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Clemente GA, Tolini C, Boscarino A, Lorenzi V, Dal Lago TL, Benedetti D, Bellucci F, Manfrin A, Trocino A, Rota Nodari S. Farmed fish welfare during slaughter in Italy: survey on stunning and killing methods and indicators of unconsciousness. Front Vet Sci 2023; 10:1253151. [PMID: 37869496 PMCID: PMC10585058 DOI: 10.3389/fvets.2023.1253151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 08/29/2023] [Indexed: 10/24/2023] Open
Abstract
Information on slaughter procedures for farmed fish in aquaculture is limited, both in Europe and in Italy, due to a general lack of field data. The aim of this study was to gather information on the procedures used to slaughter fish in Italy and to discuss them considering the WOAH and EFSA recommendations on fish welfare. Using a questionnaire survey, data were collected by official veterinarians in 64 slaughtering facilities where 20 different species of fish were slaughtered. The main species slaughtered were rainbow trout (Oncorhynchus mykiss; 29/64), followed by European sea bass (Dicentrarchus labrax; 21/64), sea bream (Sparus aurata; 21/64), Arctic char (Salvelinus alpinus; 14/64), European eel (Anguilla anguilla; 11/64), sturgeon (Acipenser spp; 11/64), common carp (Cyprinus carpio; 6/64), and brown trout (Salmo trutta fario L.; 5/64). The most applied stunning/killing methods were "asphyxia in ice/thermal shock" and "electric in water bath," followed by "percussion," "asphyxia in air," and "electric dry system." After the application of the method, the assessment of the fish level of unconsciousness was practiced in 72% of the facilities using more than one indicator, with "breathing" and "coordinated movements" the most practiced. The collected data showed a discrepancy between the available recommendations about the welfare of fish at slaughter and what is practiced in many production sites, but for many species precise recommendations are still not available.
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Affiliation(s)
- Gianfilippo Alessio Clemente
- Italian National Reference Center for Animal Welfare, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna ‘Bruno Ubertini’, Brescia, Italy
| | - Clara Tolini
- Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna ‘Bruno Ubertini’, Brescia, Italy
| | - Andrea Boscarino
- Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna ‘Bruno Ubertini’, Brescia, Italy
| | - Valentina Lorenzi
- Italian National Reference Center for Animal Welfare, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna ‘Bruno Ubertini’, Brescia, Italy
| | | | | | | | - Amedeo Manfrin
- National Reference Laboratory for Crustacean Diseases, Istituto Zooprofilattico Sperimentale della Venezie, Legnaro, Italy
| | - Angela Trocino
- Department of Agronomy, Food Natural Resources Animals Environment, University of Padua, Legnaro, Italy
- Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro, Italy
| | - Sara Rota Nodari
- Italian National Reference Center for Animal Welfare, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna ‘Bruno Ubertini’, Brescia, Italy
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Mocho JP, von Krogh K. A FELASA Working Group Survey on Fish Species Used for Research, Methods of Euthanasia, Health Monitoring, and Biosecurity in Europe, North America, and Oceania. BIOLOGY 2022; 11:biology11091259. [PMID: 36138738 PMCID: PMC9495953 DOI: 10.3390/biology11091259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 11/20/2022]
Abstract
Simple Summary An international survey was conducted regarding species used for research, methods of euthanasia, health monitoring, and biosecurity in fish laboratories. A total of 145 facilities from 23 countries contributed. Over 80 different species were reported to be used for research, of which zebrafish (Danio rerio) was the most common by far. Anesthetic overdose was the preferred method for euthanasia for adults, fry, and larvae not capable of independent feeding. For all developmental stages, the most popular anesthetic compound was tricaine. Around half of the respondents did not perform a completion method to ensure death. One-quarter of the responding facilities did not have a health monitoring system in place. Only a small fraction reported quarantine routines to ensure reliable biological barriers. There was little consensus amongst facilities in how to perform biosecurity measures. Abstract An international survey was conducted regarding species used for research, methods of euthanasia, health monitoring, and biosecurity in fish laboratories. A total of 145 facilities from 23 countries contributed. Collectively, over 80 different species (or groups of species) were reported to be used for research, of which zebrafish (Danio rerio) was the most common by far. About half of the participating laboratories used multiple species. Anesthetic overdose was the preferred method for euthanasia for adult, fry (capable of independent feeding), and larval (not capable of independent feeding) fish. For all developmental stages, the most popular anesthetic compound was tricaine (MS-222), a substance associated with distress and aversion in several species. Moreover, around half of the respondents did not perform a completion method to ensure death. One-quarter of the responding facilities did not have a health monitoring system in place. While most respondents had some form of quarantine process for imported fish, only a small fraction reported quarantine routines that ensure reliable biological barriers. Furthermore, less than one in five screened fish for pathogens while in quarantine. In sum, there was little consensus amongst facilities in how to perform biosecurity measures. Regarding euthanasia, health monitoring, and biosecurity processes, there is a need for updated and universal guidelines and for many laboratories to adjust their practices.
