April 2023

Empirical Research in Farmed Animal Advocacy 

April 2023

This list includes all studies we know of published in April that:

Previous versions: Previous lists
Please send any suggestions for this list to alina.salmen@animalcharityevaluators.org.

Animal-free foods

A sensory study on consumer valuation for plant-based meat alternatives: What is liked and disliked the most?


The food sector has witnessed a surge in the production of plant-based meat alternatives that aim to mimic various attributes of traditional animal products; however, overall sensory appreciation remains low. This study employed open-ended questions, preference ranking, and an identification question to analyze sensory drivers and barriers to liking four burger patties, i.e., two plant-based (one referred to as pea protein burger and one referred to as animal-like protein burger), one hybrid meat-mushroom (75% meat and 25% mushrooms), and one 100% beef burger. Untrained participants (n=175) were randomly assigned to blind or informed conditions in a between-subject study. The main objective was to evaluate the impact of providing information about the animal/plant-based protein source/type, and to obtain product descriptors and liking/disliking levels from consumers. Results from the ranking tests for blind and informed treatments showed that the animal-like protein was the most preferred product, followed by the 100% beef burger. Moreover, in the blind condition, there was no significant difference in preferences between the beef burger and the hybrid and pea protein burgers. In the blind tasting, people preferred the pea protein burger over the hybrid one, contrary to the results of the informed tasting, which implies the existence of affecting factors other than pure hedonistic enjoyment. In the identification question, although consumers correctly identified the beef burger under the blind condition, they still preferred the animal-like burger.

Sogari, G., Caputo, V., Joshua Petterson, A., Mora, C., & Boukid, F. (2023). A sensory study on consumer valuation for plant-based meat alternatives: What is liked and disliked the most? Food Research International, 112813. https://doi.org/10.1016/j.foodres.2023.112813 

Can in vitro meat be a viable alternative for Turkish consumers?


High meat consumption places a heavy burden on the environment. This study aimed to highlight the practices of Turkish consumers in consuming red meat and to understand their attitudes toward in vitro meat (IVM). The relationships between red meat consumption rationalization, attitudes toward IVM, and intentions to consume IVM were examined for Turkish consumers. It was found that Turkish consumers' attitudes toward IVM were averse. Even if the respondents considered IVM a viable alternative to conventional meat, they did not consider it ethical, natural, healthy, tasty, or safe. Additionally, Turkish consumers did not evince interest in regular consumption or intention to try IVM. Although various studies have focused on consumers' attitudes toward IVM in developed economies, the current study is the first attempt to understand the phenomenon in the Turkish market as an emerging economy. These results provide important information for researchers and stakeholders in the meat sector, such as manufacturers and processors.

Baybars, M., Ventura, K., & Weinrich, R. (2023). Can in vitro meat be a viable alternative for Turkish consumers? Meat Science, 201, 109191. https://doi.org/10.1016/j.meatsci.2023.109191 

Consumer acceptance of novel sustainable food technologies: A multi-country survey


Efforts to reduce the environmental burden of agri-food systems have fostered technological advances to enable a transition towards more sustainable production and diets. Such a transition is only possible if consumers are willing to accept foods produced using novel technologies. Previous research on consumer acceptance has generally focused on individual technologies in isolation, rendering comparisons across studies difficult, and mostly considered average acceptance without devoting attention to individual differences among consumers. Additionally, available data overwhelmingly pertained to European and North American consumers, whereas much less is known about consumer perception in non-Western countries. Against this backdrop, this study examined consumer acceptance and perception of a wide range of novel, sustainable food technologies in four countries (Australia, India, Singapore, and the USA, N = 2494 in total) using survey methodology. For each technology, willingness-to-consume (WTC, operationalized as expected frequency of consumption), emotional associations, and situational appropriateness responses were collected. All measures revealed major differences in consumer perception of novel food technologies, identifying three groups: 1) technologies with high consumer acceptance comprising vegetables from urban farming and vegetables packaged in a modified atmosphere; 2) technologies with medium consumer acceptance comprising fish reared in aquaponics systems, plant-based alternatives to meat and dairy, and gene-editing; 3) technologies with low consumer acceptance comprising insect ingredients, cell-cultured meat and cell-cultured fish. Technologies in the high acceptance group were perceived as healthier and apt to move one's diet in a more sustainable direction, whereas consumers had issues associating specific benefits to the less accepted technologies. Cross-cultural differences were identified. Most notably, Indian consumers responded more positively to all novel food technologies, especially compared to consumers in the US and Australia. Finally, four pan-national consumer segments were identified based on their overall patterns of acceptance towards novel food technologies. The segments varied primarily in terms of baseline WTC (low, medium, and high), indicating that consumers tended to accept or reject novel food technologies regardless of their nature. The segment characterized by a high acceptance included only about a fifth of the consumers, showing that WTC towards novel food technologies for most consumers ranged from moderate to outright rejection. Collectively, the findings of this study suggest that consumers' general skepticism regarding technologies in the food domain remains a significant challenge towards achieving more sustainable diets.

