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Prosjektnummer

542042

Prosjektinformasjon

Prosjektnummer: 542042
Status: Avsluttet
Startdato: 01.01.2007
Sluttdato: 28.02.2010

Welfare of Farmed Fish from Harvest to Killing - Meeting the Future Challenge

Prosjektet har gitt en rekke resultater knyttet til bedøving og avliving av fisk, som har vært avgjørende for videre utvikling av slag- og elbedøving som metode. Det er også vist at laks er i stand til å tåle store, og tildels raske, temperaturfall uten vesentlig effekt på stress-parametere målt i blod og plasma. Resultatene er grundig beskrevet i egen sluttrapport.
 
Vitenskapelige artikler
Percussion and electrical stunning of Atlantic salmon (Salmo salar) after dewatering and subsequent effect on brain and heart activities (2010): http://www.sciencedirect.com/science/article/pii/S0044848609009910
 
Electrical stimulation of Atlantic salmon muscle and the effect on flesh quality (2010): http://www.sciencedirect.com/science/article/pii/S0044848610000426
 
Factors affecting residual blood and subsequent effect on bloodspotting in smoked Atlantic salmon fillets (2009):
 
Stunning, pre slaughter and filleting conditions of Atlantic salmon and subsequent effect on flesh quality on fresh and smoked fillets (2009): http://www.sciencedirect.com/science/article/pii/S0044848609000404 
 
Effect of pre-slaughter procedures on stress responses and some quality parameters in sea-farmed rainbow trout (Oncorhynchus mykiss) (2010): http://www.sciencedirect.com/science/article/pii/S0044848610005466 
 
Crowding, pumping and stunning of Atlantic salmon, the subsequent effect on pH and rigor mortis (2012): http://www.sciencedirect.com/science/article/pii/S0044848611008672 
 
Dr-grad delvis knyttet til prosjektet
Sedation and slaughter of Atlantic salmon (Salmo salar, L.) with carbon monoxide, and a possible regulatory role of neuroglobin (2012): https://bora.uib.no/handle/1956/6218 
Background
For salmon, cod and halibut, the fish are often live chilled prior to exsanguination with or without stunning. From 2007 a new slaughter directive act, put demands on that fish are stunned and killed unconsciously. Furthermore the welfare under CO2 supplement and chilling is questioned involving possible restrictions or ban. Although electrical and percussive stunning is thoroughly examined, little is known if permanent insensibility is reached in combination with exsanguination.
 
Considering that fish are ectotherms, adapted to low temperatures and often prechilled, death is likely a function of the temperature. Hypothermia and the subsequent effect on stress and metabolism have not been studied in fish and there exists a gap in knowledge in how hypercapnia affects the welfare and how it can be used to improve it. Good welfare practice is often associated with good quality. However, chilling and aerobe muscle activity can lead to an early onset of rigor but drip loss, colour, gaping and soft texture are associated to other factors such as rigor tension strength, pH, protolytic activity and temperature.
Objectives
To obtain knowledge on how stunning methods influence the welfare of farmed fish (salmon, cod and halibut) and seek solutions to promote the welfare, quality of the product and competitiveness for the farming industry.
 
Sub-objectives
1. Permanent insensibility: Can euthanasia be achieved through exsanguination or do we need to perform an additional kill?
2. Hypothermia: How does hypothermia interact with the welfare, directly by affecting the respiration or indirectly by reducing its metabolism?
3. Hypercapnia: How does hypercapnia affect the welfare, directly by release of stress responses or indirectly by sedating the fish?
4. Technology: Improve existing stunning methods.
5. Total Product Quality: Solutions will be sought to improve welfare issues that works hand in hand with reduced production costs and increased quality and shelf life.
6. Predictive welfare tools: Develop practical welfare guidelines for the fish farming industry and the National Food Authorities.
Expected project impact
Summarizing the results by models will provide welfare guidelines for industrial, legislative and scientific communities. The project will also provide solutions to promote the welfare, quality of the product and competitiveness for the farming industry.
Project design and implementation
Use of EEG, ECG will answer task 1. Use of tunnel resiprometers on cannulated fish and online blood analyses will reveal how the fish physiologically respond to hypothermal conditions during normoxic, hypoxic and hypercapnic conditions. Metabolism and respiratory drive as a function of temperature will also be calculated.
 
The project will seek new technology using magnetic fields for measuring muscular and neural activity in fish. The project will also identify the connections between product quality and welfare, separating events as rigor mortis, drip loss, shelf life, colour and soft texture, so-called Total Product Quality.
 
The project will provide funding towards 4 MSc & 1 PhD candidate.
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