Browsing by Author "Jacobs, Leonie"

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    Animal welfare assessment of on-farm euthanasia methods for individual, heavy turkeys
    Jacobs, Leonie; Bourassa, Dianna V.; Boyal, Ranjit S.; Harris, Caitlin E.; Josselson, L. Nicole Bartenfeld; Campbell, Andrew M.; Anderson, Gracie; Buhr, R. Jeff (2021-03)
    On-farm euthanasia of poultry, including turkeys, may not be possible for most people as birds gain weight; thus alternative mechanical methods have been developed. Our objective was to compare mechanical cervical dislocation with the Koechner Euthanizing Device (KED), captive bolt euthanasia with the Turkey Euthanasia Device (TED), head-only CO2 euthanasia (CO2), and electric euthanasia as potential humane methods for euthanizing individual, heavy turkeys. We assessed their impact on loss of brain stem reflexes, acute distress (corticosterone, CORT), kill success, torn skin, and blood loss. Turkeys (n 5 174) were euthanized on 3 sampling days, while birds were restrained using a mobile bird euthanasia apparatus. Brain stem reflexes recorded were the cessation and return of induced nictitating membrane reflex (loss of consciousness and brain stem dysfunction), mouth gaping reflex (brain stem dysfunction), and musculoskeletal movements (spinal cord dysfunction). Overall, KED resulted in more frequent (at 4 min: KED 7 of 14; electric 0 of 13; TED 0 of 11; CO2 2 of 14 birds on day 1) and longer durations of the induced nictitating reflex compared to the other methods (means of day 2 and 3: KED 233; electric 15; TED 15; CO2 15 s). The mouth gaping reflex endured the longest after KED euthanasia (means of day 2 and 3: KED 197; electric 15; TED 51; CO2 15 s). Musculoskeletal movements endured longest after KED euthanasia (means of day 2 and 3: KED 235; electric 15; TED 219; CO2 15 s). Returning reflexes were more frequent after KED and TED compared to CO2 and electric euthanasia, where it was absent. CO2, electric, and TED euthanasia showed comparable kill success (success: CO2 42 out of 43; electric 44 of 45; TED 42 of 44), with KED resulting in most unsuccessful kills (unsuccessful: 8 out of 42). CORT responses were inconsistent. Torn skin and blood loss occurred more frequently after KED and TED compared to CO2 and electric applications. Therefore, we conclude that, based on a comparison of these 4 methods, the most discernibly humane was electric euthanasia, which consistently resulted in quick loss of consciousness within 15 s, no returning reflexes, and no torn skin or blood loss.
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    Animal Welfare Standards and Marketing
    Jacobs, Leonie; Bovay, John; Pierce, Timothy (Virginia Cooperative Extension, 2021)
    This handout provides an overview of animal welfare economics and the benefits to farmers from marketing their commitments to animal welfare.
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    Broiler Chicken Behavior and Activity Are Affected by Novel Flooring Treatments
    Jacobs, Leonie; Melick, Shawnna; Freeman, Nathan; Garmyn, An; Tuyttens, Frank A. M. (MDPI, 2021-09-29)
    The objective was to determine broiler chicken behavioral differences in response to novel flooring treatments. Broilers (n = 182) were housed in 14 pens (a random subset from a larger-scale study including 42 pens), with 13 birds/pen. One of seven flooring treatments were randomly allocated to 14 pens (2 pens per treatment). The flooring treatments (provided from day 1 {1} or day 29 {29}) included regularly replaced shavings (POS), a mat with 1% povidone-iodine solution (MAT), and the iodine mat placed on a partially slatted floor (SLAT). In addition, a negative control treatment was included with birds kept on used litter from day 1 (NEG). Behavior was recorded in weeks 1, 2, 5, and 6. In week 5, treatments affected the behavioral repertoire (p ≤ 0.035). Birds in POS-1 showed more locomoting, preening and activity overall compared to MAT and/or SLAT treatments. Birds in POS-29 showed more drinking, foraging, preening and overall activity than birds in MAT and/or SLAT treatments. In week 6, birds in the POS-1 treatment spent more time foraging compared to birds in all MAT and SLAT treatments (p ≤ 0.030). In addition, birds in the POS-1 treatment spent more time preening than birds in the MAT-1 treatment (p = 0.046). Our results indicate that access to partially slatted flooring and/or disinfectant mats does not benefit broiler chicken welfare in terms of their ability to express highly motivated behaviors. Access to clean, regularly replaced litter is beneficial for broiler chicken welfare in terms of their ability to express their normal behavioral repertoire.
