Effects of regional analgesia and/or a non-steroidal anti-inflammatory analgesic on the acute cortisol response to dehorning in calves

Cold therapy and pain relief after hot-iron disbudding in dairy calves

Even when pain control is implemented, calves may experience pain for days after hot-iron disbudding. Whether calves seek pain relief post-disbudding offers a novel approach to assessing pain in these animals. By employing an approach-aversion paradigm, we explored the ability of cold therapy to provide immediate pain relief in disbudded calves. Calves were habituated to the manual placement of a cool or ambient pack on their forehead for a short duration simultaneous to milk reward consumption, prior to disbudding. Calves were then disbudded under local anaesthesia (procaine) and analgesia (meloxicam), and responses to the packs were observed over subsequent days. Individual calves were consistently exposed to either cool or ambient packs in different halves of a two-sided experimental pen, allowing for the testing of approach-aversion and conditioned place preference. We found calves approached milk rewards quicker and maintained contact for longer when receiving cold therapy compared to the ambient control. However, calves did not display any conditioned preference for the pen where they received the cool pack. These results add to the growing evidence of lasting pain following disbudding procedures and suggests that cold therapy provides some form of pain relief post-disbudding. Future studies should seek other ways to use cold therapy post-disbudding to reduce aversiveness and human involvement.

Multi-dimensional evaluation of pain response in low day-age calves to two types of dehorning

Introduction

Dehorning calves is necessary to minimize injury because intensive raising circumstances make horned cows more aggressive. However, acute pain is commonly perceived by farm animals when undergoing painful practices such as dehorning, affecting their health status and quality of life. By quantifying the magnitude of pain and discomfort associated with dehorning, we aim to contribute to a more humane and sustainable cattle farming industry.

Methods

The objective of this study was to evaluate the behavioral, physiological, and emotional effects of acute dehorning pain in calves using two methods: dehorning cream and dehorning hot-iron.30 Holstein calves aged 4 days were selected for the study. These calves were randomly assigned to two experimental groups based on the method of disbudding: dehorning cream (n = 15) and hot-iron dehorning (n = 15). Before and after dehorning, we evaluated their physiological indicators of infrared eye temperature, concentrations of substance P, IL-6, cortisol, haptoglobin, as well as emotional state, and pain-related behavioral reactions.

Results

Post-dehorning, the duration of lying down decreased significantly in both groups (DI and DC: 0-4 h) after dehorning (p < 0.05). Both groups exhibited increased frequencies of pain-related behaviors such as head shaking (DI: 1-7 h, DC: 1-6 h), ear flicking (DI: 2-7 h, DC: 2-7 h), head scratching (DI: 2-3 h, DC: 1-7 h), and top scuffing (DI: 2 h, DC: 2-7 h) compared to pre-dehorning (p < 0.05). The DC group demonstrated a higher frequency of head-shaking, ear-flicking, head-scratching, and top-rubbing behaviors, along with a longer duration of lying down (0-4 h), compared to the DI group (p < 0.05). Post-dehorning, play behavior reduced significantly in both groups (6-8 h) (p < 0.05), whereas judgment bias and fear levels showed no significant change (p > 0.05). Physiological measures including eye temperature, and blood levels of substance P and IL-6, did not differ significantly between the groups before and after dehorning (p > 0.05). However, 48 h after dehorning, calves in the DC group had significantly higher haptoglobin levels compared to the DI group (p = 0.015). Additionally, salivary cortisol levels in the DC group increased significantly at 3.5 h and 7 h post-dehorning (p = 0.018, p = 0.043).

Discussion

Both hot-iron and cream dehorning induced pain in calves, as evidenced by increased pain-related behaviors, elevated salivary cortisol, and higher haptoglobin levels, alongside reduced positive behaviors. Notably, these effects were more pronounced in the DC group than in the DI group, suggesting that dehorning hot-iron may be a comparatively less stressful dehorning method for young calves. Moreover, the brief duration of pain response and weaker response to dehorning observed in 13-day-age calves in this study suggests that dehorning at younger ages may be more advisable and warrants further research.

Exploring the effect of pain on response to reward loss in calves

Negative emotional states are known to interact, potentially aggravating one another. In this study, we used a well validated paradigm (successive negative contrast, SNC) to determine if pain from a common procedure (disbudding) influences responses to a reward downshift. Holstein calves (n = 30) were trained to approach a 0.5 L milk reward. Latency to approach, number of vocalisations and pressure applied on the bottle were recorded during training. To assess how pain affected responses to reward downshift, calves were randomly assigned to one of three treatments before the downshift. Two groups were disbudded and provided the 'gold standard' of pain mitigation: intraoperative local anesthesia and analgesia. One of these disbudded groups was then provided supplemental analgesic before testing. The third group was sham disbudded. All calves were then subjected to the reward downshift by reducing the milk reward to just 0.1 L. Interactions were detected between test session and daily trials on pressure applied for the Disbudded group (estimate ± SEM: 0.08 ± 0.05), and on vocalisations for the Sham (0.3 ± 0.1) and Disbudding + Analgesia (0.4 ± 0.1) groups. Our results indicate that SNC is a promising paradigm for measuring negative affect in calves and suggests that pain potentially affects the response to a reward downshift.

A Clinical Trial on the Welfare Effects of Administering Meloxicam to 10 to 21 Day Dairy Calves Following Caustic Paste Disbudding

Caustic paste disbudding (CPD) is widely utilized for calves, which has been known to result in adverse effects on the calves and ethical concerns related to animal welfare, despite the use of local anesthetics. The administration of meloxicam has been demonstrated to provide benefits in alleviating pain and inflammation in juvenile calves under 9 d old and subjected to CPD. Nonetheless, there is a scarcity of literature documenting the beneficial impact of meloxicam in alleviating pain in calves aged over 9 d that have undergone CPD. Therefore, the objective of this clinical trial was to evaluate the efficacy of administering meloxicam and lidocaine for cornual nerve block together in mitigating the deleterious effects of CPD, as opposed to using lidocaine alone in calves older than 9 d. Thirty Holstein calves, aged between 10 and 21 d, were enrolled and randomly assigned to 1 of 2 treatments: lidocaine alone (Placebo), lidocaine and normal saline treatment before CPD, and lidocaine plus meloxicam, lidocaine and 0.5 mg/kg of meloxicam treatment prior to CPD. The researchers were blind to the treatment of calves to control the subjective error. The occurrences of actions associated with pain, which included head shaking, head rubbing, ear flicking, tail flicking, kicking, and head passing through the fence, were recorded. Physiological performance, including the respiration rate, heart rate, rectal temperature, mechanical nociceptive threshold (MNT), food intake, and daily activity level, was monitored. Hematological conditions were ascertained through the use of routine blood tests and enzyme-linked immunosorbent assay. The generalized linear mixed model was employed to analyze the data. The research findings revealed that applying the CPD procedure significantly elevated the frequencies of tail flicking, head shaking, and kicking, resulted in increases in respiratory rate, heart rate, daily active steps, and food intake and a decrease in MNT, and led to alterations in hematological markers, including platelet counts, mean platelet volume, prostaglandin E2, constitutive nitric oxide synthase, and hydroxyl radical. Considerable benefits, such as lower heart rates, higher food intake, and MNTs, as well as lower levels of white blood cell counts, lymphocyte counts, hemoglobin, mean platelet volume, prostaglandin E2, tumor necrosis factor-α, constitutive nitric oxide synthase, malondialdehyde, and hydroxyl radical, were observed in the calves that received meloxicam treatment in response to CPD. The findings of the study indicate that the co-administration of lidocaine and meloxicam provides obvious benefits in mitigating pain, inflammation, and oxidative stress in calves aged over 9 d and undergoing CPD. This endorses the use of meloxicam during the disbudding and dehorning procedures of calves.

A novel transdermal ketoprofen formulation for analgesia in cattle

Ketoprofen is registered in many countries for injectable administration in cattle. Because it is soluble in a wide range of excipients, development of a novel transdermal (TD) ketoprofen formulation was pursued to provide a convenient and pain-free route of administration in cattle. One hundred and six excipient combinations were screened using in vitro techniques (Franz diffusion cells), with a 20%_(w/v) ketoprofen formulation dissolved in a combination of 45%:45%_(v/v) ethanol and isopropyl myristate (IPM) and 10%_(v/v) eucalyptus oil achieving maximal penetration of ketoprofen through bovine skin. A bioavailability study was then conducted using a randomized cross-over design (n = 12), including IV, IM (both 3 mg/kg) and TD (10 mg/kg) ketoprofen formulations administered with a one-week washout period between administrations. The IV and IM formulation pharmacokinetic results were as expected. The C_MAX , T_{max and} AUC_0-Last were significantly higher (arithmetic mean ± SD) after TD administration (20.0 ± 6.5 μg/ml, 115 ± 17 min and 3940 ± 1324 μg*min/ml, respectively), compared to IM (11.0 ± 4.0 μg/ml, 74 ± 43 min and 2376 ± 738 μg*min/ml, respectively), although there were no significant differences for T_½β . However, dose corrected values C_MAX and AUC_inf were significantly higher for IM compared to TD. The arithmetic mean bioavailability (F) of the transdermal formulation was 50%. The plasma concentration of the TD formulation at a dose of 10 mg/kg was similar to the IM formulation at 3 mg/kg by 30 min post-dosing with an arithmetic mean ± SD of 7.97 ± 4.38 vs. 8.02 ± 3.55 μg/ml, respectively. The TD formulation was generally well tolerated by cattle, although some local irritation along the site of application was noted after 12 h of exposure during the bioavailability study. Results indicate that this novel TD formulation provides a substantial improvement in administration convenience, may improve animal welfare and end-user safety through needle-free administration, and achieves similar plasma pharmacokinetics to the IM product when administered at 10 mg/kg.

