The morphology of the interfacial tissue between bighorn sheep horn and bony horncore increases contact surface to enhance strength and facilitate load transfer from the horn to the horncore.

The horns of bighorn sheep rams are permanent cranial appendages used for high energy head-to-head impacts during interspecific combat. The horns attach to the underlying bony horncore by a layer of interfacial tissue that facilitates load transfer between the impacted horn and underlying horncore, which has been shown to absorb substantial energy during head impact. However, the morphology and mechanical properties of the interfacial tissue were previously unknown. Histomorphometry was used to quantify the interfacial tissue composition and morphology and lap-shear testing was used to quantify its mechanical properties. Histological analyses revealed the interfacial tissue is a complex network of collagen and keratin fibers, with collagen being the most abundant protein. Sharpey's fibers provide strong attachment between the interfacial tissue and horncore bone. The inner horn surface displayed microscopic porosity and branching digitations which increased the contact surface with the interfacial tissue by approximately 3-fold. Horn-horncore samples tested by lap-shear loading failed primarily at the horn surface, and the interfacial tissue displayed non-linear strain hardening behavior similar to other soft tissues. The elastic properties of the interfacial tissue (i.e., low- and high-strain shear moduli) were comparable to previously measured values for the equine laminar junction. The interfacial tissue contact surface was positively correlated with the interfacial tissue shear strength (1.23 ± 0.21 MPa), high-strain shear modulus (4.5 ± 0.7 MPa), and strain energy density (0.38 ± 0.07 MJ/m3). STATEMENT OF SIGNIFICANCE: The bony horncore in bighorn sheep rams absorbs energy to reduce brain cavity accelerations and mitigate brain injury during head butting. The interfacial zone between the horn and horncore transfers energy from the impacted horn to the energy absorbing horncore but has been largely neglected in previous models of bighorn sheep ramming since interfacial tissue properties were previously unknown. This study quantified the morphology and mechanical properties of the horn-horncore interfacial tissue to better understand structure-property relationships that contribute to energy transfer during ramming. Results from this study will improve models of bighorn sheep ramming used to study mechanisms of brain injury mitigation and may inspire novel materials and structures for brain injury prevention in humans.

Economic considerations of breeding for polledness versus disbudding in beef cattle.

The domestication of animals has rendered horns less necessary for survival. Moreover, the use of polled and disbudded animals is interesting in order to avoid injuries of animals and handlers, among other advantages. We therefore conducted a comparative economic analysis of different traditional disbudding techniques versus selective breeding for polledness in Nelore cattle, the main beef breed of tropical systems in Brazil. The cost to obtain animals without horns was estimated in three different scenarios: disbudding with hot iron, disbudding with caustic paste, and phenotypic selection for polled animals. Price quotations of the materials were obtained in different states of the country and averaged. An initial frequency of horned animals of 92.16% was obtained based on the records of the Brazilian Association of Zebu Breeders. Selective breeding was found to be the best cost-effective scenario. This result differs from intensive production systems of dairy cattle in which traditional disbudding continues to be the best cost-effective scenario. The main explanation is the lack of difference in the price of Nelore semen from polled and horned bulls. Phenotypic selection for polled animals is the best cost-effective method, and it is in accordance with welfare practices. Care should be taken regarding the intensive use of few polled breeding animals in order to avoid inbreeding depression in other traits.

The effects of pain following disbudding on calf memory.

Studies have found evidence of pain in the hours following hot-iron disbudding, but little is known about longer-lasting pain following this procedure. Work on humans and rats has shown that lasting pain can have negative effects on the formation and recall of memories. The objective of this study was to assess whether lasting pain following disbudding affects learning and memory in calves. A modified hole-board apparatus was used to assess how quickly calves were able to learn the locations of 4 bottles containing milk dispersed among 11 locations with empty bottles. At 14 d of age and after 6 d of training on this task, calves (n = 30) were randomly assigned to 3 treatments: disbudding with analgesic on the day of the procedure, disbudding with analgesic throughout the study, and sham disbudding. All calves were sedated, given a lidocaine cornual local block and a single injection of an nonsteroidal anti-inflammatory drugs. Starting on the day after their disbudding treatment, calves were tested daily using the modified hole-board apparatus. After 12 d of testing, the locations of the 4 milk-containing bottles were switched, and calves then relearned the locations of the rewarded bottles over the next 6 daily test sessions. We found general working memory (i.e., short-term memory) and reference memory (i.e., long-term memory) increased over the 12 d of testing, declined when locations were switched on d 13, and then again increased over the final 6 d of testing. We did not find an effect of treatment on any measure, perhaps because there was no lasting pain or because effects were too minor to detect using this test of spatial memory.

