Efficacy of a novel cervical dislocation tool for humane euthanasia of broilers and broiler breeders

Euthanasia is an essential task performed daily on commercial poultry farms around the world to safeguard animal welfare. Manual cervical dislocation (MCD) is the most common euthanasia method but can be challenging to perform given the physical strength required to implement this technique. Therefore, the objective of this study was to evaluate the efficacy of a novel cervical dislocation tool (NCDT) compared to MCD. A total of 60 Ross 308 chickens (6-wk old) and 60 Ross 706 parent stock breeders (21-wk old) were enrolled in the study. Birds were sexed, blocked by body weight, and allocated to 1 of 2 treatments: 1) MCD and 2) NCDT. Immediately following euthanasia application, insensibility, and death were monitored. Once death was confirmed, gross evaluation, radiograph, and macroscopic/microscopic scoring were performed. Both euthanasia methods were 100% effective in achieving insensibility followed by cardiac and respiratory arrest in both age groups. In 6-wk-old broilers, there were no differences in insensibility measures or location and severity of the dislocation site by treatment. The NCDT treatment group showed an increased frequency of fractures located at the tooth-like process that projects from the cranial aspect of the centrum of the axis (dens) but had no impact on bird insensibility. For parent stock, differences in nictitating membrane reflex (NMR) and laceration scores for birds euthanized with NCDT were found and likely associated with additional force exerted with the tool. The NCDT is a promising replacement for MCD and future work should address the development of free and accessible training materials for on-farm use.

A decade on: where is the UK poultry industry for emergency on-farm killing?

Millions of poultry are farmed intensively every year across the United Kingdom (UK) to produce both meat and eggs. There are inevitable situations that require birds to be emergency killed on farm to alleviate pain and suffering. In Europe and the UK, emergency methods are regulated by the European Council Regulation (EC) No. 1099/2009 and The Welfare of Animals at the Time of Killing Regulations (England 2015; Scotland 2012; Wales and Northern Ireland 2014). Cervical dislocation has been reported to be the most widely used method prior to these legislative changes which took place from 1 January 2013. Based on limited scientific evidence and concern for bird welfare, these legislative changes incorporated restrictions based on bird weight for both manual (≤3 kg) and mechanical (≤5 kg) cervical dislocation, and introduced an upper limit in the number of applications for manual cervical dislocation (up to 70 birds per person per day). Furthermore, it removed methods which showed evidence of crushing injury to the neck. However, since legal reform new scientific evidence surrounding the welfare consequences of cervical dislocation and the development of novel methods for killing poultry in small numbers on farm have become available. Whether the UK poultry industry have adopted these novel methods, and whether legislative reform resulted in a change in the use of cervical dislocation in the UK remains unknown. Responses from 215 respondents working across the UK poultry industry were obtained. Despite legal reform, manual cervical dislocation remains the most prevalent method used across the UK for killing poultry on farm (used by 100% of farms) and remains the preferred method amongst respondents (81.9%). The use of alternative methods such as Livetec Nex® and captive bolt guns were available to less than half of individuals and were not frequently employed for broilers and laying hens. Our data suggests there is a lack of a clear alternative to manual cervical dislocation for individuals working with larger species and a lack of gold standard methodology. This risks bird welfare at killing and contributes to inconsistency across the industry. We suggest providing stakeholders with practical alternatives prior to imposing legislative changes and effective knowledge transfer between the scientific community and stakeholders to promote positive change and protect bird welfare.