Behavioral and Physiological Response to Routine Thermal Disbudding in Dairy Calves Treated with Transdermal Flunixin Meglumine

Transdermal flunixin meglumine was approved in 2018 to treat pain related to foot-rot in cattle, leading to the question of whether it would be effective as part of a comprehensive pain management strategy for disbudding. To investigate, calves were assigned to three treatment groups: 2% lidocaine cornual nerve block only (L), lidocaine nerve block +0.45 mg/lb (1 mg/kg) oral meloxicam (M), or lidocaine nerve block +1.5 mg/lb (3.3 mg/kg) transdermal flunixin meglumine (F) (n = 61). Ear flicking (p = 0.001), head shaking (p < 0.001), tail flicking (p < 0.001), interaction with the environment (p < 0.001), grooming (p < 0.01), posture changes (p < 0.05), and standing (p < 0.001) were impacted by the time relative to the procedure. Cortisol levels rose post procedure (p < 0.001). There was no difference in rates of behaviors or cortisol between treatments. These results indicate that calves showed alterations in behavior and cortisol in response to disbudding but not between treatments. We conclude that the pain management protocol for disbudding, which included transdermal flunixin meglumine with a lidocaine cornual nerve block, did not show significant differences from protocols using meloxicam with a lidocaine block, or a lidocaine block alone.

Methods for Pain Assessment in Calves and Their Use for the Evaluation of Pain during Different Procedures-A Review

The evaluation and assessment of the level of pain calves are experiencing is important, as the experience of pain (e.g., due to routine husbandry procedures) severely affects the welfare of calves. Studies about the recognition of pain in calves, and especially pain management during and after common procedures, such as castration, dehorning, and disbudding, have been published. This narrative review discusses and summarizes the existing literature about methods for pain assessment in calves. First, it deals with the definition of pain and the challenges associated with the recognition of pain in calves. Then it proceeds to outline the different options and methods for subjective and objective pain assessment in calves, as described in the literature. Research data show that there are several tools suitable for the assessment of pain in calves, at least for research purposes. Finally, it concludes that for research purposes, various variables for the assessment of pain in calves are used in combination. However, there is no variable which can be used solely for the exclusive assessment of pain in calves. Also, further research is needed to describe biomarkers or variables which are easily accessible in the field practice.

Randomized controlled trial assessing the effects of xylazine sedation in 2- to 6-week-old dairy calves disbudded with a cautery iron

The use of local anesthesia and a nonsteroidal anti-inflammatory drug (NSAID) can reduce indicators of pain and inflammation and encourage self-rewarding behavior in calves following disbudding. Although the use of sedation may be recommended as a best practice for disbudding, there is little research in this area. The objective of this study was to evaluate the effects of xylazine sedation in conjunction with a local anesthetic and an NSAID in calves undergoing cautery disbudding. One hundred twenty-two group-housed female and male Holstein calves fed milk with automated feeders, aged 13 to 44 d, were enrolled over 9 replicates and randomly allocated to 1 of 2 treatments: (1) sedated: lidocaine cornual nerve block, 0.5 mg/kg meloxicam (administered subcutaneously) and 0.2 mg/kg xylazine (administered intramuscularly), or (2) nonsedated: lidocaine cornual nerve block and meloxicam. Outcomes collected consisted of feeding behavior (collected using automated milk feeders), latency to drink milk following disbudding, play behavior (induced by adding bedding), lying behavior, mechanical nociceptive threshold (MNT, measured using a pressure force algometer), struggling behavior during disbudding, length of time to administer the nerve block, length of time to disbud, and serum haptoglobin concentrations. Data were analyzed using mixed models with a fixed effect for baseline values and a random effect for trial replicate. Linear regression was used to assess continuous outcomes, logistic regression for binary outcomes, and Poisson and negative binomial models for count data with negative binomial models used if the over dispersion term was significant. There were no detected differences between the treatment groups in mean daily milk consumption in the 72-h following disbudding. Sedated calves had reduced average milk drinking speed from 0 to 24 h and 24 to 48 h following disbudding compared with nonsedated calves, but no difference was detected from 48 to 72 h. Sedated calves had reduced MNT at 0, 60, and 240 min after disbudding, but no differences were detected between groups at 24 h after disbudding. Nonsedated calves had 4.5 times the odds (95% CI: 1.5-13.2) of struggling more than twice during the disbudding procedure compared with sedated calves, and it took less time to administer a nerve block to sedated calves compared with nonsedated. At +3 h, nonsedated calves were 79 times (95% CI: 22.4 to 279.2) more likely to play compared with sedated calves, and 24 h after disbudding, sedated calves were 2 times more likely to play compared with nonsedated calves (95% CI: 0.93-4.3). The results indicate that calves sedated with xylazine for cautery disbudding responded less to painful stimuli (disbudding and MNT) both during and following the procedure and had a higher rate of play behavior 24 h following sedation compared with the nonsedated calves, but xylazine may also have a prolonged carryover effect that affects suckling behavior for 48 h following sedation.

A field trial comparing four oral nonsteroidal anti-inflammatory drugs on controlling cautery dehorning pain and stress in calves

The purpose of this study was to compare the analgesic effect of four nonsteroidal anti-inflammatory drugs (NSAIDs) administered as a single, standardized, oral dose in dairy calves at the time of cautery dehorning. The NSAIDs investigated have pharmacokinetic properties in cattle that produce persistent plasma concentrations that may provide prolonged analgesia with the added practicality of a simple administration regimen. One hundred and eighty-five Holstein calves aged approximately 50 d old were either sham dehorned (n = 31) or cautery dehorned following oral administration of carprofen (n = 31), firocoxib (n = 31), flunixin meglumine (n = 30), meloxicam (n = 31) or placebo (n = 31) in a randomized, controlled trial. A standard dose of 2.0 mg/kg was administered to all calves receiving an oral NSAID. All calves received local anesthesia prior to actual or sham dehorning. Cortisol concentrations, heart rate, mechanical nociception thresholds, ocular and dehorning area temperatures, and average daily gains were evaluated. A linear mixed-effects model with repeated measures was used for statistical analysis. Administration of oral meloxicam, flunixin meglumine, and firocoxib at 2.0 mg/kg resulted in decreased cortisol concentrations compared to placebo-treated controls for the first 24 h postdehorning (AUEC_0–24) (P = 0.03). Moreover, firocoxib, flunixin meglumine, and meloxicam attenuated the maximum cortisol concentrations compared to placebo-treated calves (P = 0.04, P= 0.02). In calves treated with flunixin meglumine, cortisol concentrations was reduced at 4 h (P = 0.04) and 8 h (P = 0.02). In addition, analgesic administration was associated with changes in ocular and dehorning area temperature differences (P = 0.09). Carprofen and meloxicam reduced heart rates during the entire study period (P = 0.003). Although a treatment effect (P < 0.0001) was observed in the determination of mechanical nociception threshold among all treatment groups, meloxicam expressed marginally significant effects (P = 0.09) among NSAID treated groups dehorned. A single dose of oral meloxicam, flunixin meglumine, or firocoxib administered at 2.0 mg/kg reduced the acute stress response associated with cautery dehorning. However, carprofen administration was associated with increased cortisol concentrations and dehorning area temperatures for the initial 24 h. Given the changes in pain and stress outcome variables assessed in this study, NSAIDs should be administered at the time of dehorning.

A Novel Transdermal Ketoprofen Formulation Provides Effective Analgesia to Calves Undergoing Amputation Dehorning

Simple Summary

A transdermal formulation of ketoprofen was developed to provide effective analgesia in cattle undergoing surgical husbandry procedures. Topical administration would reduce the requirement for veterinary presence and be easy to apply to unhandled animals, improving compliance. The transdermal formulation was at least as effective as a commercially available intramuscular formulation in providing analgesia in cattle following dehorning. Efficacy was assessed using plasma cortisol concentrations, bodyweight (BW) gain and behavioural changes. Plasma ketoprofen concentrations were measured in the plasma approximately 20 min after application and peaked at 2 h, suggesting that transdermal ketoprofen had a rapid onset and would provide suitable analgesia if applied when cattle have been penned prior to the procedure being undertaken.