Evolution of horn length and lifting strength in the Japanese rhinoceros beetle Trypoxylus dichotomus.

What limits the size of nature's most extreme structures? For weapons like beetle horns, one possibility is a tradeoff associated with mechanical levers: as the output arm of the lever system-the beetle horn-gets longer, it also gets weaker. This "paradox of the weakening combatant" could offset reproductive advantages of additional increases in weapon size. However, in contemporary populations of most heavily weaponed species, males with the longest weapons also tend to be the strongest, presumably because selection drove the evolution of compensatory changes to these lever systems that ameliorated the force reductions of increased weapon size. Therefore, we test for biomechanical limits by reconstructing the stages of weapon evolution, exploring whether initial increases in weapon length first led to reductions in weapon force generation that were later ameliorated through the evolution of mechanisms of mechanical compensation. We describe phylogeographic relationships among populations of a rhinoceros beetle and show that the "pitchfork" shaped head horn likely increased in length independently in the northern and southern radiations of beetles. Both increases in horn length were associated with dramatic reductions to horn lifting strength-compelling evidence for the paradox of the weakening combatant-and these initial reductions to horn strength were later ameliorated in some populations through reductions to horn length or through increases in head height (the input arm for the horn lever system). Our results reveal an exciting geographic mosaic of weapon size, weapon force, and mechanical compensation, shedding light on larger questions pertaining to the evolution of extreme structures.

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.

Caustic paste disbudding (CPD) is a widely used practice in the cattle industry, yet there is a shortage of literature on the effects of meloxicam on calves aged 10 to 21 d who have undergone this procedure. In this clinical trial, we conducted a comparative analysis of the pain-related behavioral, physiological, and hematological performance of calves that were administered with either lidocaine plus normal saline (n = 15) or lidocaine plus meloxicam (n = 15) before undergoing disbudding operations. The findings demonstrated that the CPD operation had a significant impact on the pain-related behavior, physiological functions, and serum anti-inflammatory and antioxidative markers of the calves. On the other hand, the administration of meloxicam had notable advantages for the calves by enhancing the physiological and hematological parameters.

Behavioral changes in the first 3 weeks after disbudding in dairy calves.

Hot-iron disbudding, the practice of cauterizing horn bud tissue to prevent horn growth in dairy calves, results in behavioral changes indicative of pain in the first few days after the procedure. However, few studies have quantified behavioral changes in the following weeks, while the burn wounds are still healing. Female Holstein calves were disbudded with a heated iron and pain relief (5.5 mL lidocaine cornual nerve block and 1 mg/kg oral meloxicam) at 4 to 10 d of age (n = 19) or not disbudded (n = 19). Calves wore ear tag accelerometers that reported the dominant behavior being performed at 1-min intervals from 3 to 21 d after disbudding. Compared with age-matched controls, disbudded calves tended to spend more time inactive throughout the observation period, ruminated less in the first 3 to 11 d after disbudding, and sucked more from a milk bottle beginning 5 d after disbudding until the end of the 21-d observation period. In addition to the accelerometer data, live observations of sleeping (using a behavioral proxy), lying, and ruminating were collected using instantaneous sampling at 5-min intervals for 24-h periods 3, 10, and 17 d after disbudding. Disbudded calves slept with their head down more on all live observation days and spent more time lying on the 17th d after disbudding, but ruminating did not differ compared with controls, in contrast to the accelerometer results. More time spent inactive, sleeping, and lying, and less time spent ruminating (as indicated by the accelerometer) can be interpreted as attempts to reduce painful stimulation of the disbudding wounds and allocate energy to healing. It is unclear whether the greater amount of sucking in the disbudded calves is nutritive (milk present) or non-nutritive (milk absent), as the algorithm did not distinguish the type of sucking, and further research is needed to explore the factors underlying this effect. We conclude that disbudding alters daily behavior patterns for at least 3 wk, far beyond the duration of recommended pain medication, raising additional welfare concerns about the procedure.