Efficacy of three different cervical dislocation methods for on-farm killing of layer chicks

Unfit chicks with low viability are often euthanized in the layer industry. An effective euthanasia protocol is characterized by rapid, irreversible insensibility, followed by prompt death. This study was conducted to evaluate the efficacy of three cervical dislocation methods for killing layer chicks (2-3-day-old, avg BW ± SD; 44 ± 3 g, n = 40): manual cervical dislocation (CD), assisted manual cervical dislocation (ACD; the bird's ventral neck is placed on a blunt table edge and the back of the neck pressed firmly), and mechanical cervical dislocation by Koechner Euthanizing Device (KED-model-S). All three killing methods were assessed on anesthetized chicks (intramuscular injections of medetomidine [0.3 mg/kg BW] and ketamine [30 mg/kg BW] were used to induce clinical anesthesia). CD and ACD were also evaluated using conscious chicks to compare the killing methods and to determine the effect of anesthesia on response variables. There were no differences in time to loss of pupillary light reflex, cessation of heartbeat, or duration of gasping between conscious chicks killed with CD and ACD, but these values were all longer for conscious compared to anesthetized chicks. KED resulted in longer latencies to loss of pupillary light reflex, cessation of heartbeat, and duration of gasping. Radiographs revealed that both CD and ACD resulted in cervical luxation, mainly below the C4 vertebra, whereas KED did not cause luxation in any of the 8 chicks tested. Chicks killed by CD and ACD presented more subdural hemorrhage (SDH) at the site of cervical dislocation than those killed by KED. None of the killing methods resulted in brain trauma. Compared to CD and ACD, KED resulted in longer latency to brain death and less anatomical pathology indicating a lower efficacy of KED as an on-farm killing method.

Awake Cranial Traction and Isolated Anterior Cervical Discectomy and Fusion in the Treatment of Traumatic Subaxial Cervical Facet Joint Dislocations: Analysis of a Cohort of 70 Patients and Predictors of Surgical Failure

BACKGROUND

Cervical facet dislocations are among the most common traumatic spinal injuries. The management of this type of lesions is still controversial. The objective of the present study was to analyze the results of subaxial cervical facet dislocations submitted to an isolated anterior cervical discectomy and fusion (ACDF) after attempted closed reduction with cranial traction and to identify risk factors for treatment failure.

METHODS

All patients who were operated on in a tertiary trauma center during an 11-year period (2008-2018) for traumatic single-level cervical facet joint dislocation (AO C F4 injuries) were retrospectively reviewed. Age, use of cranial traction, dislocation characteristics, neurologic injury, surgical data, and follow-up records were reviewed. A minimum of 18 months follow-up was required.

RESULTS

A total of 70 patients with a mean age of 56 years (18-90) (72% men) were identified. The C6-C7 level was the most frequently affected (36/70 cases). Spinal cord injury (SCI) was present in 34% of the cases. Bilateral dislocations and rigid spines were risk factors for SCI. Cranial traction was performed in 59 cases with success in 52 cases (88%). There were 3 failures after anterior fusion, which required revision surgery with a 360° fusion, all occurring at the C7-T1 level.

CONCLUSIONS

Cranial traction of the cervical spine is an effective and fast way to achieve closed reduction of cervical facet dislocations. After successful reduction, ACDF, as a single procedure, offers an excellent surgical option. All cases of failure occurred at the C7-T1 level, suggesting that a 360° fusion may be needed at this level.

LEVEL OF EVIDENCE: 3

The efficacy of three on-farm euthanasia methods for broiler chickens throughout the production cycle