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    Broiler Chicken Welfare during Pre-Slaughter Transport
    Jacobs, Leonie (Eurogroup For Animals, 2020-01-31)
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    Castration in the U.S. Swine Industry: Animal Welfare Implications and Alternatives
    Jacobs, Leonie; Neary, Jessica (Virginia Cooperative Extension, 2020-12-11)
    Removal of the testicles (castration) is a prevalent procedure within the US swine industry. Because only a small percentage of swine are selected for mating, the vast majority of male piglets (boars) are destined for processing (meat production) and are castrated. Boars are castrated to limit behavioral issues during rearing, and to ensure appropriate meat quality, by avoiding 'boar taint'. As the boars grow and mature, they may develop aggressive tendencies towards their pen mates, and attempt to mate with females in the pen. These behaviors could increase the risk of lameness and injury for both boars and their pen mates. Mature boars could also be aggressive towards farm staff. Surgical castration is the most common method of castration in the US. However, a relatively new option for producers is immunocastration, and some are transitioning to this. Here we discuss considerations for animal welfare, economics, and potential -future- alternatives.
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    Chicken or fish? Do environmental complexity and stocking density impact affective states of broiler chickens and rainbow trout?
    Anderson, Mallory G. (Virginia Tech, 2021-09-30)
    In commercial settings, broiler chickens and rainbow trout are housed in barren environments under high stocking densities, due to an emphasis on production efficiency. These monotonous housing conditions do not provide broilers or trout with the ability to perform functional, highly-motivated behaviors and increase their susceptibility to excessive anxiety and fear, resulting in negative affective states and poor animal welfare. Affective state (or emotional state) is a cumulative product of short-term life experiences, ranging from positive to negative. Because affective states are largely influenced by environmental condition, determining animal affective state can provide useful information on how to improve housing conditions in order to ensure positive experiences and good animal welfare. Cognitive processes are closely associated with affective state; a "cognitive bias" occurs when affective state influences aspects of cognition, such as judgement and attention. Animals in positive affective states make optimistically-biased decisions during ambiguous situations, judging the situation as if it will produce a positive outcome, and show less bias towards a perceived threat, responding in a less anxious and calm manner. Animals in negative affective states make pessimistically-biased decisions during ambiguous situations, judging the situation as if it will result in a negative outcome. Additionally, animals in negative affective states will bias their attention towards a perceived threat rather than alternative stimuli, responding in an anxious manner. Therefore, judgement and attention bias tests can be used to determine animal affective states. In Chapter 3, a judgement bias test was used to determine affective state of broiler chickens housed in either complex (perches, dust bath, pecking stones, and rotating enrichment objects) or barren (no enrichment) environments under either high or low stocking densities. Broilers housed in complex environments responded more optimistically during the judgement bias test than broilers from barren environments, indicating the former were in a positive affective state. Stocking density did not impact their responses in the judgement bias test, indicating that affective states were not impacted by that treatment. In Chapter 4, an attention bias test was used to determine level of anxiety and a tonic immobility test was used to determine fear in order to investigate affective state of broilers housed in the same conditions as described for Chapter 3. Broilers housed in complex environments were less anxious during the attention bias test