Wound healing and pain sensitivity following caustic paste disbudding in dairy calves.

Caustic paste disbudding is increasing in popularity on commercial dairy farms in the United States, but little research has explored the pain and welfare implications beyond the acute period of this procedure. In contrast, researchers have reported it takes 7 to 9 wk, on average, for hot-iron disbudding wounds to re-epithelialize in dairy calves. Our objective was to describe wound healing and sensitivity following caustic paste disbudding. Jersey and Holstein female calves were disbudded using caustic paste (H. W. Naylor Company Inc.) at 3 d of age (n = 18), and control calves received a sham procedure (n = 15). Before disbudding, calves received a local block and a nonsteroidal anti-inflammatory drug. Calves ≥34 kg and <34 kg at birth had 0.3 or 0.25 mL of paste applied per unshaved horn bud, respectively. Following disbudding, wounds were scored 2×/wk for the presence or absence of 8 tissue categories, including the final stages: new epithelium and fully healed. Control calves were removed from the experiment after 6 wk to be hot-iron disbudded. Mechanical nociceptive threshold (MNT) measures were collected weekly to evaluate wound sensitivity until calves were removed from the study or healed. Wounds were slow to re-epithelialize (16.2 ± 5.7 wk, mean ± SD; range: 6.2-32.5 wk) and contract to be considered fully healed (18.8 ± 6 wk, mean ± SD; range: 8.7-34.1 wk). Compared with non-disbudded controls, paste calves exhibited lower MNT values for all 6 wk (mean ± SE; control: 1.46 ± 0.16; paste: 1.18 ± 0.12 N). These data indicate that wounds from caustic paste disbudding are more sensitive than undamaged tissue for at least 6 wk and take twice as long to heal compared with cautery methods described in the literature. In conclusion, caustic paste disbudding wounds took 18.8 wk to fully heal and were more sensitive than intact horn buds for 6 wk. Future work should examine whether aspects of paste application (e.g., amount used, time rubbed in, calf age, pain mitigation) could improve healing time and sensitivity.

Calves peak-end memory of pain.

In humans, the 'peak-end' rule states that recollection of an experience is most often influenced by the peak (the most intense moment) and end of the experience. We investigated whether calves followed the peak-end rule in their memory of a painful procedure: disbudding. As proxies for retrospective and 'real-time' reports of pain, we used conditioned place aversion, and reflex pain behaviours. In two separate trials, calves were subjected to two disbudding conditioning sessions (one horn per treatment), acting as their own control. In the first trial, calves (n = 22) were disbudded and remained in a pen for 4 h, and disbudded and left in another pen for 4 h with an additional 2 h following an analgesic treatment. In the second trial, calves (n = 22) were disbudded and left in pens for 6 h during both treatments, receiving the analgesic at either 2 h or 4 h after disbudding. Calves were then tested for place aversion. For both trials we did not observe a preference for the pens where calves received analgesic treatment towards the end of the session. We did not find an association between aversion and the sum, peak or end of pain behaviours. Results are not consistent with a peak-end effect in calves' memory of pain.

Topologically associating domains in the POLLED region are the same for Angus- and Brahman-specific Hi-C reads from F1 hybrid fetal tissue.