Giacalone, D., & Jaeger, S. R. (2023). Consumer acceptance of novel sustainable food technologies: A multi-country survey. Journal of Cleaner Production, 408, 137119. https://doi.org/10.1016/j.jclepro.2023.137119 

Design-led innovation for more plant-based food: An interdisciplinary approach to more consumer-centric product development


A more plant-based diet will contribute to food sustainability. Achieving this change requires collaboration across disciplines which is not easy to achieve. This article illustrates how interdisciplinary collaboration in a large research project can be facilitated through a design-led innovation process juxtaposing approaches from design and science. Consumer insights were used in creative workshops to ideate and develop packaging and product concepts for plant-based food focusing on ‘environment’, ‘health’ and ‘Norwegian’ design imperatives. Learning loops of alignment – creation – feedback were applied to design and test six packaging prototypes of two product categories (Pea Porridge, Faba Bean Drink). Qualitative feedback was collected from 147 consumers and a quantitative survey with 1102 Norwegian consumers tested product expected liking and product-concept match. Younger consumers and users of plant-based products exhibited a higher expected liking vs. non-users and older respondents. Packaging design adopted for specific consumer segments can positively contribute to a shift to more plant-based diets. We show how a dynamic interdisciplinary innovation approach can be powerful to creating new product ideas, getting consumers’ input and fostering collaboration and learning among disciplines. We offer other researchers and the food industry actionable opportunity areas and design imperatives for their innovation activities around plant-based food.

Gonera, A., Milford, A. B., Prexl, K.-M., Romm, J., Berget, I., & Varela, P. (2023). Design-led innovation for more plant-based food: An interdisciplinary approach to more consumer-centric product development. International Journal of Food Design. https://doi.org/10.1386/ijfd_00057_1 

Plant-based fish analogs: A review


Recently, plant-based food has become important in the global food market. The increasing demand for plant-based food is a consequence of the increase in both environmental awareness and care for animal welfare as well as the changes in nutritional recommendations. Therefore, food producers are concentrating on fulfilling consumer needs by creating alternatives to animal-based products with comparable nutritional and sensory qualities but from plant-based sources. One promising trend is the production of plant-based fish. Thus, this work aimed to summarize the possibilities of creating plant-based fish analogs, including a review of alternatives to fish products currently available on the market and the possible use of the various ingredients to produce plant-based fish analogs like fillets, slices, as well as sticks, or burgers. Furthermore, the plant-based ingredients were characterized for potential use in fish analogs production. Additionally, the study includes technologies used for plant-based fish analogs production, e.g., texturization, 3D and 4D printing, electrospinning, etc. Furthermore, future perspectives were given considering the challenges and limitations in this range.

Nowacka, M., Trusinska, M., Chraniuk, P., Piatkowska, J., Pakulska, A., Wisniewska, K., Wierzbicka, A., Rybak, K., & Pobiega, K. (2023). Plant-based fish analogs: A review. Applied Sciences, 13(7), 4509. https://doi.org/10.3390/app13074509 

Cultured meat in cellular agriculture: Advantages, applications and challenges


The concept behind cellular agriculture is to produce new meat and plant product with almost little or zero meat or plant input by using their tissue or cell. It is a new approach that allows meat to be produced in a bioreactor rather than from farm animals. This concept also can be used by biotechnologists to make meat or skeletal tissue outside of an organism. The purpose of this paper is to review the types of production of cultured meat, potential benefits, and potential challenges in producing cultured meat. Two types of cultured meat production are highlighted in this review, as well as the reduction of environmental burden in food production, nutritional value, and animal welfare, as well as technical and ethical limitations in cultured meat production, public perception, and consumer acceptance of cultured meat. As a result, the concerns regarding the food supply in the face of expanding population and climate change have prompted more research on the importance of cultured meat. Cultured meat can be produced in several ways, and each has the potential to contribute to agricultural technology in ensuring food security, nutritional and hygienic requirements, and reduction of carbon. Cultured meat is a vital source of nutrition, particularly in developing nations where hunger is an issue. This review paper will assist researchers in identifying relevant information about cultured meat and the various perspective including religious perception in consuming and accepting this cultured meat.