than broilers from barren environments, indicating environmental complexity reduced anxiety in broilers. Stocking density did not impact anxiety. Broilers from high stocking density environments had shorter tonic immobility durations than broilers from low stocking density environments, suggesting the former were less fearful. Environmental complexity did not impact fearfulness. In Chapter 5, a judgement bias test was used to determine affective state of rainbow trout housed in either complex (shelter structure and artificial plants) or barren (no enrichment) tanks under either low or high stocking densities. Trout housed in high stocking density tanks responded optimistically during the judgement bias test, indicating they were in a more positive affective state compared to trout housed in low stocking density tanks. Environmental complexity did not impact their responses in the judgement bias test, indicating no effect of enrichments on affective states was found. These results indicate a beneficial relationship of a complex environment on broiler chicken affective state, observed through an optimistic judgement bias and reduced attention bias (anxiety) towards a perceived threat. Thus, providing a complex housing environment for broilers can improve their welfare and result in a positive affective state. Rainbow trout reared at the tested high density resulted in a positive affective state, although complexity did not benefit their welfare. Our results contribute much needed information on stocking densities to ensure fish welfare. Overall, environmental complexity, not stocking density, had a positive impact on broiler chicken affective states. Rainbow trout affective states were positively impacted by stocking density, but not environmental complexity.
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    Comparison of Methods for Individual Killing of Broiler Chickens: A Matter of Animal Welfare and On-Farm Feasibility
    Watteyn, Anneleen; Garmyn, An; Ampe, Bart; Jacobs, Leonie; Moons, Christel P. H.; Tuyttens, Frank A. M. (Frontiers, 2022-05-30)
    The humane killing of individual broiler chickens on-farm requires a minimum of suffering. In this regard, rapid and irreversible loss of consciousness are important determinants. This can be verified by cerebral and spinal reflexes. Also, on-farm feasibility determines whether producers will apply the method. The aim of the study was to compare the effectiveness and animal welfare impact of two different methods for killing individual broilers of varying ages (2, 4, and 6 weeks): manual cervical dislocation (CD) and captive bolt (CB). The evaluation of CD and CB was based on effectiveness and on time to onset (convulsions) or cessation (pain response, pupillary light reflex, convulsions, heartbeat) of non-invasive indicators. In addition, a pilot study was conducted on-farm to assess the feasibility of two alternative methods, CB and nitrogen gasification (N2), and to survey farmers’ opinions on them. The onset of convulsions was almost immediate for both methods in the first study. No differences between CD and CB were observed for the cessation of pain response for chickens at age of 2 weeks (5.0 and 7.5 s, respectively) and 6 weeks (14.0 and 14.1 s, respectively). However, at 4 weeks a longer pain response was measured after CD (11.3 s) than after CB (4.7 s). For the three age categories, the pupillary light reflex disappeared later after CD (54.9 - 80.7 s) compared to CB (8.3 - 13.7 s). The same was observed for cessation of convulsions in 2- and 6-week-old chickens (185.3 and 172.0 s for CD and 79.0 and 82.9 s for CB). This suggests that brain death occurred faster after CB compared to CD. No difference between the methods was found for the cessation of the heartbeat. After the pilot study, the producers preferred N2 over CB in terms of animal-friendliness, time-efficiency, ease of use, and effectiveness. However, both methods were found rather expensive and required some experience. CB and N2 are good killing alternatives to CD due to rapid and irreversible insensibility. However, more information and support for chicken producers will be needed for these to become routine killing methods.