Horns, a form of headgear carried by Bovidae, have ethical and economic implications for ruminant production species such as cattle and goats. Hornless (polled) individuals are preferred. In cattle, four genetic variants (Celtic, Friesian, Mongolian and Guarani) are associated with the polled phenotype, which are clustered in a 300-kb region on chromosome 1. As the variants are intergenic, the functional effect is unknown. The aim of this study was to determine if the POLLED variants affect chromatin structure or disrupt enhancers using publicly available data. Topologically associating domains (TADs) were analyzed using Angus- and Brahman-specific Hi-C reads from lung tissue of an Angus (Celtic allele) cross Brahman (horned) fetus. Predicted bovine enhancers and chromatin immunoprecipitation sequencing peaks for histone modifications associated with enhancers (H3K27ac and H3K4me1) were mapped to the POLLED region. TADs analyzed from Angus- and Brahman-specific Hi-C reads were the same, therefore, the Celtic variant does not appear to affect this level of chromatin structure. The Celtic variant is located in a different TAD from the Friesian, Mongolian, and Guarani variants. Predicted enhancers and histone modifications overlapped with the Guarani and Friesian variants but not the Celtic or Mongolian variants. This study provides insight into the mechanisms of the POLLED variants for disrupting horn development. These results should be validated using data produced from the horn bud region of horned and polled bovine fetuses.

Effects of multimodal pain management strategies on acute physiological and behavioral response to cautery disbudding in neonatal goat kids.

Dairy goat kids are commonly disbudded in the United States without pain relief. Our objective was to identify an efficient pain management strategy by monitoring changes in plasma biomarkers and behavior of disbudded goat kids. A total of 42 kids (5-18 d old at the time of disbudding) were randomly allocated to 1 of 7 treatments (n = 6/treatment): sham treatment; 0.05 mg/kg i.m. xylazine (X); 4 mg/kg subcutaneous buffered lidocaine (L); 1 mg/kg oral meloxicam (M); xylazine and lidocaine (XL); xylazine and meloxicam (XM); and xylazine, meloxicam, and lidocaine together (XML). Treatments were administered 20 min before disbudding. One trained individual, blinded to treatment, disbudded all kids; sham-treated kids were handled similarly except the iron was cold. Jugular blood samples (3 mL) were obtained before (-20, -10, and -1 min) and after (1, 15, and 30 min, and 1, 2, 4, 6, 12, 24, 36, 48 h) disbudding and analyzed for cortisol and prostaglandin E2 (PGE2). Mechanical nociceptive threshold (MNT) testing was performed at 4, 12, 24, and 48 h after disbudding, and kids were weighed daily until 2 d post-disbudding. Vocalizations, tail flicks, and struggle behavior during disbudding were recorded. Cameras were mounted over home pens; continuous and scan observations over 12 periods of 10 min each, in the 48 h after disbudding, captured frequency of locomotion and pain-specific behaviors. Repeated measures and linear mixed models assessed treatment effects on outcome measures during and after disbudding. Models accounted for sex, breed, and age as random effects, and Bonferroni adjustments accounted for multiple comparisons. At 15 min after disbudding, XML kids had lower plasma cortisol concentrations compared with L (50.0 ± 13.2 vs. 132.8 ± 13.6 mmol/L) and M kids (50.0 ± 13.2 vs. 145.4 ± 15.7 mmol/L). Cortisol was also lower in XML kids over the first hour after disbudding compared with L kids (43.4 ± 9 vs. 80.2 ± 9 mmol/L). Change from baseline PGE2 was not affected by treatment. Behaviors observed during disbudding did not differ by treatment group. Treatment affected MNT such that M kids were more sensitive overall compared with sham kids (0.93 ± 0.11 kgf vs. 1.35 ± 0.12 kgf). None of the recorded post-disbudding behaviors were affected by treatment, but study activities did influence behavior over time, with kid activity levels declining in the first day after disbudding but largely recovering thereafter. We conclude that none of the drug combinations investigated here appeared to fully attenuate pain indicators during or after disbudding, but triple modality seems to have offered partial relief compared with some of the single-modality treatments.

Combination of mathematics and label-free proteomics for discovering keratin-derived specific peptide biomarkers to distinguish animal horn-derived traditional Chinese medicines.