1. There is a need to humanely kill moribund or injured broiler birds on-farm with no reasonable chance of recovery. Two experiments evaluated the efficacy of three commercially applicable killing methods; manual cervical dislocation (CD), mechanical cervical dislocation with the Koechner Euthanising Device (KED) and a non-penetrative captive bolt device (Zephyr-EXL; ZEXL), at 7, 21 or 35 d of age, on their ability to induce insensibility (unconsciousness and loss of brain stem reflexes) and death.2. Experiment one assessed the damage to the cranial-cervical region resulting from the methods applied to cadavers of cull birds (n = 180) by radiography and gross pathology observation.3. Experiment two evaluated the latency to insensibility and death when cull broiler birds (n = 240) were killed by CD, KED or ZEXL, using behavioural and reflexive indicators. Insensibility and death were measured by the absence of pupillary light, palpebral blink and nictitating membrane reflexes and cessation of rhythmic breathing, cloacal winking and convulsions. Analysis of variance for the main effect of the method was performed to determine the differences.4. In experiment one, only the Zephyr resulted in skull fractures. A higher number of vertebral fractures occurred with KED application compared to CD, at 21 and 35 d.5. In experiment two, indicators of sensibility were absent earliest with the ZEXL (μ < 2 s); then,CD (μ = 28 s) and were longest with KED (μ = 47 s), at 21 and 35 d. Cloacal winking and convulsions ceased earlier after CD (88 s), compared to either KED (124 s) or Zephyr (118 s). Death after a single application occurred 100%, 100% and 98% of time for CD, KED and ZEXL, respectively.6. Overall, all methods were efficacious at inducing insensibility and death. Insensibility occurred earliest with ZEXL, whilst death occurred earliest with CD. KED resulted in the longest time to insensibility and death.

Comparing various euthanasia devices and methods on 8 and 12-week-old turkey hens

On-farm euthanasia of poultry is a necessity for minimizing disease spread and removing sick or injured birds to maintain optimum animal welfare. There are numerous methods that are approved for euthanasia of poultry by organizations like the American Veterinary Medical Association; however, all approved methods are not easily carried out on-farm or as effective as one another. Therefore, the objective of this study was to compare several captive bolt devices (Turkey Euthanasia Device, Zephyr-EXL, Jarvis Stunner, Experimental Crossbow), mechanical cervical dislocation (Broomstick method [BRM] and Koechner Euthanasia Device [KED]), and manual cervical dislocation (MAN) methods on 8 and 12-week-old turkey hens. Each method was assessed for impact on loss of brain stem reflexes, euthanasia success, and torn skin. The cervical dislocation techniques were also analyzed via radiograph for proper dislocation. Furthermore, each device was assessed for physical parameters. Turkeys (n = 1,400) were euthanized on 20 sampling days, 10 sampling days for each age period. All methods resulted in euthanasia of all turkeys in this study. The captive bolt devices all resulted in immediate loss of nictitating membrane and pupillary reflex at both the ages tested. The cervical dislocation methods differed in both nictitating membrane and pupillary reflex cessation at both ages (P < 0.05). The pattern was the same at both ages with the KED device have longer latencies to cessation of both reflexes when compared to the BRM and MAN methods (P < 0.05). Cessation of movement was also generally longer in dislocation methods compared to captive bolt at both ages. However, captive bolt devices resulted in more lacerations of the skin in general. MAN was also found to result in less damage to the vertebrae and proper location of separation than the mechanical methods of dislocation. All methods resulted in effective euthanasia; however, captive bolt methods resulted in immediate loss of brain stem reflexes indicating that they maybe more humane than cervical dislocation methods.

Evaluation of Brain Death in Laying Hens During On-Farm Killing by Cervical Dislocation Methods or Pentobarbital Sodium Injection