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    Effect of Environmental Complexity and Stocking Density on Fear and Anxiety in Broiler Chickens
    Anderson, Mallory G.; Campbell, Andrew M.; Crump, Andrew; Arnott, Gareth; Newberry, Ruth C.; Jacobs, Leonie (MDPI, 2021-08-12)
    Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety) and tonic immobility (measure of fear). In Experiment 1, individual birds were tested for attention bias (n = 60) and in Experiment 2, groups of three birds were tested (n = 144). Tonic immobility testing was performed on days 12 and 26 (n = 36) in Experiment 1, and on day 19 (n = 72) in Experiment 2. In Experiment 1, no differences were observed in the attention bias test. In Experiment 2, birds from high-complexity pens began feeding faster and more birds resumed feeding than from low-complexity pens following playback of an alarm call, suggesting that birds housed in the complex environment were less anxious. Furthermore, birds housed in high-density or high-complexity pens had shorter tonic immobility durations on day 12 compared to day 26 in Experiment 1. In Experiment 2, birds from high-density pens had shorter tonic immobility durations than birds housed in low-density pens, which is contrary to expectations. Our results suggest that birds at 3 weeks of age were less fearful under high stocking density conditions than low density conditions. In addition, results indicated that the complex environment improved welfare of broilers through reduced anxiety.
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    Effect of silvopasture system on fearfulness and leg health in fast-growing broiler chickens
    Paneru, Bidur; Pent, Gabriel J.; Nastasi, Shawna; Downing, Adam K.; Munsell, John F.; Fike, John H.; Jacobs, Leonie (2023-02)
    A silvopasture system intentionally integrates trees, forages, and livestock, allowing dual land use. These systems can provide high-quality habitat for broiler chickens; however, such systems have not been widely adopted by the broiler industry in the United States. The objective of this study was to examine the effect of silvopasture versus open pasture access on fearfulness and leg health in fast-growing broiler chickens. A total of 886 mixed-sex Ross 708 chicks in Experiment 1 (Exp 1) and 648 chicks in Experiment 2 (Exp 2) were housed in coops and had access to 16 (Exp 1) or 12 (Exp 2) 125m2 silvopasture plots (x̄ = 32% canopy cover) or open pasture plots (no canopy cover) from day 24 of age. Fearfulness was measured using a tonic immobility test (tonic immobility duration), and leg health was assessed by quantifying footpad dermatitis, hock burns, gait, and performing a latency-to-lie test on days 37-39 of age. Birds in the silvopasture treatment were less fearful than birds in the open pasture treatment. Overall, birds in both silvopasture and open pasture systems had excellent leg health. Silvopasture birds had lower footpad dermatitis scores than open pasture birds. Silvopasture birds tended to have worse gait than open pasture birds in Exp 1, but not in Exp 2. Hock burn scores and latency-to-lie did not differ between treatments in Exp 1 or Exp 2. Raising birds in silvopasture reduced fear and improved footpad health compared to birds raised in open pastures, which indicates that silvopasture systems provide some benefits for affective state and leg health in fast-growing broilers.
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    Effects of Housing System on Anxiety, Chronic Stress, Fear, and Immune Function in Bovan Brown Laying Hens
    Campbell, Andrew M.; Johnson, Alexa M.; Persia, Michael E.; Jacobs, Leonie (MDPI, 2022-07-14)
    The scientific community needs objective measures to appropriately assess animal welfare. The study objective was to assess the impact of housing system on novel physiological and behavioral measurements of animal welfare for laying hens, including secretory and plasma Immunoglobulin (IgA; immune function), feather corticosterone (chronic stress), and attention bias testing (ABT; anxiety), in addition to the well-validated tonic immobility test (TI; fearfulness). To test this, 184 Bovan brown hens were housed in 28 conventional cages (3 birds/cage) and 4 enriched pens (25 birds/pen). Feces, blood, and feathers were collected 4 times between week 22 and 43 to quantify secretory and plasma IgA and feather corticosterone concentrations. TI tests and ABT were performed once. Hens that were from cages tended to show longer TI, had increased feather corticosterone, and decreased secretory IgA at 22 weeks of age. The caged hens fed quicker, and more hens fed during the ABT compared to the penned hens. Hens that were in conventional cages showed somewhat poorer welfare outcomes than the hens in enriched pens, as indicated by increased chronic stress, decreased immune function at 22 weeks of age but no other ages, somewhat increased fear, but reduced anxiety. Overall, these novel markers show some appropriate contrast between housing treatments and may be useful in an animal welfare assessment context for laying hens. More research is needed to confirm these findings.
