The history and future of the cornual nerve block for calf disbudding

Disbudding damages the germinal horn bud cells and prevents subsequent horn growth in young calves. Hot-iron cautery or caustic paste are the most common disbudding techniques and are unequivocally painful procedures. An important technique in controlling the acute pain experienced during disbudding is the cornual nerve block (CNB) that uses a local anesthetic agent and targets a branch of the trigeminal cranial nerve, the zygomaticotemporal nerve, as it travels along the temporal groove of the skull. Though CNB have been used since 1932, practitioners have reported variability in achieving full desensitization of the horn bud region since its inception. This failure may have led to the establishment of variations in the CNB technique, without consensus on a reliable and repeatable approach. Reasons for CNB failures may include technical errors by the practitioner, such as an injection into subcutaneous or deep muscle bodies; biologically important path variations in the zygomaticotemporal nerve and its cornual branches; and secondary innervation of the horn bud region, particularly the cornual branches of the infratrochlear nerve. Further investigation into documenting and understanding CNB failure and alternatives, such as regional perfusion, is warranted.

Pilot testing an ethanol cornual nerve block as a long-term analgesic for calf disbudding

Disbudding prevents horn growth in calves through thermal or chemical cauterization and causes damage that is painful for weeks following the procedure. Current pain management strategies are only effective from 1 to 2 h (local anesthetic) to 1 to 3 d (nonsteroidal anti-inflammatory drugs). A potential practical solution for addressing longer-term pain may be to administer ethanol as a cornual nerve block. When administered at a high concentration, ethanol damages the functionality of peripheral nerves, promoting localized long-lasting analgesia. It is also thought to be painful, thus ethanol may be combined with lidocaine, as a mixed solution or administered beforehand. We tested the use of an ethanol cornual nerve block for anesthesia around the horn bud in 2 pilot studies. We used different concentrations and amounts of ethanol (100% and 70%) in combination with different ratios of lidocaine in our attempt to identify an effective block. In pilot 1, 14 nondisbudded calves were administered 2 to 4 mL of 100% ethanol below the bony ridge on each side of the head to block the cornual nerve at 3 to 10 d of age (n = 28 horn buds) and observed for 5 wk. The duration of loss of sensation was evaluated using pinprick tests 10 min, 1, 3, and 7 d after the block, and then weekly thereafter until 35 d or full sensation had returned. Pinprick tests consisted of lightly pressing a needle in 10 evenly spaced locations around the base of the horn bud (0 responses = no sensation, 1-5 responses = partial sensation, 6-10 responses = full sensation). Pilot 2 looked at the 24 h after the injection and consisted of 9 nondisbudded calves (5 mL of 2:1, 70% ethanol and 2% lidocaine per horn bud) and 6 disbudded individuals (5 mL of 100% ethanol, 70% ethanol, or 2% lidocaine per horn bud). All treatments were administered at the calf level. Anesthesia was checked 10 min after the injection and 4 or 16 h later. In pilot 1, on the day of the ethanol injection (0 d), there was no sensation in 85% of horn buds. Sensation began to return as early as 1 d after blocking, with only 50%, 21%, and 3% of horn buds having no sensation at 1, 7, and 35 d, respectively. Partial sensation was present in 25%, 17%, and 10% of horn buds at these time points. In pilot 2, 27.8% of horn buds in the nondisbudded group had no sensation, whereas 33.3% had partial sensation 10 min after the injection. In the disbudded calves 10 min after the injection, 100% of horn buds from the 100% ethanol group had partial sensation and 100% of horn buds administered 70% ethanol had full sensation. Four or sixteen hours later, 100% of horn buds had full sensation. Together, in these pilot studies, ethanol provided inconsistent anesthesia when used for a cornual nerve block.