Abstract

There is a critical need to ensure that all cattle undergoing surgical husbandry procedures are provided effective pain relief. Non-steroidal anti-inflammatory drugs (NSAIDs) are most commonly used, and typically are administered by intramuscular (IM) injection. However, administration of NSAIDs via this route to large numbers of cattle which are handled only once or twice a year, typical of many rangeland beef production systems, presents significant occupational health and safety and mis-administration risks. To address this, a novel transdermal (TD) formulation of ketoprofen was developed, and its efficacy assessed in a study of 36 Holstein–Friesian calves which were assigned to a placebo (n = 10), a TD ketoprofen (n = 10), an IM ketoprofen (n = 10) and sham dehorned group (n = 6). TD ketoprofen significantly reduced plasma cortisol concentrations between 1 to 4 h after dehorning compared to placebo treated calves, with concentrations at 2 and 4 h being very similar to those for sham dehorned calves. The expected log count of positively associated pain variables (ear flick, tail wag, ruminating, head shake, lying down, grooming and neck extending) in the TD group was reduced by 42%, compared to placebo calves, with an overall significant (p < 0.05) treatment effect. The IM group exhibited similar responses and both TD and IM cattle had a higher BW gain at 2 and 5 (p < 0.05) weeks post-dehorning, compared to placebo. This study has shown that TD administered ketoprofen was at least as effective as IM to control pain associated with dehorning and facilitates the administration of analgesic drugs prior to the surgical husbandry procedures being performed.

Effect of xylazine administration before laparoscopic abomasopexy to correct left displaced abomasum on markers of stress in dairy cows

Left displacement of the abomasum in dairy cows is a disease diagnosed all over the world. In Germany, a common method for its correction is laparoscopic abomasopexy (LA). The aim of the study was to assess cortisol and substance P concentrations, behavioral patterns, and feeding and rumination times during and after LA in cattle treated with xylazine before LA compared with nonsedated cattle. A total of 28 cattle that had been referred to a veterinary teaching hospital with a diagnosis of left displacement of the abomasum were randomly assigned to 1 of 2 groups. Surgery was performed according to a standardized protocol. Animals of XYL (n = 14) received xylazine (0.02 mg/kg body weight i.v.) before surgery, and animals of CON (n = 14) received a placebo (0.9% saline i.v.). All cows received ketoprofen (3 mg/kg body weight i.v.) twice, and benzyl penicillin procaine (20,000 IU/kg body weight i.m.) for 5 ± 1 d. Blood samples for the determination of plasma cortisol concentration (PCC) and plasma substance P concentration were taken 3 h before surgery (+00:00), at 1100 h (+03:00), 1115 h (+03:15, skin incision), 1130 h (+03:30), 1145 h (+03:45, dorsal recumbency), 1200 h (+04:00, end of surgery), 1230 h (+04:30), 1300 h (+05:00), 1400 h (+06:00), and 1100 h (+27:00) the following day. Behavior was assessed on the day of surgery and the following day (0800, 1300, and 1700 h), and during surgery. Feeding and rumination time were recorded for 24 h after surgery. Data analysis was done using R (R Foundation for Statistical Computing, Vienna, Austria). The LA was performed in all animals without negative effects. The PCC was lower in XYL than in CON at all times and significantly lower at +03:30. In CON, PCC was significantly higher at +03:45, +04:00, and +04:30 compared with +03:00. In XYL, PCC was significantly lower at +03:15 and +03:30 compared with +03:00, and significantly higher at +04:00 and +04:30. Plasma substance P concentration did not differ between groups. No differences were observed in behavior between CON and XYL. Feeding and rumination times did not differ between groups. Animals in XYL showed significantly more chews per bolus after surgery than animals in CON. In conclusion, administration of xylazine before LA results in lower stress levels for cattle during the course of LA, especially before being put into lateral and dorsal recumbency. Therefore, in the opinion of the authors, xylazine administration can be recommended before LA to improve the well-being of the animals during and after surgery.

Differential Transcription of Selected Cytokine and Neuroactive Ligand-receptor Genes in Peripheral Leukocytes from Calves in Response to Cautery Disbudding

Simple Summary

Calf disbudding is a painful husbandry practice on dairy and beef cattle farms. Continuing efforts to enhance the accuracy of pain assessment can aid in the application of effective anti-nociceptive (analgesic) agents in non-verbal animals. The aim of this study was to evaluate the changes in the expression of genes involved in inflammation and pain sensitisation in response to removal of horn buds in calves, using hot-iron cauterization. The efficacy of an analgesic, meloxicam, was also tested in attenuating the changes in expression of the studied genes post-disbudding. It was revealed that cautery disbudding induces significant changes in the expression of genes involved in inflammation. Meloxicam was able to blunt the increased expression of some of the genes at 4 h and 24 h after disbudding, while it could not attenuate the increased expression of a few other genes associated with inflammation.

Abstract

Calf disbudding is a painful husbandry practice on dairy and beef cattle farms. An objective measurement of pain is useful to reliably evaluate the pain intensity and anti-nociceptive (analgesic) efficacy of therapeutic agents. The aim of this study was to investigate the changes in peripheral leucocyte inflammatory cytokine gene expression in calves after disbudding, and to assess whether the changes in cytokine gene expression could be an indicator of the efficacy of analgesic drugs. In a randomised controlled study, 16 calves (aged 31 to 41 days and weighing 58 to 73 kg), undergoing routine disbudding, were randomly allocated into two groups (n = 8 in each group). Calves in the control group received no analgesic, while those in the treatment group received 0.5 mg kg⁻¹ meloxicam subcutaneously prior to disbudding. Disbudding was performed using an electric debudder. Blood (10 mL) was sampled from the jugular vein just before and 4 and 24 h post-disbudding, RNA was extracted from leukocytes, and the transcription of 12 genes of interest was assessed using nCounter gene expression assay. The results showed significantly higher transcription (compared to baseline values) of the studied genes (except CRH, IFNγ, and IL10) in the control group calves at either 4 or 24 h post-disbudding. The administration of meloxicam one hour before disbudding significantly attenuated the upregulation of IL6, PGHS2, TAC1, NOS1, and CRH gene transcription post-disbudding, while it did not suppress the elevated transcription of acute and pro-inflammatory cytokines such as IL1β, IFNγ, IL8, and TNFα genes. In conclusion, nCounter gene expression assay seems to be a promising tool to study the expression of cytokine genes and thus could be used for the pre-clinical evaluation of novel analgesics.

Randomized control trial assessing the efficacy of pain control strategies for caustic paste disbudding in dairy calves younger than 9 days of age

Disbudding is a common procedure practiced in the dairy industry and is known to cause pain when performed without pain control. Dairy producers who disbud calves with caustic paste are less likely to provide pain control than those using cautery. Little research has been conducted on pain control for caustic paste disbudding and no studies have specifically examined calves under 9 d of age. The objective of this study was to evaluate the efficacy of local anesthesia and nonsteroidal anti-inflammatory drug analgesia on indicators of pain and inflammation in dairy calves disbudded using caustic paste. One hundred forty Holstein heifer calves 1 to 9 d of age were enrolled in 28 blocks and randomly allocated to 1 of 5 treatments: sham control (SH); positive control (POS); lidocaine cornual nerve block (LC); meloxicam (MEL); and lidocaine cornual nerve block plus meloxicam (LCM). We measured outcomes including serum cortisol and haptoglobin, pressure sensitivity, and lying behavior. Data were analyzed using mixed linear regression models with treatment as a fixed effect, baseline values as a covariate, and trial block as a random effect. Compared with the POS group, the LCM group had reduced serum cortisol at 15, 30, 45, and 60 min post-disbudding; cortisol values were not different between LC, LCM, and SH calves at these time points. At 60, 90, 120, and 180 min post-disbudding, LCM calves had reduced cortisol compared with LC calves, whereas, values did not differ between LCM and SH calves at these time points. At 3 to 4 d post-disbudding, the LCM group tended to have reduced haptoglobin, but no differences were found between groups at 180 min and 7 d post-disbudding. At 60, 90, and 120 min post-disbudding, LC and LCM treated calves had decreased pressure sensitivity compared with other groups. No differences were seen in pressure sensitivity between groups at 180 min, 3 to 4 or 7 d post-disbudding. No differences in lying behavior were found between treatment groups on any of the 7 d following disbudding. These findings demonstrate that the combination of a local anesthetic with a nonsteroidal anti-inflammatory drug is beneficial for reducing indicators of pain and inflammation in young calves disbudded with caustic paste.

Can Isoflurane and Meloxicam Mitigate Pain Associated with Cautery Disbudding of 3-Week-Old Goat Kids?

Simple Summary

Cautery disbudding is commonly carried out on goat kids less than a week of age to prevent horn growth; however, due to differences in management across farms, older goat kids (up to 3 weeks of age) can be disbudded. We evaluated the effect of pain mitigation strategies (isoflurane and meloxicam) on the behaviour and physiology of 3-week-old cautery-disbudded goat kids. We found weak statistical evidence that cortisol concentrations were lower in goat kids that were administered isoflurane (with or without meloxicam) compared to those disbudded without pain relief. However, no other physiological or behavioural measures were affected by the pain mitigation treatments. Further research is needed to determine whether isoflurane (with or without meloxicam) provides sufficient pain relief for disbudding 3-week-old goat kids.