Saiga antelope horn and Rhinoceros horn have been used in traditional Chinese medicine for thousands of years. However, due to the protection of wildlife, the application of these rare animal horns has been restricted or prohibited. Therefore, water buffalo horn, goat horn, and yak horn have been applied as alternatives to Rhinoceros horn or Saiga antelope horn in a clinic. It is extremely difficult to distinguish normal animal horns in powdered or decocted form, especially identifying related species such as water buffalo horn, yak horn, and cattle horn. In this work, mathematics set and label-free proteomics analysis were combined for discovering keratin-derived specific peptide biomarkers. By using mathematics set analysis after nano liquid chromatography-tandem mass spectrometry-based proteomics, the selected species-specific peptides could be used to identify the authenticity of the Saiga antelope horn and goat horn. Furthermore, peptide biomarkers were selected to distinguish related species-derived horns, water buffalo horn, yak horn, and cattle horn. In total, eight peptide biomarkers were selected and applied for simultaneously distinguishing different horn samples. The present strategy provides a method for peptide biomarkers discovery and also has positive significance for ensuring the quality and efficacy of animal horn-derived traditional Chinese medicines and their products.

How the geometry and mechanics of bighorn sheep horns mitigate the effects of impact and reduce the head injury criterion.

Male bighorn sheep (Ovis canadensis) participate in seasonal ramming bouts that can last for hours, yet they do not appear to suffer significant brain injury. Previous work has shown that the keratin-rich horn and boney horncore may play an important role in mitigating brain injury by reducing brain cavity accelerations through energy dissipating elastic mechanisms. However, the extent to which specific horn shapes (such as the tapered spiral of bighorn sheep) may reduce accelerations post-impact remains unclear. Thus, the goals of this work were to (a) quantify bighorn sheep horn shape, particularly the cross-sectional areal properties related to bending that largely dictate post-impact deformations, and (b) investigate the effects of different tapered horn shapes on reducing post-impact accelerations in an impact model with finite element analysis. Cross-sectional areal properties indicate bighorn sheep horns have a medial-lateral bending preference at the horn tip (p= 0.006), which is likely to dissipate energy through medial-lateral horn tip oscillations after impact. Finite element modeling showed bighorn sheep native horn geometry reduced the head injury criterion (HIC15) by 48% compared to horns with cross-sections rotated by 90° to have a cranial-caudal bending preference, and by 125% compared to a circular tapered spiral model. These results suggest that the tapered spiral horn shape of bighorn sheep is advantageous for dissipating energy through elastic mechanisms following an impact. These findings can be used to broadly inform the design of improved safety equipment and impact systems.

Heat abatement during the pre-weaning period: effects on lying behavior and disbudding-related responses of male Holstein calves.

Strategies to abate heat stress are seldom adopted for pre-weaned dairy calves and little is known about their effects on behavior and pain sensitivity of youngstock. Our objectives were to determine the effects of heat stress abatement on lying behavior and disbudding-related pain sensitivity, wound healing, and change in intake. Male Holstein calves (n = 60; 0 to 68 d of age) were assigned randomly at birth (d 0) to 1 of 3 treatments: hutch outdoors with 50% of its area covered with plywood (control = 20), hutch in a barn with no cooling (SH = 21), and hutch in a barn with ceiling fans (SHF = 19). Calves were fitted with lying-behavior loggers on the hind leg from d 1 to 68. On d 32 ± 8 (±SD), we disbudded calves using hot iron, 30 min after cornual nerves were blocked with lidocaine. Immediately before (0 h), and at 1, 2, and 3 h after disbudding, we evaluated calves for mechanical nociceptive threshold (MNT) and head (ear flick, head shake, head rubbing) and somatic (tail flicking, foot stamping, restlessness) behaviors. On d 1, 3, 7, and 14 after disbudding, we evaluated the MNT and, on d 7 and 14, we evaluated wound healing (1 = crust, 5 = exudate). We calculated the relative change in milk solids and starter intake from d 0 to 6 relative to disbudding compared with the average of the 72 h preceding the procedure. The lying time was 0.6 h/d greater for the SHF treatment compared with the SH treatment. The control treatment resulted in 3.2 and 4.1 more lying bouts per day than the SH and SHF treatments, respectively; consequently, the control treatment resulted in lying-bout duration 7.7 and 10.9 min/event shorter than the SH and SHF treatments, respectively. We did not detect an effect of treatment on the number of disbudding-related head and somatic behaviors and MNT. The odds of calves having abnormal wound was 3.5 and 3.2 times greater for the control treatment compared with the SH and SHF treatments, respectively. We did not detect an effect of treatment on the relative change in intake of milk solids and starter. Heat abatement improves the welfare of pre-weaned dairy calves and may hasten healing.

