURNAL 303 Weight gain (Anil et al. 2002). Behavioural responses such as those measured in this study are an accepted indicator of The ADG of calves between Days 0–7 was analysed in pain resulting from a disbudding procedure (Faulkner 310 calves and between Days 0–28 in 315 calves. and Weary 2000; Stafford et al. 2003; Heinrich et al. 2010). The behavioural observations provided an Days 0–7 important insight into the behaviour of calves for Average daily gain between Days 0–7 varied between 24 hours following disbudding. Despite the use of a the treatment groups (Supplementary Table 2)4, with cornual nerve block, the observations of ear flicks, the ADG of calves in the sedation-meloxicam group head shakes

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roups (Supplementary Table 2)4, with cornual nerve block, the observations of ear flicks, the ADG of calves in the sedation-meloxicam group head shakes and head scratches indicated that the being 0.14 (95% CI = 0.015–0.274) kg/day greater pain experienced by calves in the first 24 hours after than calves in the crate-control group. Growth rates disbudding was substantial. were similar between farms, and there was no inter- Both the use of meloxicam or topical anaesthetic action between treatment group and farm. Weight resulted in a reduction of ear flicks, in calves that at enrolment was not associated with ADG between were disbudded in a crate or sedated. However, the Days 0–7. most pronounced reduction was seen in calves When comparing sedated and non-sedated calves, treated with the combination of sedation and topical the ADG of calves disbudded under sedation was 0.10 anaesthetic which resulted in a 78% reduction in ear (95% CI = 0.02–0.17) kg/day more than calves dis- flicks and a 56% reduction in head scratches relative budded in a crate (p = 0.009). However there was to calves disbudded in a crate without sedation. The no overall effect of either topical anaesthesia (p = equivalent reduction in calves treated with meloxicam 0.50), or meloxicam (p = 0.75) on ADG between plus sedation was 41% and 53% for ear flicks and head Days 0–7. scratches, respectively. It is possible that because calves within the six treat- Days 0–28 ment groups were observed for behavioural responses The ADG of calves between Days 0–28 varied between within the same pen, there could be a perceived lack of farms (p < 0.05), but there was no farm by treatment independence between calves. For healthy calves not interaction (p = 0.73; Supplementary Table 3).4 The experiencing

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ut there was no farm by treatment independence between calves. For healthy calves not interaction (p = 0.73; Supplementary Table 3).4 The experiencing pain, if a particularly active calf was ADG of calves in the sedation-topical anaesthetic present it may influence the behaviour of other group tended to be greater than calves in the crate- calves in a pen. However in this study very specific control group by 0.06 (95% CI=−0.01–0.13) kg/day (p behaviour responses were assessed that have been = 0.09). There was no statistically significant difference demonstrated to be indicators of pain (Faulkner and in ADG between any of the other treatment groups Weary 2000; Stafford et al. 2003; Heinrich et al. 2010). compared to the crate-control group. It was considered very unlikely that ear flicks, head When comparing sedated and non-sedated calves, scratches or head shakes of one calf would influence the ADG of sedated calves was 0.05 (95% CI = 0.01– the expression of these behaviours in other calves 0.09) kg/day greater than non-sedated calves (p = within a pen, so they were treated as independent 0.01). There was no overall effect of either topical observations. anaesthetic (p = 0.82), or meloxicam (p = 0.74), on Practically, these results suggest that if calves are ADG between Days 0–28. disbudded by lay disbudding operations or by farmers (who cannot use sedation), there is some benefit of using topical anaesthetic or meloxicam, but Discussion to minimise the pain-associated behaviours after dis- This study is one of the largest studies conducted on budding, sedation is required. This study has provided disbudding and showed that there was a positive some evidence (based on ear flicks and head shakes) effect of disbudding under sedation on all outcomes

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disbudding and showed that there was a positive some evidence (based on ear flicks and head shakes) effect of disbudding under sedation on all outcomes that adding topical anaesthetic to a disbudding pro- measured. There was a benefit to providing calves cedure that involved sedation reduced the expression with topical anaesthetic or meloxicam following dis- of pain-associated behaviours compared to use of budding on behavioural responses and pain sensitivity. meloxicam. In addition there appeared to be an The benefit of topical anaesthetic was not statistically extended effect of topical anaesthetic in reducing the different to that of meloxicam except for a reduction number of head shakes at 22 hours in calves dis- in ear flicks in sedated calves. budded with and without sedation. Sedation alone Pain can be difficult to measure as it is a subjective also reduced the number of head shakes at this time, state. However behaviour can be a sensitive indicator but the use of meloxicam did not. of pain, over and above that of concentrations of corti- The benefit of sedation may be a direct effect of the sol in serum and other physiological measures analgesic effect of xylazine, the moderation of 4 https://doi.org/10.1080/00480169.2019.1640651. 304 E. CUTTANCE ET AL. hyperalgesia or reduced anxiety (Garcia-Villar et al. with the pressure algometer, was only apparent in 1981; Browning et al. 1982), but there are some other calves that were sedated and was comparable reasons for the strong effect of sedation seen in this between the two products, and were similar to those study. Firstly, to simplify study management, the of calves that that were only sedated. These results sedated calves were kept separate from the unsedated were supported by the subjective pain

