The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Philippe Gaudin - One of the best experts on this subject based on the ideXlab platform.
-
scale measurements as a conservation tool in endangered Zingel asper linnaeus 1758
Aquatic Conservation-marine and Freshwater Ecosystems, 2007Co-Authors: Delphine Danancher, Jacques Labonne, Philippe Gaudin, Pierre JolyAbstract:1. Zingel asper (a percid) is a highly endangered endemic fish of the Rhone catchment (France). Scale reading was used to estimate age and growth rates in one of the two last remaining populations that are still present in relatively high densities (River Beaume). 2. Scale reading was validated for the first time in Z. asper by comparing back-calculated lengths from scale annual increment to actual lengths obtained by individual mark–recapture monitoring. The impacts of age or sampling site on individual growth rates were explored using generalized linear models. 3. No major discrepancy was observed between actual and back-calculated lengths. Longevity of Z. asper was inferred from the age data and did not exceed 3 years. Results showed variation in growth rates among ages (20 times higher for 1+ fish than for 2+ or 3+ fish) and also among sampling sites. 4. The present work provided the first estimates of annual growth rates in the Beaume population. This study also showed that scale reading allowed a valuable trade-off between accuracy and conservation imperatives that often imply avoiding invasive techniques such as the implantation of passive integrative transponders. 5. Scale reading will be a valuable tool for future ecological studies in Z. asper and will help in developing conservation strategies for this species as longevity and growth patterns are two life-history traits of major importance for the management of endangered populations. Copyright © 2007 John Wiley & Sons, Ltd.
-
modelling population viability in fragmented environments contribution to the conservation of an endangered percid Zingel asper
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Jacques Labonne, Philippe GaudinAbstract:Zingel asper is an endemic percid of the Rhone catchment. The demography and habitat use of this endangered benthic species have been studied in previous works. The species exhibits natural low densities and clumped distribution related to habitat distribution. Based on these results, the authors build a stochastic equations network model, integrating spatial structure at intrapopulation level and vague density dependence. Calculation of density, growth rates, and local extinction rates globally match the field results. The numerical sensitivity analysis on extinction probabilities shows that adult and juvenile survival rates and spawning success (due to random events) are the key parameters of intrapatch dynamics. Low negative variations in these parameters increase extinction probabilities. The number of available connected patches and the dispersal rate drive the population persistence at the interpatch scale. Population extinction probability over 100 years is at least 0.4 for dispersal rate below 0.2...
-
Exploring population dynamics patterns in a rare fish, Zingel asper, through capture-mark-recapture methods
Conservation Biology, 2005Co-Authors: Jacques Labonne, Philippe GaudinAbstract:: We performed a capture-mark-recapture study on one of the last populations of Zingel asper, an endemic percid species of the Rhone River basin in France. The distribution of Z. asper has decreased dramatically during the last century. We sampled three sites in suitable habitats in the Beaume River. No impact of individual tagging on survival was found. The demography of the population was analyzed using capture-recapture methods that allow the estimation of survival, recruitment, and demographic growth rates. Annual survival rates were low (0.35–0.50). The level of transience was high (5% to 25%), suggesting that a significant number of individuals were highly mobile or shifted to suboptimal habitats. Seniority rates suggested random highly variable recruitment between years. The three sites had similar variation patterns in all demographic parameters, indicating broad spatial covariation in population dynamics. We found some local differences in demographic parameters, which could be linked to local habitat quality. Individual tagging allowed for the estimation of demographic parameters that improved our understanding of Z. asper population dynamics and revealed mechanisms that may affect population persistence, such as stochastic recruitment, low survival, and frequent dispersal. The fragmentation of habitat through river damming inhibits dispersal and represents a threat to the persistence of Z. asper in the Rhone basin. Our results offer evidence of the importance of dispersal in nonmigratory fishes and confirm the usefulness of individual tagging methods in rare fish demography. Resumen: Realizamos un estudio de captura-marca-recaptura en una de las ultimas poblaciones de Zingel asper, una especie de percido endemica a la cuenca del Rio Rhone en Francia. La distribucion de Z. asper ha disminuido dramaticamente durante el ultimo siglo. Muestreamos tres sitios en habitats adecuados en el Rio Beaume. No se detecto impacto del marcaje de individuos sobre la supervivencia. Analizamos la demografia de la poblacion mediante metodos de captura-recaptura que permiten la estimacion de las tasas de supervivencia, reclutamiento y crecimiento demografico. Las tasas anuales de supervivencia fueron bajas (0.35-0.5). El nivel de transitoriedad fue alto (5 a 25%), lo que sugiere que un numero significativo de individuos tuvo mucha movilidad o se cambio a habitats suboptimos. Las tasas de veterania sugirieron reclutamiento aleatorio muy variable entre anos. Los tres sitios tuvieron patrones de variacion similares en todos los parametros demograficos, lo que indica amplia covariacion espacial en la dinamica poblacional. Encontramos algunas diferencias locales en parametros demograficos, que pueden estar relacionados con la calidad del habitat local. El marcaje individual permitio la estimacion de parametros demograficos que mejoraron nuestro entendimiento de la dinamica poblacional de Z. asper y revelo mecanismos que pueden afectar la persistencia de la poblacion, como el reclutamiento estocastico, baja supervivencia y dispersion frecuente. La fragmentacion del habitat, mediante presas, inhibe la dispersion y representa una amenaza a la persistencia de Z. asper en la cuenca del Rhone. Nuestros resultados proporcionan evidencia de la importancia de la dispersion en peces no migratorios y confirma la utilidad de los metodos de marcaje individual en la demografia de peces raros.