Abstract

We evaluated the effect of pain mitigation strategies (isoflurane and meloxicam) on the behaviour and physiology of 3-week-old disbudded goat kids. Fifty Saanen does (mean ± SD, 21 ± 3 days old) were randomly allocated to one of five treatments: (1) cautery-disbudded (CAUT), (2) CAUT + isoflurane (ISO), (3) CAUT + isoflurane + meloxicam (ISO + MEL), (4) CAUT + meloxicam (MEL), and (5) handled without disbudding or pain relief (SHAM). Blood samples were taken immediately prior to treatment and at 15-, 60- and 120-min post-treatment to assess cortisol, glucose and lactate concentrations. Behaviour (head shaking and scratching, body shaking, feeding and self-grooming) was observed for 1 h pre- and post-treatment using video-cameras. ISO + MEL and ISO kids had lower cortisol concentrations than CAUT kids 15 min post-treatment (p ≤ 0.05). There was no effect of treatment or time for glucose and lactate concentrations (p ≥ 0.62). At 35 min post-treatment, CAUT, MEL and ISO kids performed more head shakes than SHAM kids (p ≤ 0.05). Isoflurane, with or without meloxicam, may reduce acute stress associated with disbudding of 3-week-old goat kids. More research is needed to assess whether isoflurane (with or without meloxicam) can provide sufficient pain relief for disbudding 3-week-old kids.

The Effect of Topical Anaesthesia on the Cortisol Responses of Calves Undergoing Dehorning

Simple Summary

Dehorning in cattle involves the manual removal of horns which causes acute pain. Although the long-term solution to removing horns is to breed polled cattle, limitations include the complex inheritance for polled Brahman cattle, and negative interactions with productivity in dairy cattle. Best practice pain relief in the form of a local nerve block, a sedative and a non-steroidal anti-inflammatory drug prior to the procedure usually requires a veterinarian and may be impractical for some cattle production systems. Improved livestock welfare requires a practical and cost-effective pain relief strategy for dehorning that can be readily adopted commercially. We evaluated a modified topical local anaesthetic wound formulation that can be applied by farmers immediately following dehorning. While previous studies have demonstrated a reduction in wound sensitivity, there was no effect on cortisol concentrations. It is likely that the cortisol response reflects a combination of factors including the stress of handling, the initial pain of the dehorning procedure and haemorrhage.

Abstract

Dehorning causes pain and distress to cattle, and there is a need to provide effective and practical analgesia to improve animal welfare. We conducted an experiment to determine the effect of a modified post-operative topical wound management formulation containing two local anaesthetics (TA) on the plasma cortisol concentration (PCC) of scoop-dehorned calves. Two months old Holstein-Friesian heifer calves (n = 30) were randomly allocated to sham dehorning control (CON), scoop dehorning (D), or scoop dehorning with immediate post-operative application of the TA (DTA). Blood samples were obtained via jugular venepuncture prior to sham or actual dehorning, and 40 min, 1.5, 4 and 24 h later. PCC changed significantly over time (p < 0.01). There was a trend for lower PCC in DTA calves compared to D calves (p = 0.09), with the PCC area under the curve lowest in CON calves as compared to D and DTA calves (p = 0.02). Cortisol concentrations were similar between D and DTA at all time points. The TA did not reduce cortisol concentrations up to 24 h following treatment and the cortisol response likely reflects the pain induced by the procedure, the effect of handling and restraint, and haemorrhaging which limited adherence of the TA actives. A multimodal analgesic approach, as assessed through multiple pain indicators, should be the focus of future work.

Evaluation of Pain Mitigation Strategies in Goat Kids after Cautery Disbudding

Simple Summary

Disbudding is a routine procedure performed in goat kids at an early age, especially the ones in the dairy industry. The procedure is mainly done to increase safety for other animals and workers in intensive dairy farms. Disbudding is a painful procedure that affects the welfare of the kids. Effective and practical pain mitigation strategies to reduce the suffering of goat kids due to disbudding have not yet been found. We studied two different pain mitigation strategies for this procedure and concluded that they were not entirely effective. Consumers are increasingly aware of animal farming practices, especially the ones that can lead to suffering and pain, such as disbudding. It is crucial that pain mitigation strategies as well as possible alternative solutions to disbudding continue to be investigated.

Abstract

Nowadays, most of the goat milk production in developed countries is done in intensive indoors production systems. In these systems, procedures such as disbudding are performed routinely. Disbudding is done in young goat kids and is a recognised as a painful procedure. Pain mitigation strategies have been extensively researched, but a method that is effective in mitigating pain as well as being safe and practical has not yet been found. In this paper we used three treatment groups: one control and two groups with pain mitigation strategies for cautery disbudding, one using local anaesthesia (lidocaine) and a second one using local anaesthesia (lidocaine) plus an analgesic (flunixin meglumine). The behaviour of twenty-seven goat kids was recorded for three hours after disbudding. Overall, the goat kids that received both pain mitigation treatments dedicated more time performing active and positive behaviours. Nevertheless, the incidence of behaviours related to pain and discomfort was not consistently reduced. Research is still needed to find a practical and effective pain mitigation strategy for disbudding. A solution to this challenge would improve animal welfare as well as address societal concerns linked to the suffering of farm animals.

Attitudes of cattle veterinarians and animal scientists to pain and painful procedures in Brazil

Recent studies have shown that cattle practitioners are concerned about painful conditions and procedures. An understanding of the attitudes toward pain is fundamental to encourage the use of pain relief in cattle. The goal of this study was to investigate the factors that influence Brazilian professionals toward the use of pain mitigation in cattle, primarily during castration and horn removal (e.g. dehorning, disbudding). To reach this objective, an online survey was conducted with veterinarians and animal scientists. The analysis was based on descriptive statistics, chi-squares tests, Fisher exact tests, and Mann-Whitney U tests. The final sample was composed of 147 respondents. Results of descriptive statistics showed that the use of medicine before a painful procedure (i.e., anesthetic, anti-inflammatory, or sedative-analgesic), was higher for adult cattle than for suckled and newborn calves. In newborn calves, those respondents who were more likely to use pain relief agreed with the statements that i) there is missing information about pain control during castration and ii) defensive movements shown by an animal during or after a procedure to justify pain mitigation in horn removal. The primary reasons for choosing a medicine were similar for both procedures: cost, anti-inflammatory effect, analgesic potency, duration of analgesic effect, duration of sedative effect, and route of administration. There was no difference in professional's decade of birth and pain mitigation use. These results may be useful to decide how to optimize the use of drugs by veterinary and animal science professions, and continuing education should help to increase pain mitigation usage.

Dehorning and welfare indicators in beef cattle: a meta-analysis

Dehorning is a common practice in cattle farming. Researchers suggest that pain during dehorning can be mitigated, although there is no conclusive evidence about the best technique and the best manner of pain relief. A systematic review-meta-analysis was performed to clarify the effect of dehorning on welfare indicators (cortisol concentration or average daily gain or vocalisation) in beef cattle up to 12 months of age. Five electronic databases were systematically searched, as well as conference proceedings and experts were contacted electronically. Pre-defined protocols were applied during all steps of the systematic review process. A random effect meta-analysis was conducted for each indicator separately with the mean of the control and treated groups. Four publications reporting seven studies and 69 trials were included in the MA involving 287 cattle. Heterogeneity between studies was observed for cortisol (I2 = 50.5%), average daily gain (I2 = 70.5%), and vocalisation (I2 = 91.9%). When comparing the non-dehorned group with amputation dehorning, the cortisol concentration was lower 30 min (P &lt; 0.0001) and 120 min (P = 0.023) after procedure (0.767 nmol/L and 0.680 nmol/L, respectively). Local anaesthesia did not show a reduction in cortisol concentration at 30 min after dehorning by amputation. Non-dehorned animals had a tendency to decrease the number of vocalisation (P = 0.081; MD = 0.929) compared with the group dehorned by amputation. These results suggest that dehorning is a painful experience and that local anaesthesia did not alleviate short-term pain following dehorning. Further investigation into pain relief is required to improve confident decision making under practical conditions.