Jahir, N. R., Ramakrishna, S., Abdullah, A. A. A., & Vigneswari, S. (2023). Cultured meat in cellular agriculture: Advantages, applications and challenges. Food Bioscience, 102614. https://doi.org/10.1016/j.fbio.2023.102614 

Animal welfare

A systematic review on whether regenerative agriculture improves animal welfare: A qualitative analysis with a One Welfare perspective


The welfare of animals in food-production systems is a cause of concern to the public. Regenerative agriculture was first used by the Rodale Institute and proposes to regenerate degraded components of ecosystems, aiming to be more than just sustainable. However, despite animal welfare being pushed to be part of the SDG agenda for 2030, there is no clarity on how regenerative agriculture impacts animal welfare. It is challenging to determine regenerative agriculture impacts on animal welfare, since it is not entirely defined. One Welfare could help define entry points for future research by studying animal welfare in connection with human welfare and environmental conservation. We aimed to analyse the extent to which positive animal welfare outcomes characterise regenerative agriculture systems in peer-reviewed articles and whether the narratives of such articles support that regenerative agriculture promotes animal welfare directly or indirectly by improving human welfare and environmental conservation. We searched papers including ‘regenerative agriculture’ using PRISMA-P, selecting animal welfare, human welfare, environment conservation terms, developed themes, and carried out analysis using Atlas.Ti8 and Causal Loop Diagram. We found that papers mainly linked animal welfare to animal health, human welfare to financial farm status and farmer’s self-awareness, and environmental conservation to soil improvement. Causal Loop Diagram indicated that regenerative agriculture had the potential to improve the health and nutrition components of animal welfare by enhancing financial farmers’ status/self-awareness (human welfare), and the soil (environmental conservation), reflecting that the processes that affect human welfare and environmental conservation could also affect animal welfare. However, information in papers remains insufficient to determine how regenerative agriculture impacts on animal welfare and research into regenerative agriculture needs to extend its focus on animal welfare and elucidate the regenerative agriculture principles leading to animal welfare.

Hargreaves-Méndez, M. J., & Hötzel, M. J. (2023). A systematic review on whether regenerative agriculture improves animal welfare: A qualitative analysis with a One Welfare perspective. Animal Welfare, 32. https://doi.org/10.1017/awf.2023.28

Economic evaluation of the transition to cage-free housing on the EU egg and pigmeat industries


This report aims to provide an objective economic analysis of the transition to cage-free housing in the European Union's egg and pigmeat industries. This report is based on the strongest and most relevant available scientific studies, as identified by a global systematic literature review. From several thousand publications, including both peer-reviewed studies and grey literature, we identified 13 high-quality sources for estimating the costs of egg production; 10 for the costs of pigmeat production; and 4 for consumer prices.

Overall, our conclusions demonstrate that the transition towards cage-free housing is likely to have a relatively small impact on producers and consumers, particularly if appropriate support is offered by official bodies in the EU and its Member States. Additionally, the experiences of other jurisdictions around the world provide evidence that an implementation timeline of around 3-5 years is reasonable. Read more in the full report below.

Springlea, R. (2023). Economic evaluation of the transition to cage-free housing on the EU egg and pigmeat industries. Animal Ask. https://www.animalask.org/post/economic-evaluation-of-the-transition-to-cage-free-housing-on-the-eu-egg-and-pigmeat-industries 

Review: The challenge to integrate animal welfare indicators into the Life Cycle Assessment


