On-farm evaluation of the Salmon Welfare Index Model (SWIM 1.0): theoretical and practical considerations

Folkedal, Ole; Pettersen, J.M.; Bracke, M.B.M.; Stien, Lars Helge; Nilsson, Jonatan; Martins, Catarina I.M.; Breck, Olav; Midtlyng, Paul J.; Kristiansen, Tore

doi:10.7120/09627286.25.1.135

Cited by 29 publications

(14 citation statements)

References 29 publications

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“…; Folkedal et al . ) prior to and after treatment to enable assessment of the sub‐lethal effects of treatment on fish welfare; (7) Daily mortality rates instead of monthly, which will allow better identification of mortality caused by delousing treatments and other operations on the farm. Daily mortality rates are already registered by companies and could be easily integrated from their farm management software.…”

Section: Resultsmentioning

confidence: 99%

Salmon lice treatments and salmon mortality in Norwegian aquaculture: a review

Overton

Dempster

Oppedal

et al. 2018

Reviews in Aquaculture

215

162

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With the expansion of Atlantic salmon aquaculture, the economic and ecological impacts of salmon lice (Lepeophtheirus salmonis) has increased. Norway battles this problematic parasite with various control and preventative methods within farms. We analysed two national-level databases to examine the number of operations reported each year from 2012 to 2017 and salmon mortality rates attributable to each operation type. From 2012 to 2017, 1.4 times more operations were registered, despite only limited increases in biomass produced across this period. We detected a rapid and recent paradigm shift in the industry's approach to lice control from chemotherapeutant to non-medicinal operations. Chemotherapeutants (azamethiphos, cypermethrin, deltamethrin and hydrogen peroxide) dominated operations from 2012 to 2015 (>81%), while mechanical and thermal treatments dominated in 2016 and 2017 (>40% and >74%, respectively). Thermal operations caused greatest mortality increases (elevated mortality for 31% of treatments), followed by mechanical (25%), hydrogen peroxide (21%), and azamethiphos, cypermethrin and deltamethrin (<14%). Temperature, fish size and pre-existing mortality rates all influenced post-treatment mortality outcomes. For chemotherapeutants, mortality increased as sea temperature increased. For mechanical and thermal treatments, mortalities increased at low (4-7°C) and high (13-16°C) temperatures. Fish with high pre-existing mortality (0.25-1.0% mortality the month before treatment) experienced increased mortality after treatment, and large fish (≥2 kg) were more susceptible to increased mortality than small (<2 kg). Generally, thermal, mechanical and hydrogen peroxide operations performed better in 2017 compared to 2015 and 2016, as the percentage of mortality observations were lower. With mechanical and thermal treatments now predominant, future research and industry development should prioritise reducing mortality and improving post-treatment outcomes.

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Section: Resultsmentioning

confidence: 99%

Salmon lice treatments and salmon mortality in Norwegian aquaculture: a review

Overton

Dempster

Oppedal

et al. 2018

Reviews in Aquaculture

215

162

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“…In addition, there is a rising public concern for the welfare of captive fish and their difficulty to develop natural behaviors (43). Fish welfare has been defined as the quality of life experienced by the animal itself, such experience is seen as the animal's qualitative assessment of fulfillment of their welfare needs (3, 44). Frequently, fins damage and higher growth rates (Fulton index) are increasingly being used as potential indicators of the welfare of fish (16, 45).…”

Section: Discussionmentioning

confidence: 99%

Thermal Modulation of Monoamine Levels Influence Fish Stress and Welfare

et al. 2018

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Fish are ectotherm organisms that move through different thermal zones according to their physiological requirements and environmental availability, a behavior known as thermoregulation. Thermoregulation in ectothermic animals is influenced by their ability to effectively respond to thermal variations. While it is known that ectotherms are affected by thermal changes, it remains unknown how physiological and/or metabolic traits are impacted by modifications in the thermal environment. In captivity (land-based infrastructures or nets located in the open sea), fish are often restricted to spatially constant temperature conditions within the containment unit and cannot choose among different thermal conditions for thermoregulation. In order to understand how spatial variation of temperature may affect fish welfare and stress, we designed an experiment using either restricted or wide thermal ranges, looking for changes at hormonal and molecular levels. Also, thermal variability impact on fish behavior was measured. Our results showed that in Atlantic salmon (Salmo salar), a wide thermal range (ΔT 6.8°C) was associated with significant increases in monoamines hormone levels and in the expression of clock genes. Aggressive and territoriality behavior decreased, positively affecting parameters linked to welfare, such as growth and fin damage. In contrast, a restricted thermal range (ΔT 1.4°C) showed the opposite pattern in all the analyzed parameters, therefore, having detrimental effects on welfare. In conclusion, our results highlight the key role of thermal range amplitude on fish behavior and on interactions with major metabolism-regulating processes, such as hormone performance and molecular regulatory mechanisms that have positive effects on the welfare.

