{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,13]],"date-time":"2026-01-13T03:11:59Z","timestamp":1768273919525,"version":"3.49.0"},"reference-count":31,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2019,7,1]],"date-time":"2019-07-01T00:00:00Z","timestamp":1561939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Chicken Farmers of Saskatchewan, Egg Farmers of Canada, Hybrid Turkeys, Natural Sciences and Engineering Research Council (NSERC) of Canada, the Ontario Ministry of Agriculture and Rural Affairs (OMAFRA), Turkey Farmers of Canada through the Canadian Poul","award":["300-010800-052439-000000-xxxxx"],"award-info":[{"award-number":["300-010800-052439-000000-xxxxx"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>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\u201329, and 65\u201370 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 &lt; 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\u2013C2. The KED resulted in a majority of dislocations at C2\u2013C3. 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.<\/jats:p>","DOI":"10.3390\/ani9070407","type":"journal-article","created":{"date-parts":[[2019,7,1]],"date-time":"2019-07-01T10:54:47Z","timestamp":1561978487000},"page":"407","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Efficacy of a Novel Mechanical Cervical Dislocation Device in Comparison to Manual Cervical Dislocation in Layer Chickens"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7933-5185","authenticated-orcid":false,"given":"Rathnayaka M.A.S.","family":"Bandara","sequence":"first","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"},{"name":"Department of Livestock Production, Faculty of Agricultural Sciences, Sabaragamuwa University of Sri Lanka, Belihuloya 70140, Sri Lanka"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8157-9207","authenticated-orcid":false,"given":"Stephanie","family":"Torrey","sequence":"additional","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1547-0139","authenticated-orcid":false,"given":"Patricia V.","family":"Turner","sequence":"additional","affiliation":[{"name":"Department of Pathobiology, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alex zur","family":"Linden","sequence":"additional","affiliation":[{"name":"Department of Clinical Studies, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anna","family":"Bolinder","sequence":"additional","affiliation":[{"name":"Department of Animal Care Services, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karen","family":"Schwean-Lardner","sequence":"additional","affiliation":[{"name":"Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tina M.","family":"Widowski","sequence":"additional","affiliation":[{"name":"Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,7,1]]},"reference":[{"key":"ref_1","first-page":"570","article-title":"Comparison of neck dislocation and percussion of the head on visual evoked responses in the chicken\u2019s brain","volume":"126","author":"Gregory","year":"1990","journal-title":"Vet. 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