This study investigated changes in the electroencephalograph (EEG) power spectrum as well as physiological and behavioral responses to on-farm killing via mechanical cervical dislocation (MCD), manual cervical dislocation (CD) or intravenous pentobarbital sodium administration in lightly anesthetized laying hens, to evaluate the welfare impact of each method. A mixed group of 44 white Leghorn and Smoky Joe laying hens (60 weeks-old) were anesthetized with isoflurane in oxygen and maintained at 1.5–2% isoflurane/O₂ until the killing method was applied. Birds were randomly assigned to one of three experimental groups on each trial day. The EEG was recorded bilaterally in a four-electrode montage. After recording a 5-min baseline, the killing method was applied and EEGs and other behavioral and physiological responses, including convulsions, gasping, cessation of body movements and feather erection were recorded for 5 min. Changes in EEG frequency bands (alpha, beta, delta, theta), median frequency (F50), 95% spectral edge frequency (F95), and total power (Ptot) were used to assess the quality of the on-farm killing event. Within 15 s after administration of pentobarbital sodium, there were significant decreases in mean frequency bands, increases in mean F50 and F95, and decreases in Ptot, suggesting brain death. In addition, birds presented a shorter latency to cessation of movement after pentobarbital sodium injection compared to MCD and CD (22 vs. 115 s and 136 s, respectively). There were significant increases in F95 and decreases in Ptot at 120 s after application of CD; and a concomitant decrease in the frequency bands at 135 s and isoelectric EEG at 171 ± 15 s. Changes consistent with brain death after MCD included isoelectric EEG at 207 ± 23 s and a significant decreases in some frequency bands at 300 s post-application. No other significant spectrum frequency changes were observed in the MCD group, suggesting brain death likely occurred near the 5-min endpoint. There was no clear association between behavioral, physiological, and EEG responses within CD and MCD treatments. The data demonstrate that pentobarbital sodium induced a rapid death with minimal behavioral and physiological responses regardless of strain of hens. In comparison, use of CD and MCD resulted in a slow onset of brain death in hens.

Efficacy of a Novel Mechanical Cervical Dislocation Device in Comparison to Manual Cervical Dislocation in Layer Chickens

Simple Summary

On-farm euthanasia of diseased or injured chickens is a common task within the poultry industry. For animal welfare, the aim of any euthanasia technique is to achieve rapid loss of sensibility, for the process to cause minimal pain, and for death to follow quickly. Manual cervical dislocation (separating the skull from the spine by hand) is a common method for killing poultry on farms, but it can be aesthetically displeasing. Therefore, different tools for neck dislocation (separating the skull from the spine by mechanical device) are developed as alternative euthanasia methods. These tools need scientific assessment for their effectiveness and humaneness. The Koechner Euthanasia Device (KED) (Koechner MFG. CO., INC, USA) is commercially available as a mechanical cervical dislocation tool for poultry. We compared the efficacy of KED with manual cervical dislocation based on time to brain death (irreversible insensibility) and degree of damage to the brain and neck in anesthetized chickens. The anesthetic agents reduced any distress and pain associated with the killing technique. Our results indicated that KED resulted in less damage to the brain, causing longer times to brain death and cardiac arrest in comparison to manual cervical dislocation. We suggest that manual cervical dislocation is more efficient and humane for layer chicken euthanasia than KED.

Abstract

The main objective of this study was to assess the efficacy of mechanical cervical dislocation using the Koechner Euthanasia Device Model C (KED) in comparison to manual cervical dislocation in layer chickens. Laying hens and/or roosters in three different age groups (12, 27–29, and 65–70 weeks old) were randomly assigned to one of three experimental groups: manual cervical dislocation in conscious birds (CD), manual cervical dislocation in anesthetized birds (aCD), or mechanical cervical dislocation by KED in anesthetized birds (aMCD). Anesthetized birds received an intramuscular dose of 0.3 mg/kg medetomidine and 30 mg/kg of ketamine to achieve clinical anesthesia. A comparison of CD vs. aCD responses confirmed that the anesthetic plane abolished or reduced clonic convulsions, nictitating membrane reflex, tonic convulsions, and cloacal relaxation. Time to loss of the pupillary light reflex (~123 s), and time to cardiac arrest (~172 s) were longer (p < 0.001) in the birds in the aMCD group than aCD (~71 and ~137 s, respectively). Radiographs revealed that the majority of the birds killed by manual cervical dislocation (CD + aCD) had dislocations between the skull and atlas (C1) or between cervical vertebrae C1–C2. The KED resulted in a majority of dislocations at C2–C3. Birds killed by manual cervical dislocation presented more subdural and parenchymal hemorrhage in the brain stem compared to birds killed by KED. Radiographs indicated the presence of fractures in a few birds killed by either method (CD + aCD versus aMCD). Compared to manual CD, KED resulted in less brain trauma and a longer latency to brain death, indicating a lower efficacy of KED as an on-farm killing method.