Online Learning versus Hands-On Learning of Basic Ocular Ultrasound Skills: A Randomized Controlled Non-Inferiority Trial

Background and objectives: Ocular ultrasound is a core application of point-of-care ultrasound (POCUS) to assist physicians in promptly identifying various ocular diseases at the bedside; however, hands-on POCUS training is challenging during a pandemic. Materials and Methods: A randomized controlled non-inferiority trial was conducted in an academic emergency department from October 2020 to April 2021. Thirty-two participants were randomly assigned to one of two groups. Group H (hands-on learning group) participated individually in a hands-on session with a standardized patient for 30 min, whereas Group O (online learning group) learned training materials and video clips for 20 min. They scanned four eyeballs of two standardized patients sequentially following the ocular POCUS scan protocol. Repeated POCUS scans were performed 2 weeks later to assess skill maintenance. Both groups completed the pre- and post-surveys and knowledge tests. Two emergency medicine faculty members blindly evaluated the data and assigned a score of 0−25. The primary endpoint was the initial total score of scan quality evaluated using non-inferiority analysis (generalized estimating equation). The secondary endpoints were total scores for scan quality after 2 weeks, scan time, and knowledge test scores. Results: The least squares means of the total scores were 21.7 (0.35) for Group O and 21.3 (0.25) for Group H, and the lower bound of the 95% confidence interval (CI) was greater than the non-inferiority margin of minus 2 (95% CI: −0.48−1.17). The second scan scores were not significantly different from those of the first scan. The groups did not differ in scanning time or knowledge test results; however, Group H showed higher subjective satisfaction with the training method (p < 0.001). Conclusion: This study showed that basic online ocular ultrasound education was not inferior to hands-on education, suggesting that it could be a useful educational approach in the pandemic era.

Comparison of lidocaine alone or in combination with a local nerve block of ethanol, bupivacaine liposome suspension, or oral meloxicam to extend analgesia after scoop dehorning in Holstein calves

The American Veterinary Medical Association recommends the use of practices that reduce or eliminate pain and discomfort associated with dehorning. Identification of an effective, long-acting local anesthetic that is practical for producers to implement and reduces pain from dehorning would benefit animal welfare. Thirty-two Holstein bulls and heifers were enrolled. The objective of this study was to compare the efficacy and duration of activity of bupivacaine liposome suspension (BUP; n = 8), ethanol (ETH; n = 8), or meloxicam (LID + MEL; n = 8) co-administered with lidocaine compared with lidocaine only (LID; n = 8), and to quantify their effect on pain biomarkers and behaviors after scoop dehorning with cauterization in approximately 20-wk-old calves. Outcome variables collected included infrared thermography (IRT), mechanical nociceptive threshold (MNT), visual analog scale (VAS) scoring, and blood sampling for serum cortisol and prostaglandin E₂ metabolites (PGEM). There was evidence of a sex effect for MNT, with bulls demonstrating a higher threshold (13.74 kgf) compared with heifers (12.12 kgf). There was a treatment by time interaction for cortisol concentrations (ng/mL). At 2 h, the BUP group had higher cortisol values (17.32 ng/mL) than the LID + MEL group (3.10 ng/mL). Heifers also had higher mean cortisol values (13.88 ng/mL) compared with bulls (6.96 ng/mL). There was a treatment by time interaction for PGEM concentration. Calves in the LID + MEL group had lower PGEM values at 4 and 8 h (10.23 and 9.12 pg/mL) than at -24, 0, and 0.5 h (20.38, 27.27, and 22.59 pg/mL, respectively). At 4 h, the LID + MEL group had lower PGEM concentrations (10.23 pg/mL) than the ETH group (27.08 pg/mL). At 8 h, the LID + MEL group had lower PGEM concentrations (9.12 pg/mL) than both the ETH and BUP groups (24.80 and 20.52 pg/mL). Thus, LID + MEL reduced cortisol and prostaglandin metabolite concentrations more effectively than ETH + LID or BUP + LID administered as a local infiltration and cornual block, respectively, before scoop dehorning followed by cauterization. The treatments administered in the present study did not seem to extend the duration of analgesia beyond the currently recommended multimodal approach, including local anesthesia and systemic analgesia such as lidocaine and meloxicam. Evidence from the current study suggests that sex influences pain biomarkers such as nociceptive threshold and cortisol concentration, with males having a higher nociceptive threshold and lower cortisol responses.