The transition to a more sustainable livestock sector represents one of the major challenges of our time. Life Cycle Assessment (LCA) is recognised as the gold standard methodology for assessing the environmental impact of farming systems. Simultaneously, animal welfare is a key component of livestock production and is intrinsically related to human and environmental well-being. To perform an overall on-farm sustainability assessment, it would be desirable to consider both the environmental impact and the welfare of the animals. The present work aimed to summarise and describe the methodologies adopted in peer-reviewed papers published to date, that combine animal welfare evaluation with LCA. Citations, retrieved from four bibliographical databases, were systematically evaluated in a multi-stage approach following the JBI and PRISMA scoping review guidelines. The searches identified 1 460 studies, of which only 24 were compliant with the inclusion criteria. The results highlighted how the environmental LCA was undertaken with a much more homogenous and standardised method than animal welfare assessment. When studies were grouped based on the type of animal welfare assessment performed: 16.7% used single welfare indicators, 45.8% multiple indicators, 8.3% applied existing validated protocols (i.e., TGI-200 and TGI-35L), 16.7% used non-validated protocols and 12.5% employed other methods. The papers were further classified with respect to the “5 Animal Welfare Domains Model”: the most assessed domain was “environment” (90.5% of the papers%), followed by “health” (52.4%), “nutrition” (33.3%), “behavioural interactions” (28.6%) and “mental state” (9.5%). None of the studies assessed all the domains simultaneously. In addition, 66.7% of papers (n = 16) aggregated the animal welfare indicators into a final score. Within these, only four papers proposed to associate the animal welfare scores with the LCA functional unit. An overall sustainability score, calculated with several different approaches to summarise the information, was provided by 46% of the papers. In summary, despite the topic’s relevance, to date, there is neither a consensus on the animal welfare assessment approach to be carried out (indicators selection and their aggregation) nor on the standardisation of an integrated animal welfare-LCA evaluation. The present review provides a basis for the development of common future guidelines to carry out a comprehensive, true-to-life and robust farm sustainability assessment.

Lanzoni, L., Whatford, L., Atzori, A. S., Chincarini, M., Giammarco, M., Fusaro, I., & Vignola, G. (2023). Review: The challenge to integrate animal welfare indicators into the Life Cycle Assessment. Animal : An International Journal of Animal Bioscience, 17(5), 100794. https://doi.org/10.1016/j.animal.2023.100794 

Where is the value? The impacts of sow gestation crate laws on pork supply and consumer value perceptions


Despite varying farm animal welfare laws being enacted and considered, it is unclear and unknown whether they generate sufficient benefits to justify their costs. This study asks how sow gestation crate laws that dictate minimum crate size, a particular farm animal welfare law, impact meat production and the subsequent value that consumers place on meat produced under the laws. An observational analysis leverages the 8 states that have implemented laws regarding gestating sow crates in a difference-in-differences framework using staggered adoption robust estimators. We then perform a consumer preference experiment using a contingent valuation design with treatment effects to separate out the heterogeneous beliefs about animal welfare law effects. The results of the study show that such laws initially reduce gross income and supply, but only gross income recovers. For consumers, they value the corresponding pork products more in accordance with their animal welfare beliefs but not quality. Such information on costs and benefits should be considered in future laws relating to gestation crate bans.

Blemings, B., Zhang, P., & Neill, C. L. (2023). Where is the value? The impacts of sow gestation crate laws on pork supply and consumer value perceptions. Food Policy, 117, 102447. https://doi.org/10.1016/j.foodpol.2023.102447   

Diet and diet change

Effects of experimentally induced self-affirmation on the openness to meat reduction and alternative protein sources


Introduction: Consumption of animals entails disregarding the pain of sentient beings, and acknowledging this can threaten an individual’s image of oneself as a moral person. Also, abstaining from meat in a meat-eating culture can threaten an individual’s valued group identity. Previous research on inter-group relations suggests that self-affirmation, affirmation of personally or collectively important values, can help individuals alleviate self-threats since it enhances one’s global self-image and decreases threat perceptions.

Methods: We tested for potential effects of self-affirmation on openness toward reducing meat consumption in an experimental study. Participants (N = 277) were randomized into an individual affirmation, group affirmation, or a control condition. Individual affirmation participants ranked a list of values and then wrote a short paragraph about their first-ranked value. Group affirmation participants did a similar task, focusing on the values of their ethnic group, while participants in the control condition had an unrelated task of ranking their color preferences. Participants then read a persuasive message presenting health risks related to meat consumption and the health benefits of reducing meat. Finally, they indicated their openness toward reducing meat consumption and acceptability of plant-based alternatives and lab-grown meat.

Results and Discussion: Results show that affirmed participants expressed more readiness to reconsider their meat consumption habits, reduced perceptions of vegetarianism as a threat to the local culture, and more positive perceptions of the idea of lab-grown meat. However, self-esteem and frequency of meat consumption pose important limitations to the experimental effects. We discuss the findings from the perspective of self-and collective identity threats and the potential of self-affirmations to create a more open debate about animal product consumption.