Euthanasia via CO2 inhalation causes premature cortical granule exocytosis in mouse oocytes and influences in vitro fertilization and embryo development

Generation of high quality mouse metaphase II oocytes is an integral part for efficient in vitro fertilization (IVF), and subsequent embryo production for reproductive studies and genome banking. The main objectives of this study were to investigate the impact of various euthanasia methods on IVF, embryo development, and subcellular structures of MII mouse oocytes. Following superovulation regimen, female mice were euthanized by high flow CO₂ (H CO₂ ), low flow CO₂ (L CO₂ ), or cervical dislocation (CD). The MII oocytes obtained from these mice were evaluated for subcellular integrity by assessing their cortical granules and F-actin. Furthermore, fertilization and subsequent embryonic development competence up to blastocyst stage were also evaluated in vitro. The oocytes collected from females euthanized by CD resulted in significantly higher two-cell development rates (p = 0.028) and subsequently lead to in higher embryo development rates (p = 0.027) compared with oocytes from females euthanized by L CO₂ . The cortical granule integrity analysis revealed significantly higher rate of premature cortical granules exocytosis (PCGE) for L CO₂ group compared with CD and H CO₂ groups (p < 0.001). These data collectively suggest that CO₂ associated PCGE during euthanasia procedure is the main cause of decreased IVF rates and CD is the optimal euthanasia method for the purpose of obtaining good quality MII oocytes for mouse IVF and other reproductive studies.

Euthanasia: Manual versus Mechanical Cervical Dislocation for Broilers

Simple Summary

Poultry are euthanized for several reasons, most commonly because a bird is sick or injured and unable to eat or drink. Euthanasia can be a challenge to perform, especially when birds are heavy, like broiler chickens (produced for meat). Manual cervical dislocation (CD), or “breaking the neck”, is the most commonly applied method, but can be challenging. Therefore, using a tool (the mechanical method) such as the Koechner Euthanizing Device (KED) could be an alternative. Here, we aimed to compare CD with KED application for their impact on duration of induced reflexes and time to brain death. We assessed loss of brain stem reflexes, which indicate deep unconsciousness and/or brain stem death, and cessation of musculoskeletal movements. We applied both methods (CD and KED) to 200 broilers of 36, 42, or 43 days old on 3 experimental days. On days 2 and 3 an additional method was added, in which the bird’s head was extended at a ~90° angle after the application of the KED (KED+). Our study indicated brain stem death occurred sooner when birds were euthanized with CD compared to KED or KED+; all reflex durations were sustained for longer in the KED and KED+ birds.

Abstract

The aim was to assess the onset of brain stem death for two euthanasia methods—manual cervical dislocation (CD) versus the Koechner Euthanizing Device (KED). Over three days broilers of 36 (n = 60), 42 (n = 80), or 43 days old (n = 60) were euthanized. On days 2 and 3, a treatment was added in which the bird’s head was extended at a ~90° angle after application of the KED (KED+). On those days, gap size was recorded between the skull and atlas vertebra by 1-cm increments. The onset of brain death was assessed by recording the nictitating membrane reflex, gasping reflex and musculoskeletal movements (sec). Additionally, skin damage and blood loss were recorded (y/n). On all days, CD resulted in quicker loss of reflexes and movements compared to KED or KED+. Reflexes returned in 0–15% of CD birds, 50–55% of KED birds, and 40–60% of KED+ birds, possibly regaining consciousness. Skin damage occurred in 0% of CD birds, 68–95% of KED birds, and 85–95% of KED+ birds. On day 2 (p = 0.065) and 3 (p = 0.008), KED birds had or tended to have a narrower skull-to-atlas gap compared to CD and KED+ birds. Based on our results, CD would be the recommended method for broilers.