-
capture recapture estimates of space used in streams cresus at the population scale case study on Zingel asper percid a threatened species of the rhone catchment
Canadian Journal of Fisheries and Aquatic Sciences, 2004Co-Authors: Delphine Danancher, Jacques Labonne, Roger Pradel, Philippe GaudinAbstract:In this study, capturemarkrecapture statistics were applied to spatial recapture histories to assess the intensity of fish restricted movements along the longitudinal axis of a river using a previously described model for survival and recruitment analysis. Adapting the stopover estimation method to spatial data, movement probabilities were then used to estimate space used at the population scale. This capturerecapture estimates of space used in streams (CRESUS) method may thus be seen as a complementary tool of classic home range methods and should be used to explore the consequence of behavioural strategies on population mechanisms. We propose a methodological example where movements and space use strategies of a Zingel asper (percid) population in the Beaume River (Ardeche, France) were directly estimated at the population scale taking account of the effects of different biotic or abiotic factors. Results showed differences in Z. asper space use patterns among sexes, periods of biological cycle (grow...
-
use of a generalised linear model to test habitat preferences the example of Zingel asper an endemic endangered percid of the river rhone
Freshwater Biology, 2003Co-Authors: Jacques Labonne, Stephanie Allouche, Philippe GaudinAbstract:SUMMARY 1. A study of microhabitat preferences was conducted on Zingel asper, an endangered endemic species from the Rhone catchment. A generalised linear model allowed us to test statistically the non-random habitat selection and the effect of season and site on this habitat selection. 2. The analysis detected significant preferences for the three physical variables considered: water depth, water velocity and substratum size. 3. A seasonal shift in the substratum size preference was found: preference for stones increasing during the spawning season. Depth preference varied between sites, suggesting a possible plasticity in habitat selection. 4. These results suggest that the availability of suitable physical habitat plays a significant role in determining fish distribution in the River Beaume.
Delphine Danancher - One of the best experts on this subject based on the ideXlab platform.
-
Development of 55 novel polymorphic microsatellite loci for the critically endangered Zingel asper L. (Actinopterygii: Perciformes: Percidae) and cross-species amplification in five other percids
European Journal of Wildlife Research, 2010Co-Authors: Vincent Dubut, Rémi Chappaz, Rémi Grenier, Emese Meglécz, Caroline Costedoat, Delphine Danancher, Stéphane Descloux, Thibaut Malausa, Jean-françois Martin, Nicolas PechAbstract:By combining biotin-enrichment protocol and next generation pyrosequencing, through 454 GS-FLX Titanium technology, 55 polymorphic microsatellites loci with perfect motif were isolated from the Rhone streber ( Zingel asper ), a critically endangered European fish species. Eight multiplex PCR kits were optimised in order to genotype a total of 58 polymorphic loci, including three previously published loci. The level of genetic diversity was assessed for 68 Z. asper , 30 Sander lucioperca , 33 Perca fluviatilis and four Gymnocephalus schraetzer individuals. Amplification success was also assessed on Romanichthys valsanicola and Zingel streber using single individuals. These markers will be useful to investigate the population structure of the highly fragmented Rhone streber. They represent a powerful tool for conservation issues and evolutionary approaches of this endemic species. Moreover, part of our markers demonstrated applicability to other percid species, allowing for potential applications to fisheries and aquaculture management.