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t, the of calves that that were only sedated. These results sedated calves were kept separate from the unsedated were supported by the subjective pain assessment, calves. This meant that one technician provided the where sedated calves had significantly reduced odds cornual nerve block to sedated calves and another to of showing high or extreme responses compared the calves disbudded in a crate. Thus it is possible with unsedated calves. that this confounding between sedation and tech- The effect of providing pain relief using NSAID on nician could have contributed to the apparent effect weight gain after disbudding was investigated in two of sedation if their techniques were different. studies (Bates et al. 2015, 2016), which found that treat- However the technicians were extremely experienced ment with meloxicam or ketoprofen was associated and trained annually to the veterinary clinic’s standard with increased weight gain only in animals disbudded operating procedure, and had also been retrained by without sedation or local anaesthetic. There was no the supervising veterinarian prior to study start. Fur- benefit if NSAID were used alongside sedation and thermore the effectiveness of all the cornual nerve local anaesthetic. In contrast the present study blocks were checked prior to disbudding. Another showed a significant increase in weight gain in the potential reason for the apparent benefit of sedation first 7 days after disbudding, only in sedated calves was that it would have been easier to administer the treated with meloxicam compared to the crate- nerve block in calves that were sedated than restrained control group. However, these results are not directly in a crate. Therefore the benefits observed after disbud- comparable with those of the

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estrained control group. However, these results are not directly in a crate. Therefore the benefits observed after disbud- comparable with those of the previous studies, as in ding may have been due to more effective analgesia the present study all animals had a cornual nerve during the disbudding and not necessarily just the block which could have reduced any potential impact effect of xylazine. Responses of calves during disbud- of meloxicam on growth rates. Nevertheless, our ding were not recorded, and were only used as an indi- results are consistent with those of Bates et al. (2015, cation that an animal did not have an effective block 2016) as the increased growth rates recorded in the 7 (as per the disbudding protocol), but could have had days after disbudding in sedated calves treated with a relationship with the subsequently recorded meloxicam (0.144 kg/day) were only marginally responses. greater than the increase seen in calves in the seda- Although there are no suitable comparable studies tion-control group (0.125 kg/day). This finding supports on the use of a topical anaesthetic following disbud- the suggestion that the use of xylazine sedation alone ding with a cornual nerve block, the results are compar- may increase weight gain after disbudding (Bates et al. able to other studies that have investigated 2015, 2016). behavioural responses following the use of NSAID. One of the practical considerations of using the Heinrich et al. (2010), compared the use of meloxicam topical anaesthetic was that it was a liquid. In the and a placebo following disbudding with a cornual study, the product was applied and any surplus liquid nerve block and reported reductions in ear flick per was caught on a towel before the calf was released. hour of 70% and 83% with

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nd any surplus liquid nerve block and reported reductions in ear flick per was caught on a towel before the calf was released. hour of 70% and 83% with meloxicam 0 and 1 days This may possibly have given a longer contact time after disbudding, respectively. There was also a 74% for the product, but it is unknown if this would affect reduction in head shakes but no reduction in head how well it was effective. scratches. Faulkner and Weary (2000) compared behav- Management of animal welfare needs to be at the ioural responses in calves disbudded with a cornual forefront of our dairy industry and this study has nerve block and sedation as well as treated with keto- given a strong indication that, until we are able to pre- profen with calves not treated with ketoprofen. They dominantly breed polled calves, more can be done to found a significant reduction in the frequency of ear alleviate pain and suffering following the disbudding flicks, head shakes and head rubs during the 24 hours procedure. The positive results shown from the use of after disbudding in calves treated with ketoprofen. the topical anaesthetic in combination with sedation These results, as well as our study results, indicate indicate that this product produces an effective that the behavioural responses of calves who received reduction in indicators of pain, similar to those result- topical anaesthetic was comparable to the behavioural ing from use of NSAID. responses of calves who received NSAID. In conclusion, there was a positive effect of disbud- The use of pressure algometry has previously been ding calves under sedation on all outcomes. There was used in adult cattle to objectively assess pain associ- a benefit to providing calves with topical anaesthetic ated with skin lesions of lame