Assessing a Method of Mechanical Cervical Dislocation as a Humane Option for On-Farm Killing Using Anesthetized Poults and Young Turkeys

Our objective was to determine the efficacy of manual cervical dislocation vs. a mechanical cervical dislocation device for on-farm killing of poults and young turkeys. Forty-two 1- and 3-week old turkeys were randomly assigned to one of three experimental groups: awake manual cervical dislocation (CD), anesthetized manual cervical dislocation (aCD), or anesthetized mechanical cervical dislocation (MCD). Anesthetized birds received an intramuscular dose of 0.3 mg/kg medetomidine and 30 mg/kg of ketamine to achieve a light plane of anesthesia. A comparison of CD vs. aCD responses indicated that the anesthetic plane did not affect jaw tone or pupillary light reflex, indicators of loss of sensibility and brain death, respectively. MCD was unsuccessful for killing 1-week old poults as indicated by the ongoing presence of the pupillary eye reflex as well as failure to achieve cardiac arrest within 5 min in 5 of 5 birds. Radiographs also indicated no vertebral dislocation or fracture. Pupillary light reflex was present in 98% and jaw tone was present in 73% of turkeys, respectively, for all groups combined, but retention of the pupillary light reflex (P < 0.001) and jaw tone (P = 0.001) was longer for birds killed by MCD. Time to last movement (P = 0.797) and cardiac arrest (P = 0.057) did not differ between method. Survey radiographs demonstrated an effect of method for the average displacement distance at the site of vertebral dislocation, with a greater distance observed in birds killed by CD compared to MCD (P = 0.003). A method by age interaction was observed between CD and MCD for the number of birds with fractures; more vertebral fractures were observed in 3-week old turkeys killed with MCD compared to CD (P = 0.047). Upon gross examination, the majority of birds killed by either method had minimal to no hemorrhage within the brain and spinal cord. However, turkeys killed using CD had more microscopic subdural brain hemorrhage (P = 0.020). Ante-mortem and post-mortem measures suggest that neither manual CD nor the MCD tool used in this study caused immediate insensibility, but CD resulted in a shorter latency to brain death and fewer fractures compared to MCD.

Welfare Risks of Repeated Application of On-Farm Killing Methods for Poultry

Simple Summary

During poultry production, some birds are killed humanely on farm, usually because they are ill or injured. Recent European Union (EU) legislation has restricted the number of birds that can be killed by manual neck dislocation to 70 birds per person per day. We examined whether this limit is meaningful by investigating the effects of repeated application of two methods of killing (neck dislocation and a percussive method, the CashPoultry Killer). Twelve male stockworkers each killed 100 birds (broilers, laying hens, or turkeys) at a fixed rate with each method. Both methods were highly successful, and reflex and behaviour measures confirmed they caused rapid loss of brain function. Importantly, there was no evidence of reduced performance with time/bird number up to 100 birds with either method. The Cash Poultry Killer caused a more rapid death, but it was prone to technical difficulties with repeated use. Neck dislocation has the important advantage that it can be performed immediately with no equipment, which may make it preferable in some situations. We present the first evidence that, at the killing rates tested, there was no evidence to justify the current EU number limit for performance of neck dislocation to kill poultry on farm.