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    Effects of Nutritional Manipulation on Poultry under Normal and Stressful Conditions
    Sarsour, Albaraa Hisham (Virginia Tech, 2021-11-01)
    Genetic selection for improved performance has necessitated the frequent update of amino acid requirements to support this improvement. The first objective of this dissertation was to investigate the tryptophan requirement of laying hens in peak production and the lysine and sulfur amino acid requirements of broiler chicks under a phase feeding scenario using different models. Digestible tryptophan requirements were estimated to be 137 for egg production, 133 for egg mass, and 133 for feed efficiency using the linear broken-line model. The lysine and sulfur amino acid requirement were estimated by conducting 3 experiments within the starter phase from 2 to 5, 5 to 8, and 8 to 11 days of age. The linear broken line estimate for digestible lysine was 1.22, 1.17 and 1.16% for BWG and 1.31, 1.21, and 1.14% for FCR in experiments 1, 2, and 3, respectively. The linear broken line estimate for sulfur amino acids was 0.82, 0.81 and 0.94% for BWG and 0.82, 0.80, and 0.90 for FCR in experiments 4, 5, and 6, respectively. The lysine requirements decreased from 2 to 5 to 8 to 11 days, however the sulfur amino acid requirements increased during that same period. This could be due to other roles that sulfur amino acids play in the body other than growth. The second objective of this dissertation was to investigate the effects of a direct fed microbial (DFM) on broilers exposed to a cyclic heat stress in 2 consecutive experiments. In this experiment, the heat stress treatment reduced body weight gain and lean tissue accretion from 0 to 35 d in both experiments. In Experiment 2, when the litter was reused BWG was increased by 36 g/bird with supplementation of DFM. Ileal digestibility at 28 d (2 hr post HS) was improved with DFM supplementation in both experiments. Serum FITC-d increased with HS at both 28 and 35 d. Serum FITC-d was generally decreased with DFM at 28 d but the response was inconsistent at 35 d. Overall, the results suggest that HS reduced broiler performance and DFM treatment improved intestinal permeability and nutrient digestibility responses to HS in both experiments but did not improve performance until built up litter was used in Experiment 2. The last objective of this dissertation was to investigate the effects of sulfur amino acids (SAA) on broilers exposed to a cyclic heat stress. As expected, HS reduced BWG and worsened FCR. The supplementation of SAA had no effect on live performance. At 28 d of age, supplementation of SAA to birds exposed to HS resulted in reduced intestinal permeability. The interaction was lost at 31 d, but HS still increased intestinal permeability (P ≤ 0.05). Potential oxidative damage was reduced by increased SAA supplementation as indicated by an increase in the reduced glutathione to oxidized glutathione ratio. These data suggest that intestinal permeability is compromised acutely to at least three days of heat exposure before the bird can adjust, but oxidative damage is more chronic building over the entire 7 d HS period. SAA might have some protective effect on both intestinal permeability and oxidative stress responses to HS.
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    Enhancing their quality of life: environmental enrichment for poultry
    Jacobs, Leonie; Blatchford, R. A.; de Jong, I. C.; Erasmus, M. A.; Levengood, M.; Newberry, R. C.; Regmi, P.; Riber, A. B.; Weimer, S. L. (Elsevier, 2023-01)
    Providing environmental enrichments that increase environmental complexity can benefit poultry welfare. This Poultry Science Association symposium paper is structured around four themes on 1) poultry preferences and affective states 2) species-specific behavior, including play behavior and the relationship between behavior, activity level and walking ability, 3) environmental enrichment and its relationship with indicators of welfare, and 4) a case study focusing on the application of enrichments in commercial broiler chicken production. For effective enrichment strategies, the birds’ perspective matters most, and we need to consider individual variation, social dynamics, and previous experience when assessing these strategies. Play behavior can be a valuable indicator of positive affect, and while we do not yet know how much play would be optimal, absence of play suggests a welfare deficit. Activity levels and behavior can be improved by environmental modifications and prior research has shown that the activity level of broilers can be increased, at least temporarily, by increasing the environmental complexity. However, more research on impacts of enrichments on birds’ resilience, on birds in commercial conditions, and on slow(er)-growing strains is needed. Finally, incorporating farmers’ expertise can greatly benefit enrichment design and implementation on commercial farms.