Short communication: Evaluation of the efficacy of novel disbudding methods for dairy calves

The objectives of this study were to (1) evaluate whether cryoablation or the administration of clove oil was as efficacious as cautery disbudding at preventing horn growth, and (2) evaluate whether the efficacy of cautery disbudding is affected by removing or leaving the horn bud tissue intact after disbudding of dairy calves. At approximately 4 d of age (4.0 ± 0.88 d of age, mean ± SD), 265 dairy heifer calves from 3 dairy farms (farm 1: n = 129 calves; farm 2: n = 109 calves; farm 3: n = 27 calves) were disbudded. Each calf had 1 of 4 treatments randomly assigned to each horn bud: (1) clove oil (0.5 mL) administered subcutaneously under the horn bud (CLOV, n = 135 buds); (2) a liquid nitrogen-filled probe applied to the horn bud area for 30 s (CRYO, n = 134 buds); (3) cautery disbudding using an electric hot-iron and the horn bud removed (BUDOFF, n = 130); or (4) cautery disbudding and the horn bud tissue left intact (BUDON, n = 131). Calves were assessed for signs of infection at the disbudding site frequently within the first month after disbudding. At approximately 6 mo of age (6 ± 2.2 mo, mean ± SD) calves were assessed for scur or horn growth. The disbudding procedures were considered successful if no scur or horn development was observed. Within the first month, 12% of disbudding wounds showed some indication of infection, such as pus, exudate, or swelling; of the infected buds, 52% were associated with the BUDON treatment, 27% with CLOV, 25% with BUDOFF, and 2% with CRYO treatments. At 6 mo of age, BUDOFF was the most effective method of preventing horn growth and CRYO was the least efficacious [mean percentage of success: BUDOFF: 100% (95% CI: 97.7-100.0); CRYO: 1% (95% CI: 0.2-5.3)]. Injecting clove oil under the horn bud was 87% (95% CI: 80.6-92.5) successful. Not removing the horn bud tissue after cautery disbudding reduced the efficacy of this method by 9% [91% success (95% CI: 83.8-95.7)]; moreover, this method was associated with more infection at the site of disbudding. It appears as though the clove oil treatment could be used as an alternative to cautery disbudding of dairy calves; however, further research is needed to evaluate the tissue damage and associated pain caused by clove oil and to refine this technique (i.e., administration methods to improve efficacy) before it could be considered an alternative to cautery.

Postpartum ketoprofen treatment does not alter stress biomarkers in cows and calves experiencing assisted and unassisted parturition: a randomised controlled trial

Dystocia is considered painful and stressful for both the dam and the calf, although systematic evidence of this is limited. Few studies have investigated biochemical markers of stress and pain postpartum and whether any adverse effects are ameliorated by administration of analgesia. In this study, cow-calf pairs experiencing both mild to moderate farmer assistance and no assistance at parturition were randomly assigned to either treatment or placebo group in a two-by-two design (animals subject to veterinary intervention were excluded). The treatments were the NSAID ketoprofen or saline, administered within three hours of parturition. Blood samples taken in the immediate postpartum period, and at 24 hours, 48 hours and 7 days after parturition, were analysed for plasma concentrations of creatine kinase and cortisol (cows and calves) and plasma L-lactate and total protein concentration (calves). Stress biomarkers were highest in the immediate postpartum period and declined over time (P<0.05). Cow plasma cortisol was higher in animals experiencing assisted parturition in the immediate postpartum period (P=0.023); by 24 hours no difference was evident. Intervention with NSAID analgesia did not result in beneficial changes in stress biomarkers. Based on biomarkers alone, this suggests limited benefits of NSAID treatment in unassisted or mild to moderately assisted parturition.

Measurement of dairy calf behavior prior to onset of clinical disease and in response to disbudding using automated calf feeders and accelerometers

We determined if feeding and lying behavior, recorded by automatic calf feeding systems (ACFS) and accelerometers, could be used to detect changes in behavior before onset of neonatal calf diarrhea (NCD) or in response to disbudding pain in dairy calves. At 4 d of age, 112 calves had accelerometers attached to their hind leg and were housed in pens with ACFS. Calves were examined daily for signs of illness or injury. Of the 112 calves monitored, 18 were diagnosed with NCD; activities of calves with NCD were then compared with those of 18 healthy controls (calves that had no symptoms of NCD, other illnesses, or injury). Feeding (milk consumption and the number of rewarded and unrewarded visits to the feeder) and lying behavior during the 5 d leading up to calves displaying clinical signs of NCD were analyzed. Calves with NCD performed fewer unrewarded visits and consumed less milk than healthy calves during the 2- and 4-d periods before diagnosis with NCD, respectively. Calves with NCD tended to perform fewer lying bouts than healthy calves over the 5-d period before diagnosis with NCD. At 3 wk of age, a subset of 51 healthy calves were allocated to 1 of 5 treatment groups: (1) sham handling (SHAM, n = 10), (2) cautery disbudding (DB, n = 11), (3) administration of local anesthetic (LA) and DB (LA+DB, n = 11), 4) administration of a nonsteroidal anti-inflammatory drug (NSAID) and DB (NSAID+DB, n = 9), and (5) administration of LA, NSAID and DB (LA+NSAID+DB, n = 10). Feeding and lying behavior were recorded continuously for 24 h pre- and postdisbudding. We found no effect of treatment on the number of rewarded or unrewarded visits to the feeder and milk volume consumed 24 h before administration of treatments. During the 24-h postdisbudding period, SHAM calves performed more unrewarded visits than DB, LA+DB, and NSAID+DB calves, but the number of unrewarded visits did not differ between SHAM and LA+NSAID+DB calves. During the first hour of the posttreatment period we noted a difference in lying times among treatments, with DB and NSAID+DB calves spending less time lying than SHAM calves and lying times being similar between SHAM, LA+DB, and LA+NSAID+DB calves. The ACFS and accelerometers have the potential to automatically gather valuable information regarding health status and pain in calves. Therefore, it may be advantageous to combine both of these measures (ACFS and accelerometers) when evaluating NCD on farm or pain in calves in future research.

Evaluating treatments with topical anaesthetic and buccal meloxicam for pain and inflammation caused by amputation dehorning of calves

To assess the effects of a topical anaesthetic (TA) and buccal meloxicam (BM) on behaviour, maximum wound temperature and wound morphology following amputation dehorning of beef calves, 50 unweaned Hereford calves were randomly allocated to: (1) sham dehorning / control (CON, n = 14); (2) amputation dehorning (D, n = 12); (3) amputation dehorning with pre-operative buccal meloxicam (DBM, n = 12); and (4) amputation dehorning with post-operative topical anaesthetic (DTA, n = 12). Videos of the calves were captured for 3 h following treatment. Each calf was later observed for 5 min every hour and the frequency and duration of specific behaviours displayed during these focal periods was recorded. Infrared and digital photographs of dehorning wounds were collected from all dehorned calves on days 1, 3 and 7 following treatment. Infrared photographs were used to identify the maximum temperature within the wound area. Digital photographs were used to score wounds based on visual signs of inflammation and healing, using a numerical rating scale of 1 to 3, with morphological aspects of inflammation increasing and morphological aspects of healing decreasing with progressive scores. CON calves displayed fewer head shakes than all dehorned calves at 2 and 3 h following treatment (P = 0.025). CON and DTA calves displayed less head turns than DBM calves at 2 h following treatment (P = 0.036). CON calves displayed fewer combined point behaviours than all dehorned calves at 2 h following treatment (P = 0.037). All dehorning wounds had a greater maximum temperature on days 3 and 7 compared to day 1 (P = 0.003). All wound morphology scores decreased from day 1 to day 3 and wound morphology scores of DBM and DTA calves increased from day 3 to day 7 (P = 0.03). Although flystrike may have confounded these observations, no clear effects of TA or BM on behaviour, maximum wound temperature or wound morphology following dehorning of calves were observed. Further research is required to evaluate the analgesic efficacy of these products for amputation dehorning of calves.

Welfare Effects of the Use of a Combination of Local Anesthesia and NSAID for Disbudding Analgesia in Dairy Calves-Reviewed Across Different Welfare Concerns

Across the international dairy industry, the vast majority of dairy herds have dehorned cows. Farmers choose to dehorn calves for different reasons such as easier handling of non-horned cattle and reduced risk of injuries in animals and staff. This review focuses on disbudding by use of hot-iron cautery as is practiced by dairy farmers in calves <3 months of age. We examine welfare effects of the use of NSAIDs in combination with a local anesthetic including indicators relevant for the three major welfare concerns-affective states, basic health, and functioning as well as the possibility to behave naturally. Across indicators of animal welfare, the majority of available evidence suggest that the use of NSAIDs in combination with a local anesthetic is advantageous in terms of animal welfare, and no studies suggest that NSAIDs are a disadvantage to animal welfare. However, irrespective of the welfare concern, use of NSAIDs combined with a local anesthetic does not fully eliminate the welfare challenges from disbudding. Further research is needed in order to fully understand the effects of this medication protocol on calf welfare, including knowledge about the duration of healing and the presence of long-term pain. At present, this lack of knowledge challenges the precise formulation of adequate pain management-in terms of medication protocol, duration, dosage, and type of administration.