Abstract

Council Regulation (EC) no. 1099/2009 on the protection of animals at the time of killing restricts the use of manual cervical dislocation in poultry on farms in the European Union (EU) to birds weighing up to 3 kg and 70 birds per person per day. However, few studies have examined whether repeated application of manual cervical dislocation has welfare implications and whether these are dependent on individual operator skill or susceptibility to fatigue. We investigated the effects of repeated application (100 birds at a fixed killing rate of 1 bird per 2 min) and multiple operators on two methods of killing of broilers, laying hens, and turkeys in commercial settings. We compared the efficacy and welfare impact of repeated application of cervical dislocation and a percussive killer (Cash Poultry Killer, CPK), using 12 male stockworkers on three farms (one farm per bird type). Both methods achieved over 96% kill success at the first attempt. The killing methods were equally effective for each bird type and there was no evidence of reduced performance with time and/or bird number. Both methods of killing caused a rapid loss of reflexes, indicating loss of brain function. There was more variation in reflex durations and post-mortem damage in birds killed by cervical dislocation than that found using CPK. High neck dislocation was associated with improved kill success and more rapid loss of reflexes. The CPK caused damage to multiple brain areas with little variation. Overall, the CPK was associated with faster abolition of reflexes, with fewer birds exhibiting them at all, suggestive of better welfare outcomes. However, technical difficulties with the CPK highlighted the advantages of cervical dislocation, which can be performed immediately with no equipment. At the killing rates tested, we did not find evidence to justify the current EU limit on the number of birds that one operator can kill on–farm by manual cervical dislocation.

On Farm Evaluation of a Novel Mechanical Cervical Dislocation Device for Poultry

Urgent development of alternative on-farm killing methods for poultry is required following the number restrictions placed on the use of traditional manual cervical dislocation by European Legislation (EU 1099/2009). Alternatives must be proven to be humane and, crucially, practical in commercial settings with multiple users. We assessed the performance and reliability of a novel mechanical cervical dislocation device (NMCD) compared to the traditional manual cervical dislocation (MCD) method. NMCD was based on a novel device consisting of a thin supportive glove and two moveable metal finger inserts designed to aid the twisting motion of cervical dislocation. We employed a 2 × 2 factorial design, with a total of eight stockworkers from broiler and layer units (four per farm) each killing 70 birds per method. A successful kill performance was defined as immediate absence of rhythmic breathing and nictitating membrane reflex; a detectable gap in the vertebrae and only one kill attempt (i.e., one stretch and twist motion). The mean stockworker kill performance was significantly higher for MCD (98.4 ± 0.5%) compared to NMCD (81.6 ± 1.8%). However, the MCD technique normally used by the stockworkers (based previous in-house training received) affected the performance of NMCD and was confounded by unit type (broilers), with the majority of broiler stockworkers trained in a non-standard technique, making adaption to the NMCD more difficult. The consistency of trauma induced by the killing methods (based on several post-mortem parameters) was higher with NMCD demonstrated by "gold standard" trauma achieved in 30.2% of birds, compared to 11.4% for MCD (e.g., dislocation higher up the cervical region of the spine i.e., between vertebrae C0-C1, ≥1 carotid arteries severed), suggesting it has the potential to improve welfare at killing. However, the results also suggest that the NMCD method requires further refinement and training optimization in order for it to be acceptable as an alternative across poultry industry, irrespective of previous MCD technique and training.

Assessment of the Effects of Graded Doses of Polyphenolic-Rich Fraction of Garcinia kola Seeds on Pituitary-Testicular Axis of Male Wistar Rats

