Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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    Review: Space allowance for growing pigs: animal welfare, performance and on-farm practicality
    (Elsevier B V on behalf of The Animal Consortium, 2024-06) Chidgey KL
    There is considerable variation in the recommended minimum space allowance for growing pigs in scientific literature, and growing pressure, arising from recent reviews of current animal welfare standards for pigs, to increase the minimum space allowances set in legislation in some countries (e.g., European Union countries and New Zealand). The space provided for growing pigs needs to accommodate their physical body size in addition to social behaviour, activity, and essential functional behaviours. However, recommended minimum space allowances vary according to criteria such as temperature, live weight, flooring type, group size, behaviour, and enrichment availability. Though there may be justification for increasing current space requirements, this will present a practical issue on existing farms and could even result in unintended negative welfare outcomes, depending on how farmers address an increased requirement for space. This is not helped by inconsistent scientific approaches to assessing the effect of space on pig performance, and a lack of information on how space allowance impacts a pig's affective state. This review explores the scientific basis of the most common approaches to determining minimum space allowances for growing pigs and discusses the various factors that influence and interact with their spatial requirements. Consideration is given to their nutrition, physical environment, health, and behaviour to understand the welfare, performance, and practicality implications of differing recommendations for space allowance. More research is needed that investigates a range of space allowances to better understand the relationship between animal welfare and performance outcomes, and space allowance. This must replicate commercial conditions so that recommendations are relevant, future-focused, and achieve positive welfare outcomes in a practical but meaningful manner.
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    Ethological and procedural assessment of ballistics euthanasia for stranded cetaceans
    (Elsevier B.V., 2025-02-12) Boys RM; Beausoleil NJ; Stockin KA
    Euthanasia may be necessary at cetacean stranding events to end suffering. To ensure a humane death, verification of unconsciousness must be undertaken following application of the killing method. However, only limited information is reported on individual euthanasia events, including how unconsciousness and/or death is assessed. Here, we describe current practices for euthanising stranded cetaceans in New Zealand by analysing video footage of fourteen ballistics events involving various species. Specifically, we detail the ballistics procedures applied and the behavioural responses of the animals. Additionally, we sought to understand how animal unconsciousness was evaluated following each event by surveying the personnel involved. Video recordings ranged in length from 25 to 480 s after the initial shot and involved 14 cetaceans: one Cuvier's beaked whale, one pygmy sperm whale, one bottlenose dolphin, four pilot whales and seven false killer whales. Unconsciousness criteria were typically not observed being verified in the videos analysed, despite markspersons stating that death occurred in < 1 minute for most animals. Number of shots applied to an animal ranged from 1–3. Key behaviours indicative of unconsciousness included a continuously slack lower jaw and epaxial muscle relaxation. Based on behavioural observations, 66.7 % of animals for which an estimate could be made (n = 12) were likely unconscious within 30 s of the initial shot; half of these were likely unconscious within 10 s. The remaining animals appeared conscious for 30 s after the initial shot, and half of these were likely still conscious after one minute. Ten animals displayed post-shot behaviours suggestive of voluntary control, including tail lifting, beyond the point of presumed death reported by markspersons. The lack of verification of unconsciousness in most animals (12/14) hinders our ability to understand how these behaviours may correlate with awareness and thus welfare impacts of shooting. While the application of ballistics appeared to follow current national recommendations, mandated procedures for verifying death were rarely observed. We recommend exploring the reasons for this finding, to ensure that such procedures are appropriately undertaken, and welfare compromise minimised.
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    Evaluation of ballistics euthanasia applied to stranded cetaceans using ethological and post-mortem computed tomography assessment
    (Springer Nature, 2024-09-17) Boys RM; Kot BCW; Lye G; Beausoleil NJ; Hunter S; Stockin KA
    Debilitated stranded cetaceans with low survival likelihood, may require euthanasia to avoid further suffering. Euthanasia can involve chemical or physical methods, including ballistics. Ballistics should cause instantaneous, permanent insensibility through brainstem disruption. Despite wide application, there is limited understanding of ballistics-related welfare outcomes. We opportunistically examined behaviour of three maternally-dependent cetaceans following shooting and the related cranial disruption post-mortem using computed tomography (PMCT). Our aim was to understand whether a 'humane death', i.e., euthanasia, was achieved. Each animal was shot using different projectile types: soft non-bonded, solid, and soft bonded. In two animals, insensibility was not immediately assessed following shooting, although both were reported as 'instantaneously insensible'. From our analysis, all animals displayed musculoskeletal responses to shooting, including peduncle stiffening and slack lower jaw, followed by musculature relaxation 24-, 10.3- and 20.8-seconds post-ballistics, respectively. The animal shot with a soft non-bonded projectile also displayed agonal convulsions and tail-lifting for 16-seconds post-shot; these were not observed for solid or soft bonded projectiles. PMCT findings indicated projectile disruption to the brainstem and/or spinal cord likely to cause near-instantaneous insensibility. However, extra-cranial wounding was also evident for the soft non-bonded projectile, highlighting potential for additional welfare compromise. Our results demonstrate that ballistics can achieve a relatively rapid death in young, stranded cetaceans, but careful equipment selection is required. To ensure a humane death, verification of insensibility must be undertaken immediately following shooting. Further studies should be undertaken to improve knowledge of appropriate procedures and equipment for euthanasia, ensuring humane deaths for compromised cetaceans.
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    Evaluation of insensibility in humane slaughter of teleost fish including the use of electroencephalogram with a case study on farmed barramundi (Lates calcarifer)
    (Elsevier B V, 2024-09-15) Wahltinez SJ; Cohen S; Hardy-Smith P; Huynh C; Kells N
    Humane slaughter methods for fish are an important facet of responsible farming practice that can both minimise animal distress and improve product quality. In addition, consumers are increasingly demanding good welfare across all phases of farmed animal production, including at slaughter. As a result, many intergovernmental organisations, government bodies, and third-party certification schemes now include fish slaughter practices in their legislation, guidelines, and audit schemes. In order to be considered humane, slaughter methods should not be aversive to the fish and should result in rapid insensibility without recovery of consciousness prior to death. Where the act of slaughter does not cause immediate loss of sensibility, this should be preceded by an effective stunning method that induces rapid insensibility that is maintained until death. However, determining when fish are insensible is challenging. The effective evaluation of insensibility and stunning is important to prevent any suffering or distress that might occur when invasive killing methods, such as bleeding or evisceration, are used. Insensibility may be assessed using observable indicators such as fish behaviour, or objectively through measuring brain activity using electroencephalography. There is concern that observable indicators, such as opercular movement, righting responses, and spontaneous movement, may not be reliable signs of insensibility. It is therefore important to validate these observable indicators using objective measures, which can determine when electrical changes in the brain occur that indicate insensibility. Barramundi (Lates calcarifer) are an important aquaculture species that are farmed worldwide. Currently, this species is usually slaughtered by ice slurry immersion, a practice which has raised welfare concerns in other fish species. The objectives of this review are to provide background on current slaughter methods used for teleost fish, to summarise the methods used to evaluate insensibility in fish at stunning and slaughter, and to describe the current practices and future directions for the slaughter of farmed barramundi.