Evaluation of alternatives to cautery disbudding of dairy goat kids using physiological measures of immediate and longer-term pain

We evaluated alternatives to cautery disbudding of goat kids using physiological measures of immediate and longer-term pain. Fifty Saanen doe kids were randomly assigned to 1 of 5 treatments (n = 10/treatment): (1) cautery disbudding (CAUT), (2) caustic paste disbudding (CASP), (3) liquid nitrogen disbudding (CRYO), (4) clove oil injected into the horn bud (CLOV), or (5) sham disbudding (SHAM). Serum cortisol and haptoglobin concentrations were measured from blood samples collected immediately before treatment (baseline) and at 15, 30, 60, and 120 min and then again at 6 and 24 h post-treatment. An infrared thermography camera was used to take images of the horn buds 24 h pre- and 24, 48, and 72 h post-treatment to measure skin temperature. Body weight was measured daily for 1 wk to assess weight change post-treatment. Images of the horn buds were taken at d 1, 2, and 7 and at 6 wk post-treatment to assess tissue damage and wound healing. Mean cortisol concentrations were elevated in CASP kids 1 h post-treatment relative to CAUT kids. Cortisol concentrations of CRYO kids were higher than those of CAUT kids 30 min post-treatment; concentrations for CLOV kids were similar to CAUT kids post-treatment. Mean haptoglobin concentrations were similar across treatments over time; however, CLOV kids had higher concentrations at 24 h post-treatment than all other treatments. Skin temperatures of CASP and CLOV kids were elevated relative to CAUT kids at all time points post-treatment, and all disbudded kids had skin temperatures above those of SHAM kids at 72 h post-treatment. Treatment did not influence weight gain. The CAUT kids had large, open wounds exposing bone; small scabs were still evident 6 wk post-treatment. The CASP kids had red and open, raw wounds that generated large eschars, apparent for up to 6 wk. The CRYO kids had closed, dry wounds initially, but over time lesions appeared that caused open wounds; small scabs were present 6 wk post-treatment. The CLOV kids had closed, dry wounds with blackened skin; healed skin and minimal scabs were present 6 wk post-treatment. Caustic paste and cryosurgical disbudding appeared to cause more pain compared with cautery disbudding; thus, these methods may not provide good alternatives to cautery disbudding. Clove oil appeared to cause a similar pain response as cautery disbudding and smaller wounds with earlier tissue repair; this method shows promise as an alternative to cautery disbudding.

Assessing and mitigating post-operative castration pain in Bos indicus cattle

Cattle on pastoral land are subject to potentially painful husbandry procedures. In northern Australia, these practices generally occur once a year after the muster and the procedures are usually performed on animals older than 6 months of age. It is seldom that any pain mitigating medications are administered at this time and there is increasing concern that this perceived impost on the animal’s welfare will become more significant at both an economic and cultural level. There is a need to investigate the possibility of using simple, cost-effective, readily available medications, administered using relatively quick and easily taught techniques to increase the chance of industry adoption. This research used castration of 6–8-month-old Bos indicus calves as the test model because it is arguably one of the most common and most painful procedures endured by the animals. Forty-eight, 6–8-month-old Brahman bulls were surgically castrated after random assignment to six different treatment groups (n = 8): no castration Control (NC); castration (C); castration with post-operative meloxicam (CMpost-op); castration with lignocaine (CL); castration with lignocaine and post-operative meloxicam (CLMpost-op); castration with pre-operative meloxicam (CMpre-op). Serial measures of weight, blood cortisol concentrations, balk score, crush score, and daily activity (steps taken, number and duration of rest bouts) were taken. Linear mixed modelling was used to compare experimental groups. Bulls that were castrated and did not receive post-operative meloxicam (C and CL) had significantly lower average weights at all time points (Days 0–13, P < 0.001) of 170.9 kg and 168.6 kg, respectively, than those that did (CMpost-op and CLMpost-op) at 174.7 kg and 173.7 kg, respectively. When lignocaine was not administered before castration, Day 1 post-operative cortisol concentrations were significantly lower when post-operative meloxicam was provided than when it was not (CMpost-op: 47.2 nmol/L vs C: 65.5 nmol/L). When post-operative meloxicam was not given, animals that were given lignocaine before castration had significantly lower cortisol concentrations than those that received no lignocaine (CL: 52.7 nmol/L vs C: 65.5 nmol/L). Animals that were given pre-operative meloxicam had, on average, significantly lower Day 1 post-operative cortisol concentrations than animals that received no lignocaine or meloxicam (CMpre-op: 44.8 nmol/L vs C: 65.5 nmol/L). Analysis of Day 1 (the day following castration) data showed that animals that were given pre-operative meloxicam (CMpre-op) were significantly more active than animals in all other treatment groups (P = 0.038). It was concluded that 6–8-month old, Bos indicus bulls benefit from the administration of both lignocaine before surgery and peri-operative meloxicam. The analgesic methods used are readily adoptable by industry with respect to cost, efficiency and degree of technical skill required.

Evaluation of horn bud wound healing following cautery disbudding of preweaned dairy calves treated with aluminum-based aerosol bandage

Pain management during and following disbudding procedures has been studied extensively, though few studies have evaluated wound healing following cautery disbudding in dairy calves. The purpose of this study was to observe wound healing following cautery disbudding with or without treatment using a topical aluminum-based aerosol bandage (ALU) in preweaned dairy calves. Dairy calves were disbudded within the first 3 wk of life using a standard cautery disbudding protocol. The ALU treatment was randomly allocated to the right or left horn bud within each animal. The outcomes measured were lesion score (LS) and wound diameter (WD). The LS was evaluated on a scale of 1 to 3, with LS = 1 representing normal healing without a scab or exudate, LS = 2 having the presence of a scab, and LS = 3 showing the presence of wound exudate. Lesion score and WD were evaluated on a weekly basis following dehorning for 3 wk. A total of 209 animals completed the study. No difference was observed in LS between groups during the first 2 wk postdisbudding, but the proportion of LS = 3 on wk 3 postdisbudding was greater for the control group when compared with ALU (17 vs. 8%, respectively). During wk 1 and 2 postdisbudding, the odds of having delayed healing, or a LS ≥2, were similar for both groups. However, the odds tended to be different at wk 3 postdisbudding with control disbudding sites being 1.42 times more likely to have delayed healing than ALU. In wk 3, WD was 1 mm smaller in the treatment group compared with the control, and treatment decreased diameter over time compared with controls. Overall, once abnormal wound healing was observed, the likelihood of having abnormal wound healing the following week was increased. However, treatment with ALU diminished this effect on delayed healing during the follow-up period. Based on these results, the use of ALU improved wound healing following cautery disbudding of preweaned dairy calves.

Impact of carprofen administration on stress and nociception responses of calves to cautery dehorning

The objective of this study was to investigate the effects of carprofen administered immediately before cautery dehorning on nociception and stress. Forty Holstein calves aged approximately 6 to 8 wk old were either placebo treated and sham dehorned ( = 10) or cautery dehorned following administration of carprofen (1.4 mg/kg) subcutaneously ( = 10) or orally ( = 10) or a subcutaneous and oral placebo ( = 10) in a randomized, controlled trial. All animals were given a cornual nerve block using lidocaine before dehorning. Response variables including mechanical nociception threshold, ocular temperature, heart rate, and respiratory rate were measured before and following cautery dehorning for 96 h. Blood samples were also collected over 96 h following dehorning and analyzed for plasma cortisol and substance P concentrations by RIA. Plasma carprofen concentration and ex vivo PGE concentrations were also determined for this time period. Average daily gain was calculated for 7 d after dehorning. Data were analyzed using a linear mixed effects model with repeated measures, controlling for baseline values by their inclusion as a covariate in addition to planned contrasts. Dehorning was associated with decreased nociception thresholds throughout the study and a stress response immediately after dehorning, following the loss of local anesthesia, and 48 h after dehorning compared with sham-dehorned calves. Carprofen was well absorbed after administration and reached concentrations that inhibited ex vivo PGE concentrations for 72 h (subcutaneous) and 96 h (oral) compared with placebo-treated calves ( < 0.05). Carprofen-treated calves tended to be less sensitive ( = 0.097) to nociceptive threshold tests. Overall, at the dosing regimen studied, the effect of carprofen on sensitivity and stress following cautery dehorning was minimal. Consideration of route of administration and dose determination studies may be warranted.

Evaluating the efficacy of a topical anaesthetic formulation and ketoprofen, alone and in combination, on the pain sensitivity of dehorning wounds in Holstein-Friesian calves

The aim of this study was to investigate the effect of a topically applied local anaesthetic and the non-steroidal anti-inflammatory drug ketoprofen, alone and in combination, on the pain sensitivity response of calves to dehorning (mean age 2.2 months). Calves were randomly allocated and blocked by age to one of four groups. Groups were: scoop dehorning (D, n = 8), scoop dehorning + i.m. administration of 3 mg/kg ketoprofen (DK, n = 8), scoop dehorning + application of topical anaesthetic (DTA, n = 7) and scoop dehorning + application of topical anaesthetic and i.m. administration of ketoprofen (DKTA, n = 7). A pressure algometer was used to determine the mechanical nociceptive threshold (MNT), being the pressure (kg/f) at which calves withdrew from the stimulus. Measurements were taken before dehorning and at 1 min, 1, 2, 5 and 24 h post-dehorning at both the cut skin edge of the wound and the peri-wound area. The effect of treatment changed over time (P < 0.001). MNT was highest before treatment (MNT = 5.03 kg/f) and tended to decrease over time (MNT = 1.16 kg/f 24 h post-treatment). Overall, D calves exhibited the lowest MNT with an average of 1.77 kg/f. DTA calves had the highest MNT (3.89 kg/f), followed closely by DKTA calves (3.24 kg/f). DK calves exhibited an intermediate MNT of 2.61 kg/f. MNT of the cut skin edge was generally lower than that of the peri-wound area (2.01 vs 3.81 kg/f, respectively, P = 0.02).The topical anaesthetic formulation significantly reduced the pain sensitivity of dehorning wounds. There was no observed enhanced analgesic effect with addition of ketoprofen. The cut skin edge was more sensitive to pressure than the peri-wound area.