This study evaluated the ameliorative and prophylactic effects of 2 different doses of polyphenolic-rich fraction of Garcinia kola (PPRFGk) seeds on the histology and hormones of pituitary–testicular axis of male Wistar rats. Thirty-five male Wistar rats (150-200 g) were divided into 7 groups of 5 rats each. Groups I and II were given distilled water (0.5 mL/day) for 8 days followed by propylene glycol (0.2 mL/d) and 600 mg/kg of PPRFGk, respectively, for 21 days. Group III received sodium arsenate (8 days), left untreated for 21 days. Groups IV and V received sodium arsenate (20 mg/kg) for 8 days followed by PPRFGk (300 and 600 mg/kg, respectively) for 21 days. Groups VI and VII received PPRFGk (300 and 600 mg/kg, respectively) for 21 days followed by sodium arsenate (20 mg/kg) for 8 days. Rats were killed by cervical dislocation 24 hours after the last dose and their blood collected through cardiac puncture. Blood sera were assayed for the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone using immunoassay techniques. Histology of the pituitary gland and testes was carried out. A significant reduction was observed in the concentration of FSH in groups IV, V, VI, and VII in comparison with groups I and II. The concentrations of both LH and testosterone showed significant decreases in groups IV, V, VI, and VII in comparison with group I. Group III presented with the lowest serum hormonal concentrations. Photomicrographs of the pituitary gland revealed greatly reduced basophils in group III and mildly reduced basophils in groups IV, VI, and VII in comparison with groups I and II. Group V revealed hypercellularized and distorted basophils. Photomicrographs of the testes showed detachment of the seminiferous tubules from the basement membrane and disruption of the interstitial space which was worse in group III, moderate in groups V and VI, and mild in group VII. In conclusion, PPRFGk effected a dose-dependent reversal and prevention of the perturbations caused by arsenate in rats.

Traumatic Cervical Unilateral and Bilateral Facet Dislocations Treated With Anterior Cervical Discectomy and Fusion Has a Low Failure Rate

STUDY DESIGN

Retrospective radiographic and chart review.

OBJECTIVE

To define the rate and associated risk factors of treatment failure of anterior cervical fusion for treatment of cervical facet dislocations.

METHODS

Between 2004 and 2014, a retrospective review at a single level 1 trauma center identified 38 patients with unilateral or bilateral dislocated facet(s) treated with anterior cervical discectomy and fusion (ACDF). Two patients were eliminated due to less than 30-day follow-up. Demographic data, initial neurological exams, surgical data, radiographic findings, and follow-up records were reviewed.

RESULTS

Of the 36 patients with facet dislocations treated with ACDF using a fixed locking plate, 16 were unilateral and 20 were bilateral. The mean age was 35 years (range 13-58). Mean follow-up was 323 days (range 30-1998). There were 3 treatment failures (8%). Three of 7 (43%) endplate fractures failed (P < .01), and 1/28 (4%) facet fractures failed (P = .13). The mean time to failure was 4 weeks (1-7 weeks). One treatment failure had a facet fracture, and all 3 failures had an associated endplate fracture.

CONCLUSION

Treatment failure occurred in 3 out of 36 (8%) patients with facet fracture dislocations treated with anterior cervical discectomy, fusion, and plating. Rates of failure are lower than has been previously reported. Endplate fractures of the inferior level in jumped facets appears to be a major risk factor of biomechanical failure. However, a facet fracture may not be a risk factor for failure. In the absence of an endplate fracture, ACDF is a reasonable treatment option in patients with single-level cervical facet dislocation.

Evaluation of the potential killing performance of novel percussive and cervical dislocation tools in chicken cadavers

1. Four mechanical poultry killing devices; modified Armadillo (MARM), modified Rabbit Zinger (MZIN), modified pliers (MPLI) and a novel mechanical cervical dislocation (NMCD) gloved device, were assessed for their killing potential in the cadavers of euthanised birds. 2. A 4 × 4 × 4 factorial design (batch × device × bird type + age) was employed. Ten bird cadavers per bird type and age were tested with each of the 4 devices (N = 160 birds). All cadavers were examined post-mortem to establish the anatomical damage caused. 3. NMCD, MARM and MZIN demonstrated killing potential, as well as consistency in their anatomical effects. NMCD had the highest killing potential, with 100% of birds sustaining the required physical trauma to have caused rapid death. 4. The MPLI was inconsistent, and only performed optimally for 27.5% of birds. Severe crushing injury was seen in >50% of MPLI birds, suggesting that birds would die of asphyxia rather than cerebral ischaemia, a major welfare concern. As a result, the MPLI are not recommended as a humane on-farm killing device for chickens. 5. This experiment provides important data on the killing potential of untried novel percussive and mechanical cervical dislocation methods, informing future studies.