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Jung-Schroers V, Hildebrandt U, Retter K, Esser KH, Hellmann J, Kleingeld DW, Rohn K, Steinhagen D. Is humane slaughtering of rainbow trout achieved in conventional production chains in Germany? Results of a pilot field and laboratory study. BMC Vet Res 2020; 16:197. [PMID: 32539725 PMCID: PMC7296641 DOI: 10.1186/s12917-020-02412-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 06/04/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rainbow trout, Oncorhynchus mykiss, is an important fish in European freshwater aquaculture. This industry sector is dominated by small family-owned enterprises located in rural areas. A large percentage of rainbow trout produced by these small enterprises is marketed directly and killed on demand and not processed in commercial processing plants. EU and national regulations stipulate that fish shall be stunned prior to killing and slaughter. The overall objective of this study was to monitor how stunning interventions were integrated into the production chains of German conventional trout aquaculture in order to safeguard animal welfare during stunning and killing. For this, the stunning and slaughtering processes were monitored on 18 rainbow trout farms in various German federal states. During the on-farm research, (i) the stunning success, (ii) injuries related to the stunning procedure, (iii) duration between stunning and killing, and (iv) visible responses at the time of slaughtering were assessed as welfare indicators. In addition, haematological and biochemical blood parameters were measured as indicators for physiological stress. Due to the fact that stunning interventions should induce a loss of consciousness in fish, in a laboratory study, it was examined whether the absence of the brainstem/ behavioural responses, opercular movements (OM) or eye-rolling reflex (vestibulo-ocular reflex, VOR) was correlated with the stage of insensibility. RESULTS The majority of rainbow trout farms applied manual percussion (38%) or electrical stunning (48%), while on 14% of the farms, the fish were stunned by electrical stunning which was immediately followed by manual percussion. After percussive stunning, about 92.3% of the rainbow trout displayed no OM or VOR as brainstem/ behavioural indicators of consciousness. This percentage varied on farms which applied electrical stunning. While on the majority of farms, 95 to 100% of the fish were unconscious according to the observation of brainstem/ behavioural indicators, the stunning intervention was less effective on farms where rainbow trout were stunned at current densities below 0.1 A dm2 or for a few seconds only. The laboratory study confirmed that the absence of brainstem/ behavioural indicators correlated with the absence of visually evoked responses (VER) of the brain to light stimuli as a neuronal indicator of insensibility. Therefore, the brainstem/ behavioural signs can be used to interpret the stage of insensibility in rainbow trout. A stage of insensibility could safely be induced by exposing portion-sized rainbow trout to an electric current density above 0.1 A dm2. This was not influenced by the orientation of the electric field. CONCLUSIONS In conventional aquaculture, rainbow trout can effectively be stunned by manual percussion or electrical stunning. Consciousness can be monitored by the absence of opercular movements or the eye-rolling reflex, which are lost approximately at the same time as neurological responses like VER. For safeguarding animal welfare during stunning and killing of rainbow trout in conventional production processes, the stunning process requires careful attention and the operating personnel need to be trained in using the stunning devices and recognising indicators of consciousness.
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Affiliation(s)
- Verena Jung-Schroers
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559, Hannover, Germany
| | - Uta Hildebrandt
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559, Hannover, Germany
| | - Karina Retter
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559, Hannover, Germany
| | - Karl-Heinz Esser
- Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559, Hannover, Germany
| | - John Hellmann
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559, Hannover, Germany.,Present address: Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen (LANUV), Fisheries Ecology, Heinsberger Straße 53, D-57399, Kirchhundem-Albaum, Germany
| | - Dirk Willem Kleingeld
- Lower Saxony State Office for Consumer Protection and Food Safety, Veterinary Task-Force, Eintrachtweg 19, D-30173, Hannover, Germany
| | - Karl Rohn
- Institute for Biometry, Epidemiology, and Information Processing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Dieter Steinhagen
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559, Hannover, Germany.
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Jung-Schroers V, Adamek M, Boley A, Korshun A, Steinhagen D. Influence of a membrane-denitrification reactor on the microbial community of an aquaculture recirculation system. JOURNAL OF FISH DISEASES 2019; 42:141-146. [PMID: 30474176 DOI: 10.1111/jfd.12918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/28/2018] [Accepted: 09/28/2018] [Indexed: 06/09/2023]
Affiliation(s)
- Verena Jung-Schroers
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
| | - Mikolaj Adamek
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
| | - Angela Boley
- Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Stuttgart, Germany
| | - Anna Korshun
- Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Stuttgart, Germany
| | - Dieter Steinhagen
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
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