Dairy calves show behavioural responses to hot iron disbudding after local anaesthesia with procaine

BACKGROUND

The efficacy of procaine as anaesthetic for disbudding of calves is largely unknown. Likewise, information about effect of interval from local anaesthesia to disbudding and the size of the hot iron used is missing.

METHODS

A total of 167 dairy calves were disbudded after cornual nerve block with procaine. Time from administration of anaesthetic to disbudding varied, and calves were disbudded using two different sizes of hot iron. The calves' behavioural responses to disbudding were recorded based on (1) getting up, (2) kicking, and (3) lifting head. Using logistic regression, the associations between calves showing at least one of these three behaviours and interval from administration of anaesthetic to disbudding and size of the hot iron were evaluated.

RESULTS

Overall, 42% of calves showed at least one of the three behaviours, even though they had received a cornual nerve block prior to disbudding. Using the large hot iron was associated with a 2.3 times higher odds of the calf reacting behaviourally compared to the small iron. Interval from administration of anaesthetic to disbudding was not significantly associated with the odds of behavioural responses.

CONCLUSION

Approximately 40% of calves disbudded after cornual nerve block with procaine showed signs of inadequate local anaesthesia. This was especially problematic when hot irons with larger tips were used.

Health and Welfare Survey of 30 Dairy Goat Farms in the Midwestern United States

Simple Summary

There appears to be a rapid expansion of dairy goat farming in the United States and the information available to producers on health, welfare, and production applicable to those in the Midwestern US is limited. This study intended to survey 30 dairy goat farms in the Midwestern US to provide insight into husbandry practices pertaining to health, welfare, and production, and to identify areas of future research. Pain relief for disbudding and castration, education and training programs, early kid management, and hoof trimming were identified as potential areas of future research. This study provided insight into the husbandry practices carried out on 30 dairy goat farms in the Midwestern US and areas of research to improve health and welfare.

Abstract

Dairy goat production in the Midwestern United States is increasing at a rapid rate and information on dairy goat husbandry practices applicable for producers in this region is limited. The objective of this study was to survey 30 dairy goat farms in the Midwestern US to provide insight into husbandry practices pertaining to health, welfare, and production, and to identify areas of future research. A questionnaire was developed and comprised 163 questions that were organized into categories including information on the producer (e.g., farming experience), staff, and goats (e.g., herd size, breed), housing, feeding and nutrition, milking practices and production, kid management, husbandry practices (e.g., disbudding, castration, hoof trimming), and health. Areas of future research that can improve goat health, production and welfare include pain relief for husbandry practices such as disbudding and castration, early kid management during birth to prevent illness/disease or mortality (e.g., warm and dry areas for kid rearing), eradication programs for common contagious diseases, training programs and education for claw trimming, disbudding, and udder health. In conclusion, this study provided insight into the husbandry practices carried out on 30 dairy goat farms in the Midwestern US and areas of research to improve health and welfare.

Welfare Assessment of 30 Dairy Goat Farms in the Midwestern United States

Dairy goat animal welfare assessment protocols have been developed and conducted in Europe and the United Kingdom for dairy goats; however, there are no published reports of large-scale welfare assessment for dairy goats on farms in the Midwestern United States (US). Therefore, the objective of this study was to perform welfare assessment of lactating dairy goats and identify the most prevalent welfare issues on 30 farms across the Midwestern US. Thirty dairy goat farms (self-selected) were enrolled in the study if they shipped milk for human consumption (regardless of herd size). The number of lactating does on each farm ranged from 34 to 6,500 goats, with a median number of 158 lactating does (mean ± SD: 602 ± 1,708 lactating does). The protocol used was developed from available literature on goat welfare assessment but modified for use in the Midwestern US. Observations were made without handling the animals and included 22 animal-based indicators evaluated at the group- and individual-level. The observations were conducted during ~3-5 h during a milking session (either morning or afternoon) and time in the home pen. Principal components analysis (PCA) was carried out on the welfare assessment data from each farm. The first two dimensions of the PCA explained 34.8% of the variation. The PCA biplot indicated correlations between indicators. The most prevalent conditions observed across the 30 farms included any knee calluses (80.9%), any claw overgrowth (51.4%), poor hygiene (14.9%), skin lesions (8.9%), poor hair coat condition (8.3%) and any ear pathology (8.0%). These results are the first to provide the Midwestern US dairy goat industry with information to improve commercial dairy goat welfare.