Dehorning rhinos does not affect productivity.

Georgina Mills discusses new research examining the impact of dehorning black rhinos - a measure that is used to reduce the poaching of this endangered species.

Uncovering Novel Features of the Pc Locus in Horn Development from Gene-Edited Holstein Cattle by RNA-Sequencing Analysis.

The Polled Celtic (Pc) mutation locus is a genetically simple single mutation that is the best choice for breeding polled cattle using gene editing. However, the mechanism of the Pc locus for regulating horn development is unclear, so we used gene editing, somatic cell nuclear transfer and embryo transfer to obtain polled Holstein fetal bovine (gestation time 90 days) with a homozygous Pc insertion (gene-edited Holstein fetal bovine, EH) and the wild-type 90 days Holstein fetal bovine (WH) as controls. The hematoxylin-eosin (HE) staining results showed that, compared to the WH, the EH horn buds had no white keratinized projections or vacuolated keratinocytes and no thick nerve bundles under the dermal tissue. Furthermore, DNA sequencing results showed that the Pc locus was homozygously inserted into the fetal bovine genome. A total of 791 differentially expressed genes were identified by transcriptome sequencing analysis. Enrichment analysis and protein interaction analysis results of differentially expressed genes showed that abundant gene changes after Pc insertion were associated with the adhesion molecule regulation, actin expression, cytoskeletal deformation and keratin expression and keratinization. It was also noted that the results contained several genes that had been reported to be associated with the development of horn traits, such as RXFP2 and TWIST1. This study identified these changes for the first time and summarized them. The results suggested that the Pc mutant locus may inhibit neural crest cell EMT generation and keratin expression, leading to failures in neural crest cell migration and keratinization of the horn bud tissue, regulating the production of the polled phenotype.

Inclusão da ligadura da artéria e veia córnea com abraçadeira de naylon para descorna em bovinos / Inclusion of ligadura artery and vein cornea naylon with the clamp to dehorning in cattle / Inclusión de ligadura arteria y la vena cornea naylon con la pinza para descorne de los bovinos

A descorna cirúrgica a campo ainda e uma prática comum em animais de produção, apesar deste procedimento na maioria ainda se realizado por leigos, ou realizada em animais com menos de um ano de idade com ferro candente (avermelhado), esta conduta geralmente é efetuada na propriedade, sendo executada pelo próprio proprietário ou funcionário. O presente experimento usando anestesia geral e bloqueio local do nervo córneo e circularmente na base do corno com abraçadeira de naylon para sutura de pele, associada a ligadura da artéria e veia cornual mostrou ser eficiente reduzindo o tempo cirúrgico a campo e promovendo uma prevenção antecipada de hemorragia que é frequente para este procedimento.(AU)

The surgical dehorning the field and still a common practice in farm animals, although this procedure in most still held by lay people, or performed on animals less than one year old with red-hot iron (red), this conduct is usually done on the property, being executed by the owner himself or employee. This experiment using general anesthesia and local lock of corneal nerve and round the horn base with clamp naylon for skin suture, associated with ligature of the artery and vein cornual is efficient by reducing surgical time field and promoting an early prevention of bleeding is frequent for this procedure.(AU)

El quirúrgica descorne el campo quieto y una práctica común en los animales de granja, aunque este procedimiento en la mayoría todavía en manos de los laicos, o lleva a cabo en animales de menos de un año de edad con hierro al rojo vivo (rojo), este comportamiento se realiza generalmente en la propiedad, los trabajos realizados por el propietario o el propio empleado. Este experimento usando anestesia bloques general y local de los nervios de la córnea y alrededor de la base del cuerno con naylon pinza de sutura de la piel, asociados con la ligadura de la vena y la arteria cornual fue eficiente que reduce el tiempo quirúrgico el campo y la promoción de una prevención temprana sangrado que es común para este procedimiento.(AU)

Indication of social buffering in disbudded calves.