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    Environmental Complexity and Reduced Stocking Density Promote Positive Behavioral Outcomes in Broiler Chickens
    Evans, Lauren; Brooks, George C.; Anderson, Mallory G.; Campbell, Andrew M.; Jacobs, Leonie (MDPI, 2023-06-23)
    The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD) or low (LD) density. Through focal-animal sampling, the frequency and duration of behaviors were recorded continuously for 5 min at two timepoints for one day in weeks 2, 4, and 7. Birds were active for 30% of the observed time, with birds showing more activity in HC compared with LC. Birds in HC pens spent more time preening and foraging than birds in LC pens, which was interpreted as a positive outcome. Dustbathing and play were not impacted by complexity, possibly due to the observation method. Birds were more frequently active at HD compared with LD, but did not spend more time being active, suggesting disturbances. Birds foraged, drank, and ate less frequently in HD compared with LD, presumably because birds had more difficulty accessing resources. Activity and active behaviors reduced as birds aged, while preening frequency increased, possibly due to frustration, but this was not confirmed. Perching was unaffected by age, showing a persistent motivation to perform the behavior. Our results indicate that a complex environment provides positive stimulation for foraging, locomotion, preening, and overall activity. Despite reduced activity, many benefits of the tested environmental complexity and low density persisted as birds aged.
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    Environmental complexity positively impacts affective states of broiler chickens
    Anderson, Mallory G.; Campbell, Andrew M.; Crump, Andrew; Arnott, Gareth; Jacobs, Leonie (Nature Portfolio, 2021-08-20)
    Affective state can bias an animal’s judgement. Animals in positive affective states can interpret ambiguous cues more positively (“optimistically”) than animals in negative affective states. Thus, judgement bias tests can determine an animal’s affective state through their responses to ambiguous cues. We tested the effects of environmental complexity and stocking density on affective states of broiler chickens through a multimodal judgement bias test. Broilers were trained to approach reinforced locations signaled by one color and not to approach unreinforced locations signaled by a different color. Trained birds were tested for latencies to approach three ambiguous cues of intermediate color and location. Broilers discriminated between cues, with shorter latencies to approach ambiguous cues closest to the reinforced cue than cues closest to the unreinforced cue, validating the use of the test in this context. Broilers housed in high-complexity pens approached ambiguous cues faster than birds in low-complexity pens–an optimistic judgement bias, suggesting the former were in a more positive affective state. Broilers from high-density pens tended to approach all cues faster than birds from low-density pens, possibly because resource competition in their home pen increased food motivation. Overall, our study suggests that environmental complexity improves broilers’ affective states, implying animal welfare benefits of environmental enrichment.