-
microsatellite analysis of relatedness structure in young of the year of the endangered Zingel asper percidae and implications for conservation
Freshwater Biology, 2008Co-Authors: Delphine Danancher, J I Izquierdo, Eva GarciavazquezAbstract:Summary 1. Zingel asper is one of the most endangered freshwater fish of Western Europe. Because of critical habitat loss and fragmentation, stocking or reintroduction protocols are sometimes considered even though few data are available about the behaviour and biology of the species. 2. The present study is the first attempt to explore the population genetic structure of juveniles (young of the year, YOY) of this endangered species using genetic markers (microsatellite loci). In the Beaume River (ardeche, France), Z. asper exhibits very low densities (10–80 fish per hectare), and it was expected that annual recruitment would comprise only few clutches (full- or half-sibs groups). 3. However, sibship reconstruction in one YOY cohort showed that more than 60% of the adult population reproduced. Dispersal rate in early YOY was high: relatedness estimates showed that only few months after hatching, YOY sibs were mixed among study sites. A large number of breeders together with high dispersal rates explain the high genetic variability observed in small populations of Z. asper. 4. Conservation strategies for the species are discussed based on these results, emphasizing the importance of conserving population genetic variability and preserving habitat connectivity for juveniles.
-
scale measurements as a conservation tool in endangered Zingel asper linnaeus 1758
Aquatic Conservation-marine and Freshwater Ecosystems, 2007Co-Authors: Delphine Danancher, Jacques Labonne, Philippe Gaudin, Pierre JolyAbstract:1. Zingel asper (a percid) is a highly endangered endemic fish of the Rhone catchment (France). Scale reading was used to estimate age and growth rates in one of the two last remaining populations that are still present in relatively high densities (River Beaume). 2. Scale reading was validated for the first time in Z. asper by comparing back-calculated lengths from scale annual increment to actual lengths obtained by individual mark–recapture monitoring. The impacts of age or sampling site on individual growth rates were explored using generalized linear models. 3. No major discrepancy was observed between actual and back-calculated lengths. Longevity of Z. asper was inferred from the age data and did not exceed 3 years. Results showed variation in growth rates among ages (20 times higher for 1+ fish than for 2+ or 3+ fish) and also among sampling sites. 4. The present work provided the first estimates of annual growth rates in the Beaume population. This study also showed that scale reading allowed a valuable trade-off between accuracy and conservation imperatives that often imply avoiding invasive techniques such as the implantation of passive integrative transponders. 5. Scale reading will be a valuable tool for future ecological studies in Z. asper and will help in developing conservation strategies for this species as longevity and growth patterns are two life-history traits of major importance for the management of endangered populations. Copyright © 2007 John Wiley & Sons, Ltd.
-
apports de l ecologie comportementale a la conservation d un poisson en voie de disparition l apron du rhone Zingel asper
2005Co-Authors: Delphine DanancherAbstract:L'apron (Zingel Asper), poisson endemiquedu bassin du Rhone, est menace de disparition. L'adaptation des modeles de capture-marquage-recapture (CMR) a l'etude de ses preferences de micro et de meso-habitat (facies) ainsi que les travaux de genetique (relations d'apparentement, dispersion juvenile) ont revele l'importance des deplacements, de l'heterogeneite spatiale des habitats et du systeme d'appariement dans le maintien d'une des dernieres populations viable d'apron (riviere Beaume, Ardeche). Le protocole de CMR a egalement permis l'estimation des rythmes de croissance et leur validation. Les resultats acquis au cours de ce travail ont ete discutes en fonction des perspectives de conservation de l'espece
-
capture recapture estimates of space used in streams cresus at the population scale case study on Zingel asper percid a threatened species of the rhone catchment
Canadian Journal of Fisheries and Aquatic Sciences, 2004Co-Authors: Delphine Danancher, Jacques Labonne, Roger Pradel, Philippe GaudinAbstract:In this study, capturemarkrecapture statistics were applied to spatial recapture histories to assess the intensity of fish restricted movements along the longitudinal axis of a river using a previously described model for survival and recruitment analysis. Adapting the stopover estimation method to spatial data, movement probabilities were then used to estimate space used at the population scale. This capturerecapture estimates of space used in streams (CRESUS) method may thus be seen as a complementary tool of classic home range methods and should be used to explore the consequence of behavioural strategies on population mechanisms. We propose a methodological example where movements and space use strategies of a Zingel asper (percid) population in the Beaume River (Ardeche, France) were directly estimated at the population scale taking account of the effects of different biotic or abiotic factors. Results showed differences in Z. asper space use patterns among sexes, periods of biological cycle (grow...