The effects of firocoxib on cautery disbudding pain and stress responses in preweaned dairy calves

Perioperative analgesic effects of oral firocoxib following cautery disbudding were investigated in preweaned calves. Twenty Holstein calves approximately 4 to 6wk old received a single oral dose of firocoxib, a nonsteroidal antiinflammatory, at 0.5mg/kg (n=10) or placebo (n=10) in a randomized controlled clinical trial. Responses, including ocular temperature determined by infrared thermography, pressure algometry measuring mechanical nociception threshold, and heart rate, were evaluated at 2, 4, 7, 8, and 24h after cornual nerve block and cautery disbudding. Blood samples were collected over 96h and analyzed for plasma cortisol and substance P concentrations by RIA. Additionally, ex vivo prostaglandin E2 concentrations were determined over a 72-h study period using an enzyme immunoassay. Data were analyzed using a linear mixed effects model with repeated measures. An inhibition of ex vivo prostaglandin E2 synthesis was observed from 12 to 48h following disbudding in calves treated with firocoxib. Cautery disbudding was associated with an increased nociception for the duration of sampling (24h). During the initial 24-h period following disbudding, no difference in response between treatment groups was noted. Following 24h, mean cortisol concentrations diverged between the 2 study groups with placebo-treated calves having increased cortisol concentrations at approximately 48h after disbudding. Furthermore, the overall integrated cortisol response as calculated as area under the effect curve tended to be reduced in firocoxib-treated calves. The prolonged effects of cautery dehorning require further investigation. Moreover, the effect of firocoxib on cortisol reduction observed in this study requires additional exploration.

Sublingual administration of detomidine to calves prior to disbudding: a comparison with the intravenous route

Objective

To study the effects of oromucosal detomidine gel administered sublingually to calves prior to disbudding, and to compare its efficacy with intravenously (IV) administered detomidine.

Study design

Randomised, prospective clinical study.

Animals

Twenty dairy calves aged 12.4 ± 4.4days (mean ± SD), weight 50.5 ± 9.0 kg.

Methods

Detomidine at 80 μg kg⁻¹ was administered to ten calves sublingually (GEL) and at 30 μg kg⁻¹ to ten control calves IV (V. jugularis). Meloxicam (0.5 mg kg⁻¹) and local anaesthetic (lidocaine 3 mg kg⁻¹) were administered before heat cauterization of horn buds. Heart rate (HR), body temperature and clinical sedation were monitored over 240 minutes. Blood was collected from the V. cephalica during the same period for drug concentration analysis. Pharmacokinetic variables were calculated from the plasma detomidine concentration-time data using non-compartmental methods. Statistical analyses compared routes of administration by Student's t-test and linear mixed models as relevant.

Results

The maximum plasma detomidine concentration after GEL was 2.1 ± 1.2 ng mL⁻¹ (mean ±SD) and the time of maximum concentration was 66.0 ± 36.9 minutes. The bioavailability of detomidine was approximately 34% with GEL. Similar sedation scores were reached in both groups after administration of detomidine, but maximal sedation was reached earlier in the IV group (10 minutes) than in the GEL group (40 minutes). HR was lower after IV than GEL from 5 to 10 minutes after administration. All animals were adequately sedated, and we were able to administer local anaesthetic without resistance to all of the calves before disbudding.

Conclusions and clinical relevance

Oromucosally administered detomidine is an effective sedative agent for calves prior to disbudding.

The effect of a topical anesthetic on the sensitivity of calf dehorning wounds

The objective was to determine the effect of a topical local anesthetic on the sensitivity of dehorning wounds in calves. Thirty 2-mo-old Holstein-Friesian calves were randomly allocated to sham dehorning control (CON), scoop dehorning without treatment with topical anesthetic (SnoTA), or scoop dehorning with an application of a topical anesthetic (STA). Sensitivity was measured by providing mechanical stimulation to the dehorned wound and peri-wound area using von Frey monofilaments calibrated at 10 and 300 g. Calf responses were categorized as absent, minor, moderate, or severe. Sensitivity measurements were performed before treatment and at various time points up to 24h posttreatment. Sham dehorned calves displayed unchanging absent or minor responses to stimulation. Regardless of whether topical anesthetic was applied, scoop dehorned calves were more likely to display minor, moderate, or severe responses than sham dehorned control calves, and responses tended to be most extreme at 4h postdehorning. Calves in the STA group tended to be less likely to display minor, moderate, or severe responses than calves in the SnoTA group at most time points (exception at 4h postdehorning). Responses were significantly more likely to be less severe in STA calves than in SnoTA calves at 40 min and 1.5h following dehorning. Thus, the use of the topical anesthetic for calves reduced the short-term sensitivity of scoop dehorning wounds.

Pain management with flunixin meglumine at dehorning of calves

Dehorning (DH) of calves is a common procedure on commercial dairy farms. Pain management of calves has been investigated in several studies. It is generally accepted that the use of local anesthesia before DH is essential for pain management. Postoperative inflammatory pain should be treated by using a nonsteroidal antiinflammatory drug. The objective of this controlled, randomized, and blinded clinical trial was to determine the effects of the nonsteroidal antiinflammatory drug flunixin meglumine before DH on cortisol concentrations in sera of 5- to 9-wk old calves. Furthermore, selected behavioral characteristics and heart and respiratory rate were examined to assess pain in the hours after dehorning. A total of 80 calves were allocated to 4 groups. In each of 20 replicates, 4 calves were randomly assigned to the following groups: in 3 treatment groups, calves received a local anesthetic (10 mL of procain hydrochloride) and a first treatment (i.v.) with flunixin meglumine or a placebo 20 min before hot-iron dehorning, and a second treatment with flunixin meglumine or a placebo (0.9% saline) 3 h after DH. Calves in the control (CON) group were not dehorned and did not receive any treatment. Groups received 2.2 mg of flunixin meglumine/kg followed by a placebo (FP), 2.2 mg of flunixin meglumine/kg for both treatments (FF), or a placebo for both treatments (PP). Blood samples were collected from all calves, including CON calves, 20 min before restraint in a headlock for DH, 2 min after DH, as well as 30 min and 1, 2, 4, 6, and 8 h after DH. Samples were analyzed for concentration of cortisol by enzyme immunoassay. It was found that concentration of cortisol, calculated as area under the curve, was greater in PP compared with FF and tended to be greater compared with FP. Significant differences between PP and FF were detected at 30 min and 2 h after DH. Throughout the observation period, cortisol concentrations were in both flunixin meglumine-treated groups at a similar level as in the CON group. The heart and respiratory rates showed neither difference between the CON group and the 3 dehorned groups nor between the treatment groups.

The effect of local or general anesthesia on the physiology and behavior of tail docked pigs

Tail docking of pigs is a routine procedure on farms to help control tail-biting behavior; however, docking can cause pain. The objective of this research was to evaluate the effect of local or general anesthesia on the physiology (experiment 1) and behavior (experiment 2) of tail docked pigs. Pigs were allocated to one of six treatment groups: (i) sham docking (CON); (ii) docking using conventional cutting (CUT) with side-cutting pliers; (iii) CUT docking plus local anesthesia injected immediately before docking (LA); (iv) CUT docking plus short-acting local anesthesia applied topically to the tail wound (SHORT); (v) CUT docking plus long-acting anesthesia applied topically to the tail wound (LONG) and (vi) CUT docking while the pig was anesthetized with carbon dioxide gas (CO(2)). In experiment 1, blood samples were collected from pigs (10 pigs per treatment) before and 30, 60 and 120 min after docking to measure leukocyte counts and percentages and cortisol concentrations. In experiment 2, the above treatments were repeated (10 pigs per treatment); the percentage of stress vocalizations were recorded during the administration of the treatments and behavior was recorded for up to 120 min after docking or handling. All pigs were weighed before and 24 h after docking and wound healing was recorded until weaning. The neutrophil/lymphocyte ratio was greater (P < 0.05) in CUT, LA, SHORT and LONG compared with CON pigs. At 30 min, cortisol concentrations were greater (P < 0.05) in CUT, LA, LONG and CO(2) compared with CON pigs. Cortisol concentrations did not differ (P > 0.05) between SHORT and CON pigs 30 min after docking. Cortisol concentrations did not differ (P > 0.05) among pigs given pain relief at the time of docking compared with pigs' docked without pain relief. Body weight change and wound scores did not differ (P > 0.05) among treatments. The percentage of stress vocalizations increased (P < 0.05) in CUT, SHORT and LONG, but not in CON, LA and CO(2) pigs in response to docking or handling. The percentage of time pigs spent lying without contact after docking tended to be greater (P = 0.06) in CUT pigs compared with all other docking treatments and CON pigs. In this study, none of the anesthesia treatments tested were effective at significantly changing the physiological or behavioral response to tail docking in pigs.

