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Sturgeon farming poses an interesting decision: give priority to highly prized caviar or meat. Indeed, sturgeons are mainly reared in aquaculture to produce caviar. However, the economic profitability of a sturgeon farm also depends on the existence of a meat market. Meat is still an important product for sturgeon farmers once the stock of caviar-producing females has been established. This paper takes a case study approach and analyses how an Italian producer addresses the trade-off, adopting a methodology that measures the value of the economic productivity of production inputs, e.g., the measure of the profitability of the inputs, and compares them with the costs of the inputs and the prices of the outputs. This analysis is the first attempt, to our knowledge, to adopt an economic analysis to address this choice problem, based on a very representative case study. This helps monitor whether the farm's production choices are economically efficient and effective and whether and how those can be improved. The results show that the farm maximizes profit but does not reach its optimal production level. This implies that both (1) producing more output and (2) a further switch to caviar production for less meat are economically efficient production strategies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Consumer interest in safeguarding animal welfare and increased demand for fresh aquatic products support the need to understand the effects of stunning methods used in aquaculture on the biochemical process affecting fish fillet quality. The present paper aimed at comparing electrical stunning (ES) and cold shock (ICE) in Salmo carpio, an Italian endemic under‐investigated species. Rigor mortis evolution, fillet adenosine 5′‐triphosphate (ATP), shape, colour, pH and water holding capacity were assessed by integrating chemical and image analyses. RESULTS: Seventy‐two fish (24 fish per treatment) were stunned by ES, ICE or anaesthesia (AN, used as control), then percussively slaughtered. ES and ICE hastened rigor mortis onset and resolution (21 and 28 h post mortem) compared to AN. This was confirmed by the faster ATP degradation in ES and ICE. Fillet shape features varied during rigor mortis, according to the stunning method, with the perimeter showing irreversible variation in ES and ICE groups. Initial circularity was recovered only in AN, while ICE and ES fillets showed significantly different values, between 0 and 192 h. CONCLUSION: ES is a promising stunning technique for S. carpio, but parameters should be optimized, because of the adverse effect on muscle activity which caused a fast pH drop, and the presence of blood spots in the fillets. Further studies are needed to understand whether fillet shape changes can interfere with filleting or fillet processing and consumer appreciation. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]