Jacques Labonne - One of the best experts on this subject based on the ideXlab platform.
-
scale measurements as a conservation tool in endangered Zingel asper linnaeus 1758
Aquatic Conservation-marine and Freshwater Ecosystems, 2007Co-Authors: Delphine Danancher, Jacques Labonne, Philippe Gaudin, Pierre JolyAbstract:1. Zingel asper (a percid) is a highly endangered endemic fish of the Rhone catchment (France). Scale reading was used to estimate age and growth rates in one of the two last remaining populations that are still present in relatively high densities (River Beaume). 2. Scale reading was validated for the first time in Z. asper by comparing back-calculated lengths from scale annual increment to actual lengths obtained by individual mark–recapture monitoring. The impacts of age or sampling site on individual growth rates were explored using generalized linear models. 3. No major discrepancy was observed between actual and back-calculated lengths. Longevity of Z. asper was inferred from the age data and did not exceed 3 years. Results showed variation in growth rates among ages (20 times higher for 1+ fish than for 2+ or 3+ fish) and also among sampling sites. 4. The present work provided the first estimates of annual growth rates in the Beaume population. This study also showed that scale reading allowed a valuable trade-off between accuracy and conservation imperatives that often imply avoiding invasive techniques such as the implantation of passive integrative transponders. 5. Scale reading will be a valuable tool for future ecological studies in Z. asper and will help in developing conservation strategies for this species as longevity and growth patterns are two life-history traits of major importance for the management of endangered populations. Copyright © 2007 John Wiley & Sons, Ltd.
-
modelling population viability in fragmented environments contribution to the conservation of an endangered percid Zingel asper
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Jacques Labonne, Philippe GaudinAbstract:Zingel asper is an endemic percid of the Rhone catchment. The demography and habitat use of this endangered benthic species have been studied in previous works. The species exhibits natural low densities and clumped distribution related to habitat distribution. Based on these results, the authors build a stochastic equations network model, integrating spatial structure at intrapopulation level and vague density dependence. Calculation of density, growth rates, and local extinction rates globally match the field results. The numerical sensitivity analysis on extinction probabilities shows that adult and juvenile survival rates and spawning success (due to random events) are the key parameters of intrapatch dynamics. Low negative variations in these parameters increase extinction probabilities. The number of available connected patches and the dispersal rate drive the population persistence at the interpatch scale. Population extinction probability over 100 years is at least 0.4 for dispersal rate below 0.2...
-
Exploring population dynamics patterns in a rare fish, Zingel asper, through capture-mark-recapture methods
Conservation Biology, 2005Co-Authors: Jacques Labonne, Philippe GaudinAbstract:: We performed a capture-mark-recapture study on one of the last populations of Zingel asper, an endemic percid species of the Rhone River basin in France. The distribution of Z. asper has decreased dramatically during the last century. We sampled three sites in suitable habitats in the Beaume River. No impact of individual tagging on survival was found. The demography of the population was analyzed using capture-recapture methods that allow the estimation of survival, recruitment, and demographic growth rates. Annual survival rates were low (0.35–0.50). The level of transience was high (5% to 25%), suggesting that a significant number of individuals were highly mobile or shifted to suboptimal habitats. Seniority rates suggested random highly variable recruitment between years. The three sites had similar variation patterns in all demographic parameters, indicating broad spatial covariation in population dynamics. We found some local differences in demographic parameters, which could be linked to local habitat quality. Individual tagging allowed for the estimation of demographic parameters that improved our understanding of Z. asper population dynamics and revealed mechanisms that may affect population persistence, such as stochastic recruitment, low survival, and frequent dispersal. The fragmentation of habitat through river damming inhibits dispersal and represents a threat to the persistence of Z. asper in the Rhone basin. Our results offer evidence of the importance of dispersal in nonmigratory fishes and confirm the usefulness of individual tagging methods in rare fish demography. Resumen: Realizamos un estudio de captura-marca-recaptura en una de las ultimas poblaciones de Zingel asper, una especie de percido endemica a la cuenca del Rio Rhone en Francia. La distribucion de Z. asper ha disminuido dramaticamente durante el ultimo siglo. Muestreamos tres sitios en habitats adecuados en el Rio Beaume. No se detecto impacto del marcaje de individuos sobre la supervivencia. Analizamos la demografia de la poblacion mediante metodos de captura-recaptura que permiten la estimacion de las tasas de supervivencia, reclutamiento y crecimiento