Scientific Opinion on the welfare of cattle kept for beef production and the welfare in intensive calf farming systems

Information given in previous Opinions "Welfare of cattle kept for beef production" (SCAHAW, 2001) and "The risks of poor welfare in intensive calf farming systems" (EFSA, 2006) is updated and recent scientific evidence on the topics reviewed. Risks of poor welfare are identified using a structured analysis, and issues not identified in the SCAHAW (2001) beef Opinion, especially effects of housing and management on enteric and respiratory diseases are reviewed. The Opinion covers all systems of beef production, although the welfare of suckler cows or breeding bulls is not considered. The Chapter on beef cattle presents new evidence and recommendations in relation to heat and cold stress, mutilations and pain management, digestive disorders linked to high concentrate feeds and respiratory disorders linked to overstocking, inadequate ventilation, mixing of animals and failure of early diagnosis and treatment. Major welfare problems in cattle kept for beef production, as identified by risk assessment, were respiratory diseases linked to overstocking, inadequate ventilation, mixing of animals and failure of early diagnosis and treatment, digestive disorders linked to intensive concentrate feeding, lack of physically effective fibre in the diet, and behavioural disorders linked to inadequate floor space, and co-mingling in the feedlot. Major hazards for white veal calves were considered to be iron-deficiency anaemia, a direct consequence of dietary iron restriction, enteric diseases linked to high intakes of liquid feed and inadequate intake of physically effective fibre, discomfort and behavioural disorders linked to inadequate floors and floor space.

Potential behavioural indicators of post-operative pain in male laboratory rabbits following abdominal surgery

This study aimed to identify behaviours that could be used to assess post-operative pain and analgesic efficacy in male rabbits. In consideration of the ‘Three Rs’, behavioural data were collected on seven male New Zealand White rabbits in an ethically approved experiment requiring abdominal implantation of a telemetric device for purposes other than behavioural assessment. Prior to surgery, rabbits were anaesthetised using an isoflurane/oxygen mix and given Carprofen (2 mg kg−1) as a peri-operative analgesic. Rabbits were housed individually in standard laboratory cages throughout. Data were collected at three time periods: 24-21 h prior to surgery (T1) and, post-surgery, 0-3 h (T2) and 3-6 h (T3). Behavioural changes were identified using Observer XT, significance of which was assessed using a Friedman's test for several related samples. The frequency or duration of numerous pre-operative behaviours was significantly reduced in T2 and T3, as compared to T1. Conversely, novel or rare behaviours had either first occurrence or significant increase in T2 into T3 as compared to T1, these include ‘full-body-flexing’, ‘tight-huddling’, ‘hind-leg-shuffling’. We conclude that reduced expression of common pre-operative behaviours and the appearance of certain novel post-operative behaviours may be indicative of pain in rabbits. Behaviours identified as increased in T2 as compared to T1 but not consistently elevated into T3 were considered separately due to the potentially confounding effect of anaesthesia recovery. These included lateral lying, ‘drawing-back’, ‘staggering’ and ‘closed eyes’. We postulate that for effective application of best-practice post-operative care, informed behavioural observation can provide routes by which carers may identify requirements for additional post-operative analgesia. Additionally, improvement of the peri-operative pain management regimen may be required to ameliorate the immediate effects of abdominal surgery. Comparisons with other studies into post-operative pain expression in rabbits suggest behavioural indicators of pain may differ, depending on housing and surgical procedure.

Chemical analgesia for velvet antler removal in deer

There is a legal requirement to provide analgesia for velvet antler removal in New Zealand. Currently, this is achieved using local anaesthetic blockade, with or without systemically administered sedative/analgesic agents, or by compression in 1-year-old stags. Lignocaine hydrochloride 2% is most commonly used and is most effective when administered as a high-dose ring block. Combinations of various amino-amide local anaesthetic agents can achieve rapid onset and prolonged duration of analgesia, though concerns about drug residues and carcinogenic potential of a lignocaine metabolite have led to consideration of the amino-ester family of local anaesthetics as alternatives. Systemically administered analgesics, including opioids, alpha-2-adrenergic agents and ketamine provide dose-dependent sedation and analgesia. However, none are sufficient, alone or in combination, to produce surgical analgesia at currently recommended dose rates and when reversal agents are given, analgesic effects are usually reversed as well as sedation. Thus, local anaesthetic blockade is still indicated, though the potential for drug or drug-metabolite residues in velvet antler remains a concern. The need for and effectiveness of non-steroidal anti-inflammatory drugs (NSAIDs) for post-operative analgesia requires investigation. Amitriptyline, locally administered opioid agonists, tramadol and other systemically administered agents may warrant future investigation for surgical and post-operative analgesia for velvet antler removal.

Acute castration and/or tailing distress and its alleviation in lambs

PURPOSES AND APPROACH: Acute castration and/or tailing distress in lambs has been examined extensively during the last decade. At least 59 different approaches to assessing and alleviating this distress have been reported so that the literature is quite complex. The purpose of this paper is to provide an overview of the literature on castration and/or tailing distress, where the distress was assessed using acute changes in plasma cortisol concentrations. A method of analysis involving the integrated cortisol response (i.e. the areas under the cortisol curves while the plasma concentration is above pretreatment values) to each treatment and using treatments which were common to different studies as reference points, allowed meaningful comparison within and between studies. A 6-point ranking scale emerged, where rank 1 represented the least distress and rank 6 the most distress.

COMPARISON OF ACUTE DISTRESS RESPONSES

This analysis revealed the following major points. Surgical methods of castration and/or tailing cause the greatest cortisol responses (rank 5 or 6). Most ring and ring plus clamp methods of castration plus tailing or castration, used without a local anaesthetic or systemic analgesic, cause rank 4 responses. One form of ring plus clamp castration (i.e. applying the clamp for 10 s across the full width of the scrotum distal to the ring in lambs aged no more than 1 week) reduces the cortisol response to rank 1. When these lambs are also tailed by applying a ring and clamp in a similar manner to the tail, they also exhibit a rank 1 response. Local anaesthetic given 10-20 or 12 min or 10-15 s before or immediately after ring only castration and/or tailing can virtually abolish the cortisol response (rank 1), depending on the site(s) of injection. For ring or ring plus clamp castration, the most effective sites (as judged by cortisol responses) are the neck of the scrotum or the testes. Delivery of local anaesthetic to achieve successful nerve blockade can be by needle, high-pressure needleless administration or, for the tail only, by an aerosol spray. Local anaesthetic injected into the scrotal neck, spermatic cords and/or testes has little effect on the overall cortisol response to clamp castration. Reductions in cortisol responses to clamp castration or to ring tailing can occur after administration of non-steroidal anti-inflammatory drugs. Most tailing methods elicit cortisol responses that are several ranks lower than those caused by castration plus tailing or castration alone. Although tailing by most methods elicits rank 1 cortisol responses, the use of local anaesthetic or non-steroidal anti-inflammatory drugs can reduce the response within the rank 1 range.

RECOMMENDATION

Farmers should be encouraged to choose the lowest ranked method that is economically and practically feasible for them. Specific methods such as surgical castration should be discouraged.

The effect of meloxicam on behavior and pain sensitivity of dairy calves following cautery dehorning with a local anesthetic

Effects of a single injection of meloxicam on calf behavior, pain sensitivity, and feed and water intakes were examined following dehorning. Sixty Holstein heifer calves were blocked by age and randomly assigned to receive an i.m. injection of meloxicam (0.5 mg/kg) or a placebo. All calves were given a lidocaine cornual nerve block (5 mL per horn). Treatments and nerve blocks were administered 10 min before cautery dehorning. Continuous sampling of behavior was performed during five 1-h intervals using video recordings, and total daily activity was monitored using an accelerometer. A pain sensitivity test was administered with a pressure algometer, and feed and water intakes were recorded daily. Calves were sham-dehorned 24 h before actual dehorning to establish baseline values, and all variables were assessed at the same times following dehorning and sham dehorning for up to 48 h post-dehorning. Meloxicam-treated calves displayed less ear flicking during the 44 h following dehorning (increases of 4.29+/-1.10 and 1.31+/-0.66 ear flicks/h in the first 24 h, and increases of 3.27+/-0.89 and 0.55+/-0.50 ear flicks/h during the second 24 h, for control and meloxicam calves, respectively) and less head shaking during the first 9 h following dehorning (increase of 2.53+/-0.54 and 0.85+/-0.46 headshakes/h over baseline for control and meloxicam, respectively). Meloxicam-treated calves were less active than controls during the first 5 h following dehorning (activity 34.1+/-3.2 and 30.6+/-2.6 for control and meloxicam, respectively) and displayed less sensitivity to pressure algometry 4 h after dehorning (pressure tolerance of 1.62+/-0.13 kg of force and 2.13+/-0.15 kg of force for control and meloxicam calves, respectively). Changes in behavior suggest that meloxicam was effective for reducing post-surgical pain and distress associated with calf dehorning.