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There was used in adult cattle to objectively assess pain associ- a benefit to providing calves with topical anaesthetic ated with skin lesions of lame cattle (Dyer et al. 2007) following disbudding on behavioural responses and as well as to assess the pain associated with dehorning. pain sensitivity and this benefit was not statistically (Heinrich et al. 2010). The effect of topical anaesthetic different to that of treatment with meloxicam. The and meloxicam on the pain sensitivity, as measured effects were most pronounced when topical NEW ZEALAND VETERINARY JOURNAL 305 anaesthetic was applied in calves that were disbudded Espinoza C, Lomax S, Windsor P. The effect of a topical under sedation and indicate that the effect may last at anesthetic on the sensitivity of calf dehorning wounds. Journal of Dairy Science 96, 2894–902, 2013 least 22 hours following the disbudding procedure. Faulkner PM, Weary DM. Reducing pain after dehorning in dairy calves. Journal of Dairy Science 83, 2037–41, 2000 Acknowledgements Garcia-Villar R, Toutain P, Alvinerie M, Ruckebusch Y. The pharmacokinetics of xylazine hydrochloride: an inter- The authors would like to thank Bayer New Zealand Ltd for specific study. Journal of Veterinary Pharmacology and funding the study, the farm animal owners, managers and Therapeutics 4, 87–92, 1981 workers for all the time they spent drafting, helping make Heinrich A, Duffield TF, Lissemore KD, Millman ST. The pens and finally the amazing VetEnt technicians and vets effect of meloxicam on behavior and pain sensitivity of for their organisation, flexibility and most of all, enthusiasm. dairy calves following cautery dehorning with a local anes- thetic. Journal of Dairy Science 93, 2450–7, 2010 McCarthy D, Windsor PA, Harris C, Lomax S,

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iry calves following cautery dehorning with a local anes- thetic. Journal of Dairy Science 93, 2450–7, 2010 McCarthy D, Windsor PA, Harris C, Lomax S, White PJ. ORCID Effect of topically applied anaesthetic formulation on the sensitivity of scoop dehorning wounds in calves. PLOS EL Cuttance http://orcid.org/0000-0003-0354-5295 ONE 11, e0163181, 2016 DA Yang http://orcid.org/0000-0003-3893-9403 McMeekan C, Stafford KJ, Mellor DJ, Bruce RA, Ward RN, RA Laven http://orcid.org/0000-0002-8938-8595 Gregory N. Effects of a local anaesthetic and a non-ster- oidal anti-inflammatlory analgesic on the behavioural responses of calves to dehorning. New Zealand Veterinary References Journal 47, 92–6, 1999 *Anonymous. Animal Welfare (Care and Procedures) Petrie NJ, Mellor DJ, Stafford KJ, Bruce RA, Ward RN. Regulations 2018 http://www.legislation.govt.nz/ Cortisol responses of calves to two methods of disbudding regulation/public/2018/0050/latest/096be8ed817efd82. used with or without local anaesthetic. New Zealand pdf (accessed 1 June 2019). New Zealand Government, Veterinary Journal 44, 9–14, 1996 Wellington, NZ, 2018 Stafford KJ, Mellor DJ, Todd SE, Ward RN, McMeekan CM. Anil SS, Anil L, Deen J. Challenges of pain assessment in The effect of different combinations of lignocaine, ketopro- domestic animals. Journal of the American Veterinary fen, xylazine and tolazoline on the acute cortisol response Medical Association 220, 313–9, 2002 to dehorning in calves. New Zealand Veterinary Journal 51, Bates AJ, Eder P, Laven RA. Effect of analgesia and anti- 219–26, 2003 inflammatory treatment on weight gain and milk intake Sutherland MA, Mellor DJ, Stafford KJ, Gregory NG, Bruce of dairy calves after disbudding. New Zealand Veterinary RA, Ward RN. Cortisol responses

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ntake Sutherland MA, Mellor DJ, Stafford KJ, Gregory NG, Bruce of dairy calves after disbudding. New Zealand Veterinary RA, Ward RN. Cortisol responses to dehorning of calves Journal 63, 153–7, 2015 given a 5-h local anaesthetic regimen plus phenylbuta- Bates A, Laven R, Chapple F, Weeks D. The effect of zone, ketoprofen, or adrenocorticotropic hormone prior different combinations of local anaesthesia, sedative and to dehorning. Research in Veterinary Science 73, 115–23, non-steroidal anti-inflammatory drugs on daily growth 2002 rates of dairy calves after disbudding. New Zealand Van der Saag D, Lomax S, Windsor PA, Taylor C, White PJ. Veterinary Journal, 64, 282–7, 2016 Evaluating treatments with topical anaesthetic and buccal Browning S, Lawrence D, Livingston A, Morris B. meloxicam for pain and inflammation caused by amputa- Interactions of drugs active at opiate receptors and drugs tion dehorning of calves. PLOS ONE 13 e0198808, 2018a active at α2receptors on various test systems. British Van der Saag D, White P, Ingram L, Manning J, Windsor P, Journal of Pharmacology 77, 487–91, 1982 Thomson P, Lomax S. Effects of topical anaesthetic and Dyer RM, Neerchal NK, Tasch U, Wu Y, Dyer P, buccal meloxicam treatments on concurrent castration Rajkondawar PG. Objective determination of claw pain and dehorning of beef calves. Animals 8, 35, 2018b and Its relationship to limb locomotion score in dairy Verbeke W. Stakeholder, citizen and consumer interests in cattle. Journal of Dairy Science 90, 4592–602, 2007 farm animal welfare. Animal Welfare 18, 325–33, 2009 * Non-peer-reviewed.