demografico. Las tasas anuales de supervivencia fueron bajas (0.35-0.5). El nivel de transitoriedad fue alto (5 a 25%), lo que sugiere que un numero significativo de individuos tuvo mucha movilidad o se cambio a habitats suboptimos. Las tasas de veterania sugirieron reclutamiento aleatorio muy variable entre anos. Los tres sitios tuvieron patrones de variacion similares en todos los parametros demograficos, lo que indica amplia covariacion espacial en la dinamica poblacional. Encontramos algunas diferencias locales en parametros demograficos, que pueden estar relacionados con la calidad del habitat local. El marcaje individual permitio la estimacion de parametros demograficos que mejoraron nuestro entendimiento de la dinamica poblacional de Z. asper y revelo mecanismos que pueden afectar la persistencia de la poblacion, como el reclutamiento estocastico, baja supervivencia y dispersion frecuente. La fragmentacion del habitat, mediante presas, inhibe la dispersion y representa una amenaza a la persistencia de Z. asper en la cuenca del Rhone. Nuestros resultados proporcionan evidencia de la importancia de la dispersion en peces no migratorios y confirma la utilidad de los metodos de marcaje individual en la demografia de peces raros.
-
capture recapture estimates of space used in streams cresus at the population scale case study on Zingel asper percid a threatened species of the rhone catchment
Canadian Journal of Fisheries and Aquatic Sciences, 2004Co-Authors: Delphine Danancher, Jacques Labonne, Roger Pradel, Philippe GaudinAbstract:In this study, capturemarkrecapture statistics were applied to spatial recapture histories to assess the intensity of fish restricted movements along the longitudinal axis of a river using a previously described model for survival and recruitment analysis. Adapting the stopover estimation method to spatial data, movement probabilities were then used to estimate space used at the population scale. This capturerecapture estimates of space used in streams (CRESUS) method may thus be seen as a complementary tool of classic home range methods and should be used to explore the consequence of behavioural strategies on population mechanisms. We propose a methodological example where movements and space use strategies of a Zingel asper (percid) population in the Beaume River (Ardeche, France) were directly estimated at the population scale taking account of the effects of different biotic or abiotic factors. Results showed differences in Z. asper space use patterns among sexes, periods of biological cycle (grow...
-
use of a generalised linear model to test habitat preferences the example of Zingel asper an endemic endangered percid of the river rhone
Freshwater Biology, 2003Co-Authors: Jacques Labonne, Stephanie Allouche, Philippe GaudinAbstract:SUMMARY 1. A study of microhabitat preferences was conducted on Zingel asper, an endangered endemic species from the Rhone catchment. A generalised linear model allowed us to test statistically the non-random habitat selection and the effect of season and site on this habitat selection. 2. The analysis detected significant preferences for the three physical variables considered: water depth, water velocity and substratum size. 3. A seasonal shift in the substratum size preference was found: preference for stones increasing during the spawning season. Depth preference varied between sites, suggesting a possible plasticity in habitat selection. 4. These results suggest that the availability of suitable physical habitat plays a significant role in determining fish distribution in the River Beaume.
Jeandominique Durand - One of the best experts on this subject based on the ideXlab platform.
-
genetic structure of fragmented populations of a threatened endemic percid of the rhone river Zingel asper
Heredity, 2004Co-Authors: Jean Laroche, Jeandominique DurandAbstract:Zingel asper is an endemic percid of the Rhone basin considered to be critically endangered. This species was continuously distributed throughout the Rhone in 1900, but today only occupies 17% of its initial area. In the present study, five microsatellite loci were used to assess the level of genetic variability within and among populations localized in different sub-basins. Contrasting results were obtained for the three main populations from the Rhone. A reduced allelic diversity was observed for the two populations displaying the lowest patch sizes (length of the river system occupied); of these, a recent genetic bottleneck was detected for the population showing a particularly low density. However, the third population was characterized by a relatively large spatial extent, high local fish concentrations and an allelic diversity that was twice as high and associated with an equilibrium between mutation and drift. Thus, this population shows an apparently better evolutionary potential for long-term survival. Since 1930, a marked fragmentation of the whole Rhone system has appeared, related to the development of dams, and we assume that the significant genetic differentiation detected between the populations could mainly reflect the impact of this fragmentation. The high turnover of the Z. asper populations, and the major role of dispersal in population persistence (highlighted in a recent population dynamics study), indeed suggest that the differentiation observed could mainly have arisen from habitat fragmentation in recent history.