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“…In the past, a semantic modelling methodology has been developed to assess overall welfare, expressed as a score on a scale from 0 to 10, and used to prioritize welfare aspects in a systematic, formalised and science-based way [3, 4]. This methodology, which involved empirical as well as expert validation surveys, has been applied to various farmed species, including pigs (Sow WELfare Model (SOWEL), [5], PIGTAIL on tail biting [6, 7] and RICHPIG on pig enrichment [8]), laying hens [9], dairy cattle [10], calves [11]) and farmed salmon [12–14]. The FOWEL (Fowl WELfare) model for laying hens was previously used in decision making in the field of effective altruism, but its validity has been questioned [15, 16].…”

Section: Introductionmentioning

confidence: 99%

Broiler welfare trade-off: A semi-quantitative welfare assessment for optimised welfare improvement based on an expert survey

et al. 2019

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In order to support decision making on how to most effectively improve broiler welfare an innovative expert survey was conducted based on principles derived from semantic modelling. Twenty-seven experts, mainly broiler welfare scientists (n = 20; and 7 veterinarians), responded (response rate 38%) by giving welfare scores (GWS, scale 0–10) to 14 benchmarking housing systems (HSs), and explaining these overall scores by selecting, weighing and scoring main welfare parameters, including both input and output measures. Data exploration followed by REML (Linear Mixed Model) and ALM (Automatic Linear Modelling) analyses revealed 6 clusters of HSs, sorted from high to low welfare, i.e. mean GWS (with superscripts indicating significant differences): 1. (semi-natural backyard) Flock (8.8a); 2. Nature (7.7ab), Label Rouge II (7.4ab), Free range EU (7.2ab), Better Life (7.2ab); 3. Organic EU (7.0bc), Freedom Food (6.2bc); 4. Organic US (5.8bcd), Concepts NL (5.6abcdef), GAP 2 (4.9bcd); 5. Conventional EU (3.7de), Conventional US (2.9ef), Modern cage (2.9abcdef); 6. Battery cage (1.3f). Mean weighting factors (WF, scale 0–10) of frequently (n> = 15) scored parameters were: Lameness (8.8), Health status (8.6), Litter (8.3), Density (8.2), Air quality (8.1), Breed (8.0), Enrichment (7.0) and Outdoor (6.6). These did not differ significantly, and did not have much added value in explaining GWS. Effects of Role (Scientist/Vet), Gender (M/F) and Region (EU/non-EU) did not significantly affect GWS or WF, except that women provided higher WF than men (7.2 vs 6.4, p<0.001). The contribution of welfare components to overall welfare has been quantified in two ways: a) using the beta-coefficients of statistical regression (ALM) analyses, and b) using a semantic-modelling type (weighted average) calculation of overall scores (CalcWS) from parameter level scores (PLS) and WF. GWS and CalcWS were highly correlated (R = ~0.85). CalcWS identified Lameness, Health status, Density, Breed, Air quality and Litter as main parameters contributing to welfare. ALM showed that the main parameters which significantly explained the variance in GWS based on all PLS, were the output parameter Health status (with a beta-coefficient of 0.38), and the input parameters (stocking) Density (0.42), Litter (0.14) and Enrichment (0.27). The beta-coefficients indicated how much GWS would improve from 1 unit improvement in PLS for each parameter, thus the potential impact on GWS ranged from 1.4 welfare points for Litter to 4.2 points for Density. When all parameters were included, 81% of the variance in GWS was explained (77% for inputs alone; 39% for outputs alone). From this, it appears that experts use both input and output parameters to explain overall welfare, and that both are important. The major conventional systems and modern cages for broilers received low welfare scores (2.9–3.7), well below scores that may be considered acceptable (5.5). Also, several alternatives like GAP 2 (4.9), Concepts NL (5.6), Organic US (5.8) and Freedom Food (6.2) are unaccep...

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On-farm evaluation of the Salmon Welfare Index Model (SWIM 1.0): theoretical and practical considerations

Cited by 29 publications

References 29 publications

Salmon lice treatments and salmon mortality in Norwegian aquaculture: a review

Salmon lice treatments and salmon mortality in Norwegian aquaculture: a review

Thermal Modulation of Monoamine Levels Influence Fish Stress and Welfare

Broiler welfare trade-off: A semi-quantitative welfare assessment for optimised welfare improvement based on an expert survey

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