My pigs are ok, why change? - animal welfare accounts of pig farmers

Intensive pig production systems are a source of stress, which is linked to reduced animal welfare and increased antimicrobial use. As the gatekeepers of the welfare of the animals under their care, farmers are seen as the stakeholder responsible for improving animal welfare. The aim of this study was to explore the knowledge and attitudes of pig farmers towards pig welfare and the impact of such attitudes on farmers' selection of management strategies on the farm. We conducted in-depth semi-structured interviews with 44 pig farmers in one of the main pig producing regions of Brazil. Interviews covered knowledge and attitudes towards pig sentience and behaviour and welfare-related issues commonly observed in intensive pig farms (belly-nosing, fights, tail-biting, diarrhoea and castration without pain control) and farmers' conception and attitudes towards pig welfare. We identified many management and animal-based indicators of poor welfare, such as the use of painful and stressful management practices and use of environments that limit the expression of natural behaviours. However, most farmers were satisfied with animal welfare standards at their farms. Farmers' perceptions are aligned with their understanding of animal welfare. Although they identified all the dimensions that impact the welfare of a pig on a farm (affect, biological functioning and naturalness), their social reality, industry demands and available advice pushed them to perceive their range of action limited to biological and environmental aspects of the animals that do not necessarily benefit affective state. This precluded farmers from making associations between good health and the animal's ability to express a full behavioural repertoire, as well as from viewing abnormal behaviours as problems. The negative consequences for the welfare of the animals were commonly alleviated by routines that relied on constant use of medication, including high dependence on antibiotics. Expressions of estrangement from the production chain were common voices among the participants. This suggests that farmers may not be sufficiently informed or engaged in responding to consumers' expectations and commitments made by companies, which can pose a severe economic risk for farmers. The findings of this study indicate that economic, technical and social factors restrict farmers' autonomy and their ability to perform their role as stewards of animal welfare. (Re)connecting different human, animal and environmental interests may be a step to changing this scenario.

The Educational Efficacy of Humane Teaching Methods: A Systematic Review of the Evidence

Humane alternatives to harmful educational animal use include ethically-sourced cadavers, models, mannequins, mechanical simulators, videos, computer and virtual reality simulations, and supervised clinical and surgical experiences. In many life and health sciences courses, however, traditional animal use persists, often due to uncertainty about the educational efficacy of humane alternatives. The most recent comprehensive reviews assessing learning outcomes of humane teaching methods, in comparison to harmful animal use, were published more than 10 years ago. Therefore, we aimed to collate and analyse the combined evidence from recent and older studies about the efficacy of humane teaching methods. Using specific search terms, we systematically searched the Web of Science, SCOPUS, and EMBASE databases for relevant educational studies. We extracted information on publication years, the country in which the study was conducted, field, humane teaching methods, form of learning outcome assessment, and the learning outcome of the humane teaching methods, in comparison with harmful animal use. We found 50 relevant studies published from 1968-2020, primarily stemming from the USA, UK, and Canada. Humane teaching methods produced learning outcomes superior (30%), equivalent (60%), or inferior (10%) to those produced by traditional harmful animal use. In conclusion, a wide-spread implementation of humane teaching methods would not only preserve learning outcomes, but may in fact be beneficial for animals, students, educators, and institutions.