Victoria Sandilands - One of the best experts on this subject based on the ideXlab platform.
-
Welfare assessment of novel on-farm killing methods for poultry - Fig 8
2019Co-Authors: Jessica E. Martin, Victoria Sandilands, Julian Sparrey, Laurence Baker, Laura M. Dixon, Dorothy E. F. MckeeganAbstract:Summaries of the mean maximum durations (±SE) (s) across the three kill treatments (Modified Armadillo (MARM); novel mechanical cervical dislocation (NMCD); Modified Zinger (MZIN) and manual cervical dislocation (MCD)) for the cranial reflexes: (a) jaw tone; (b) nictitating membrane; (c) pupillary reflex; and (d) rhythmic breathing. No common superscript indicates that there is a significant difference between the treatment groups.
-
Mean (±SE) age and weight at time of killing for each bird type and age group, as well as numbers of birds allocated to each killing treatment (Modified Armadillo (MARM); Modified Zinger (MZIN); novel mechanical cervical dislocation (NMCD) and manual
2019Co-Authors: Jessica E. Martin, Victoria Sandilands, Julian Sparrey, Laurence Baker, Laura M. Dixon, Dorothy E. F. MckeeganAbstract:Mean (±SE) age and weight at time of killing for each bird type and age group, as well as numbers of birds allocated to each killing treatment (Modified Armadillo (MARM); Modified Zinger (MZIN); novel mechanical cervical dislocation (NMCD) and manual cervical dislocation (MCD).
-
Summary statistics (mean, SE, minimum, and maximum) of behavioural/reflex durations post killing treatment application, as well as statistical differences (F statistic and p value) dependent on killing treatment (Modified Armadillo (MARM); novel mech
2019Co-Authors: Jessica E. Martin, Victoria Sandilands, Julian Sparrey, Laurence Baker, Laura M. Dixon, Dorothy E. F. MckeeganAbstract:Summary statistics (mean, SE, minimum, and maximum) of behavioural/reflex durations post killing treatment application, as well as statistical differences (F statistic and p value) dependent on killing treatment (Modified Armadillo (MARM); novel mechanical cervical dislocation (NMCD); Modified Zinger (MZIN) and manual cervical dislocation (MCD)).
-
Comparison of novel mechanical cervical dislocation and a modified captive bolt for on-farm killing of poultry on behavioural reflex responses and anatomical pathology
Animal Welfare, 2016Co-Authors: Jessica Martin, Dorothy E. F. Mckeegan, Julian Sparrey, Victoria SandilandsAbstract:An alternative emergency method for killing poultry on-farm is required following European legislation changes (EU 1099/2009), which heavily restricts the use of manual cervical dislocation. This study investigated the kill efficacy of two mechanical methods that conform to the new legislation: (i) a novel mechanical cervical dislocation device; and (ii) a modified captive-bolt device (Rabbit Zinger™) and manual cervical dislocation (the control). Killing treatments were applied to broilers and layers at two stages of production (broilers: 2–3 and 5 weeks of age; layers: 12–13 and 58–62 weeks), with a total of 180 birds. Latency to abolition of cranial and behavioural reflexes, as well as post mortem analysis of the physiological damage produced, were used to estimate time to unconsciousness and assess kill efficacy. The novel mechanical cervical dislocation device was reliable and a practical method for killing poultry on-farm (100% kill success), with the majority of cranial reflexes showing no significant differences between interval mean durations across killing methods (eg nictitating membrane [mean = 0.7–3.3 s], and rhythmic breathing [mean = 0.0–0.3 s]), however for jaw tone and pupillary reflex, the modified Rabbit Zinger™ had significantly shorter interval mean durations compared to the control and mechanical cervical dislocation device (mean differences: jaw tone = ∼8 s; pupillary = ∼38 s). The novel mechanical cervical dislocation device resulted in consistent anatomical damage to the birds (eg high dislocation of the neck and severing of the spinal cord) compared to the manual method, despite both having 100% success rate, while the modified Rabbit Zinger™ was difficult to operate and resulted in varied anatomical damage. The novel mechanical cervical dislocation device showed promise as a replacement kill method on-farm for poultry.
