Species‐specific welfare aspects of the main systems of stunning and killing of farmed Seabass and Seabream

Farmed fish welfare during slaughter in Italy: survey on stunning and killing methods and indicators of unconsciousness

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.

Impact of Diets Containing Plant Raw Materials as Fish Meal and Fish Oil Replacement on Rainbow Trout (Oncorhynchus mykiss), Gilthead Sea Bream (Sparus aurata), and Common Carp (Cyprinus carpio) Freshness

The present study aimed to evaluate whether the total or high substitution of fish meal (FM) and fish oil (FO) by sustainable plant raw materials (plant meal and oils) in long-term feeding for rainbow trout, gilthead sea bream, and common carp can result in spoilage alterations during ice storage. These three species were fed throughout their whole rearing cycle with plant-based diets and compared to counterparts that received FM/FO-based diets or commercial-like diets. Sensory QIM schemes adopted for these species and ATP breakdown products (K-value and components) were used to evaluate the freshness. Sensory acceptability of 14, 15, and 12 days was found for rainbow trout, gilthead sea bream, and common carp, respectively. This corresponded to K-values of approximately 80%, 35%, and 65% for rainbow trout, gilthead sea bream, and common carp, respectively. No major effect of dietary history on postmortem shelf life was shown for gilthead sea bream and common carp; neither sensory-perceived nor chemical freshness showed diet-related differences. Rainbow trout fed with the plant-based diet exhibited slightly worse sensory freshness than fish fed with FM/FO-based diets, at the end of shelf life. These findings imply that FM and FO can be successfully substituted without major impacts on shelf life of fish.

Modelling Farm Animal Welfare

The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively) based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.