Short communication: Microlearning courses are effective at increasing the feelings of confidence and accuracy in the work of dairy personnel

Optimization of work processes and personnel compliance becomes progressively essential to ensure high process and product quality on dairy farms with an increasingly nonfamily work force. Standard operating procedures (SOP) are important to minimize variation. In addition to having a set of protocols and SOP, regular training of employees is indispensable to reduce procedural drift. A total of 243 farm owners, employees, and veterinarians from 35 farms were invited to take 3 microlearning lessons for colostrum management and provide feedback in an embedded survey. The overall response rate was 48%, and almost all participants accessed the SOP within the course (i.e., 92, 90, and 96% in the first, second, and third course, respectively). Overall, 59% (22/37) launched the course in their leisure time and 80% stated that they were convinced to work more accurately after having taken the course. Most employees underestimated the time spent in the course (76%), accessed background information (89%), or provided feedback (55%). These observations are indicative of high engagement. Overall, 78% of employees felt more confident in correct task completion after the training.

A qualitative study of Ontario dairy farmer attitudes and perceptions toward implementing recommended milking practices

Recommended milking practices (RMP) are protective against mastitis. However, many producers do not adopt, or only partially adopt, these measures. This study aimed to explore the attitudes and perceptions of Ontario dairy farmers toward barriers to implementation of RMP and to investigate what motivates behavior change in relation to milking hygiene. Four focus groups with Ontario dairy producers were conducted, and verbatim transcripts were analyzed thematically. The main barriers to adoption of RMP were identified and categorized into 2 groups: intrinsic barriers and physical barriers. Intrinsic barriers included personal habits and convenience, not perceiving udder health as a priority on their farm, and lack of information. Physical barriers included employee training and compliance, convenience of implementing RMP, and time, money, and labor barriers. Producers used their bulk tank somatic cell count (SCC) as a measure of perceived severity of udder health problems on farm. Those with lower SCC were less likely to prioritize udder health compared with peers experiencing elevations in SCC. Lack of udder health problems translated for some producers into non-adoption of certain RMP, as they felt these practices were not needed unless a problem arose. Others felt motivated to implement more practices and work toward better udder health if such efforts translated into rewards for better-quality milk. Some producers perceived RMP as not meaningful or useful, seemingly due to a lack of education about the reasons behind RMP implementation. Understanding the importance of these practices is one key to implementing them. To overcome some of the intrinsic barriers, increased efforts in knowledge translation are needed, including efforts in retraining current practices, as well as in establishing best practices.

A new method of administering local anesthesia for calf disbudding: Findings from a comparative on-farm study in New Zealand

Anesthesia of the horn bud for calf disbudding commonly is attained by injection of local anesthetic over branches of the cornual nerve, with anesthesia achieved in 3 to 20 min. With experienced and trained staff, this method is effective in 88 to 100% of calves. Variability in response and time of onset can compromise calf welfare if calves are disbudded before anesthesia is attained. Proposed legislative reliance on effective local anesthetic as the minimal method of pain relief for calves at disbudding means that administration of local anesthetic must achieve a repeatable level and rapid onset of analgesia. We describe an alternative method of local anesthesia administration that uses local site infiltration of anesthetic over the horn bud. However, this method has not yet been scientifically validated. This study assessed differences between disbudding using the cornual nerve block and disbudding with local anesthesia administered by local site infiltration. Efficacy of local anesthesia was assessed at 30-s intervals after administration by absence of reaction to 3 consecutive needle pricks over the horn buds. Behavior indicating pain was assessed during disbudding and scored from 0 to 3. Calf behavior was also recorded for 3 h after disbudding. Accelerometer data loggers were fitted to each calf for 24 h before and after disbudding to assess lying and standing times. Median time to cutaneous desensitization for local infiltration was 60 s compared with 225 s for cornual nerve block, and the variance in time to desensitization was less with local infiltration. Calves disbudded under cornual block had a larger behavioral response (indicated by a graded aversive body reaction) than calves disbudded under local infiltration. A multivariable model predicted that the mean body reaction score would be 0.6 for calves disbudded under local infiltration and 1.2 for calves disbudded under cornual block. There was no difference in any behaviors between the treatment groups in the 3 h after disbudding. Method of analgesia had no effect on lying time over the 24 h after disbudding. In this study, local infiltration was at least as effective in providing analgesia for disbudding as the cornual nerve block. Our results suggest that a more consistent, effective level of analgesia during disbudding was achieved using local infiltration and that there was no difference in postoperative expressions of pain.