Most dairy calves are housed individually in early ontogeny but social housing has positive effects on calf welfare including an advantage of social buffering, i.e., when negative effects of stress are mitigated through social support of conspecific. The effects of social buffering has not yet been examined in relation to disbudding; a painful husbandry procedure commonly performed on young dairy calves. The objective of this study was to investigate the effect of pair versus individual housing on calves' behavioral reaction to disbudding. In total 52 female calves were randomly allocated either to individual (n = 16) or pair housing (n = 36, 18 focal). Calves were hot-iron disbudded with a local anesthetic and their spontaneous behavior in home pens was recorded for 24 h pre- and post-disbudding. Eating forage, ruminating, resting, exploration, play, self-grooming, and pain-related behaviors were quantified during eight 20 min intervals during the 24 h periods pre- as well as post-disbudding. In pair-housed (PAIR) calves social resting, active and passive allo-grooming were additionally recorded. The differences between individually housed (INDI, n = 10) and PAIR calves (n = 12) were tested by general linear models. The changes in pre- and post-disbudding behaviors in all calves as well as in social behaviors of PAIR calves were tested by paired t-test. We found that head shaking (t = - 3.46, P = 0.0024), head rubbing (t = 4.96, P < 0.0001) and self-grooming (t = 2.11, P = 0.04) increased in all calves after disbudding. Eating forage increased only in PAIR calves (t = 2.50, P = 0.030) which also resulted in a difference between treatments with PAIR calves fed more often than INDI calves (F1,18 = 12.96, P = 0.002). Differences in eating forage may be an indication of improved ability of PAIR calves to recover from disbudding. No other significant differences were detected between treatment groups which might have been caused by our limited sample. Our results provide the first evidence that housing treatment affects calves' reactions to disbudding, with possible indication of social buffering.

Graduate Student Literature Review: Role of pain mitigation on the welfare of dairy calves undergoing disbudding.

This review synthesizes research findings on the pain and welfare of dairy calves undergoing disbudding procedures. We describe disbudding practices in North America as well as the use and perceptions of pain control for these procedures. Governing bodies across Canada and the United States, including each country's veterinary medical association and nationwide initiatives such as proAction and Farmers Assuring Responsible Management (FARM), recommend or require the use of a local anesthetic, a nonsteroidal anti-inflammatory drug (NSAID), and a sedative for disbudding procedures. Although the use of pain relief for disbudding has increased over the past decade or so, some in the dairy industry still do not believe that pain control for disbudding is necessary. As a painful procedure, disbudding has numerous welfare impacts on the calf both during and following the procedure that can be categorized under all 3 principles of animal welfare: natural living, biological functioning, and affective state. The use of pain control for disbudding; namely, a local anesthetic and NSAID, can improve welfare outcomes such as procedure-induced pain behavior, cortisol concentrations, mechanical nociceptive threshold, emotional states, and so on, compared with no pain control for the procedure. Although extensive research exists on pain control practices for disbudding, this review identified further gaps in knowledge and areas for future research. Mechanical nociceptive threshold can be evaluated around the disbudding wounds and is a reliable test in older calves; however, this outcome in very young calves after caustic paste disbudding has been reported to be inconclusive compared with that in older calves. As well, research evaluating xylazine sedation for disbudding has reported both potentially positive and negative results that are difficult to interpret or base suggestions on for the use of this drug. Finally, wounds caused by disbudding take a long time to heal (up to 13 wk) and have increased sensitivity for the entire healing process. Therefore, future research should aim to (1) determine accurate behavioral tests for calves under 1 wk of age undergoing disbudding to better understand their experience, (2) further attempt to understand the effects of xylazine sedation for disbudding and potential impacts of providing this medication, and (3) determine more ways to reduce the healing time and pain experienced by the calf after disbudding procedures.