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    Equipment and methods for poultry euthanasia by a single operator
    Boyal, Ranjit S.; Buhr, R. Jeff; Harris, Caitlin E.; Jacobs, Leonie; Bourassa, Dianna V. (2020-12)
    Euthanasia of large poultry can be particularly challenging due to the difficulty of manual cervical dislocation of large older birds. Euthanasia is intended to swiftly render the animal unconscious and rapidly lead to death using humane methods. Euthanasia by a single operator can be challenging when euthanizing mature broiler breeders and turkeys weighing from 4 to 30 Kg. Owing to the difficulty of manual cervical dislocation on large poultry, development and assessment of alternative methods for euthanasia are necessary. Four American Veterinary Medical Association approved alternative euthanasia methods including mechanical cervical dislocation, nonpenetrative captive bolt, carbon dioxide, and electrical euthanasia were evaluated on broiler breeders, Beltsville Small White turkeys, and Broad Breasted White turkeys. A mobile bird euthanasia apparatus was designed allowing for individual bird euthanasia by a single operator. Mechanical cervical dislocation and nonpenetrative captive bolt devices were commercially available. The carbon dioxide and electrical euthanasia devices used were developed for this work. Each of the 4 euthanasia methods were assessed for kill success defined as one euthanasia attempt with no signs of recovery. In addition, the costs associated with purchase or construction of each device are reported. All four euthanasia methods resulted in successful euthanasia of 436 birds. The overall single application euthanasia success rates were 97% for mechanical cervical dislocation, 98% for captive bolt, 97% for carbon dioxide, and 99% for electrical euthanasia. Each method can be used to successfully euthanize broiler breeders and turkeys and can be used safely when the use of manual cervical dislocation is not feasible.
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    Euthanasia for broiler chickens: manual and mechanical cervical dislocation methods
    Jacobs, Leonie; Bourassa, Dianna V.; Harris, Caitlin E.; Burr, R. Jeff (Virginia Cooperative Extension, 2019)
    For this study we evaluated the Koechner Euthanizing Device and manual cervical dislocation of 200 broiler chickens ranging from 36 to 43 days of age at scheduled flock terminations
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    Euthanasia: Manual versus Mechanical Cervical Dislocation for Broilers
    Jacobs, Leonie; Bourassa, Dianna V.; Harris, Caitlin E.; Buhr, R. Jeff (2019-02)
    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 similar to 90 degrees 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. 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 similar to 90 degrees 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.
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    Evaluation of mechanical cervical dislocation, captive bolt, carbon dioxide, and electrical methods for individual on-farm euthanasia of broiler breeders
    Boyal, R. S.; Buhr, R. J.; Harris, C. E.; Jacobs, Leonie; Bourassa, D. V. (Elsevier, 2022-09)
    Efficacious euthanasia by applying man-ual cervical dislocation can be difficult on large and mature poultry. The challenge with using manual cervical dislocation is that the strength required to hold heavy poultry and swiftly apply cervical dislocation can be phys-ically impossible for most people. Therefore, alternative methods of euthanasia are needed for mature and large poultry. Mechanical cervical dislocation using the Koech-ner Euthanizing Device (KED), captive bolt using the Turkey Euthanasia Device (TED), carbon dioxide (CO2), and electrical euthanasia were evaluated for use on 65-wk-old broiler breeders at flock termination. Fol-lowing application of each method, physiological reflexes including the eye nictitating membrane reflex, mouth gaping, and body movement, broken skin, blood loss, kill success, time to cessation of heartbeat, and blood plasma corticosterone levels were assessed. Birds euthanized using the KED had longer response durations for eye nictitating membrane (91 s) and reflexive mouth gaping (161 s) com-pared to TED, CO2, and electrical euthanasia (0-7 s). Body movement durations were also longer for KED (214 s) and TED (209 s) than for CO2 and electrical euthana-sia (0-8 s). The highest percentages of broken skin (93%) and blood loss (96%) were observed for TED, followed by KED (71%, 68%), then CO2 (0%, 6%) and electrical euthanasia (0%, 3%). No significant differences (P = 0.1781) were observed for kill success rates with 98% for KED, 100% for TED, 97% for CO2, and 100% for electri-cal euthanasia at 4-min. Time to heartbeat cessation did not differ between KED (659 s), TED (427 s), or CO2 (583 s) euthanasia methods. No heartbeat was detected following electrical euthanasia. Blood plasma corticoste-rone levels did not differ between preeuthanasia or post -euthanasia from any of the methods applied. Based on these results each euthanasia method is acceptable for use with broiler breeders.
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