Branković, M., Budžak, A., Tulić, N., & Janković, J. (2023). Effects of experimentally induced self-affirmation on the openness to meat reduction and alternative protein sources. Frontiers in Psychology, 14. https://doi.org/10.3389/fpsyg.2023.1021891  

Meat or mitigation? That’s the question: Storylines in the Norwegian agricultural policy discourse on meat reduction


Ruminant meat (beef and lamb) is recognised as the food with the largest environmental impact in terms of greenhouse gas emissions. Yet reducing meat consumption and production is controversial. Resistance to change has been linked to policy lock-ins and asymmetries in power favouring the agri-food industry. At the same time, agricultural policy has been described as moving towards a post-exceptional, less compartmentalized field where food production is balanced against issues like climate and animal welfare. In this article, we explore how the discourse on meat reduction and greenhouse gas emissions are related to various other agricultural policy issues, using Norway as a case. Investigating the stakeholder submissions to the Norwegian government's ambitious proposal to reduce meat consumption and production in Climate Cure 2030, we identify three storylines in the discursive landscape. The first storyline is ‘It is time to increase production – not reduce it’ which we see as an exceptionalist storyline where arguments for the unique position of the sector contributing to national goals of food security and value creation should prevail. Another dominant storyline is ‘In our country, animal farming is sustainable’, which has typical post-exceptionalist features where nonproducer concerns, such as biodiversity and cultural landscapes, are seen as a net positive result of the grazing animals in Norway. The third storyline ‘The voices of consumers, animals and nature need to be included in policy networks’ also has strong post-exceptionalist viewpoints, but it calls for a radical restructuring of the sector, therefore, we see this as a radical post-exceptionalism. Our findings find little support for radical change, and for now, meat beats mitigation.

Larsson, J., & Vik, J. (2023). Meat or mitigation? That’s the question: Storylines in the Norwegian agricultural policy discourse on meat reduction. Journal of Rural Studies, 100, 103016. https://doi.org/10.1016/j.jrurstud.2023.103016   

Modelled impacts of farm-level adaptations in response to changed dietary patterns


Dietary change can facilitate a shift towards more sustainable agricultural practices and requires farmers to implement different farm adaptations. Here, we examine structural impacts on farms of several dietary scenarios towards changes in food demand pertaining to more regional food, more organic food and less meat in the metropolitan region of Vienna, Austria. We use a linear programming farm model underpinned by data on the intended adaptive behaviour of farmers based on a survey in the study region. The results show that for conventional farms, the intended adaptations from conventional to organic farming have higher effects on the investigated indicators (nitrogen import, gross margin, labour requirements) than adaptations concerning crop and livestock production patterns. A key finding is that, in terms of policy design, the positive effects on the investigated indicators can be achieved more easily by inciting switches towards organic farming than by inciting switches concerning crop and livestock production patterns. This would require dedicated policy measures at multiple levels, with payments specifically aimed at organic agriculture and other innovative, agro-ecological management practices. This article contributes to the modelling of regional-level food supply by showing that integrating empirical data into the farm model allows for a more targeted development of policy measures.

Wittmann, F., Eder, M., Schreck, K., & Grassauer, F. (2023). Modelled impacts of farm-level adaptations in response to changed dietary patterns. Applied Economics, 1–15. https://doi.org/10.1080/00036846.2023.2205099  

Personal, behavioral, and socio-environmental correlates of emerging adults’ sustainable food consumption in a cross-sectional analysis



Describe how dietary intake patterns of US young adults align with the EAT-Lancet Planetary Health Diet (PHD) sustainable diet goals and identify personal, behavioural, and socio-environmental correlates of sustainable intake.


Data on past-year dietary intake were captured using a FFQ. The PHD was applied to specific food groups, and a total PHD score was calculated. Linear regression models were used to identify associations between personal, behavioural and socio-environmental factors and PHD scores.


This cross-sectional analysis uses data from the second wave of EAT 2010–2018 (Eating and Activity over Time), a population-based longitudinal study recruited in Minnesota.


Ethnically/racially diverse group of participants (n 1308) with a mean age of 22·1 (SD 2·0) years.


The mean PHD score was 4·1 (SD 1·4) on a scale of 0–14, with 14 representing the most sustainable. On average, participants consumed fewer whole grains, fish, legumes, soya, and nuts than ideal for a sustainable diet, and an excess of eggs, added sugar, and meat. The PHD score was higher for participants with higher socio-economic status (SES) and greater educational attainment. Higher home availability of healthy food (β = 0·24, P < 0·001) and less frequent fast-food consumption (β = –0·26, P < 0·001) were the strongest correlates of PHD scores.


Results suggest that a high percentage of participants may not be achieving the sustainable diet goals defined by the PHD. Reductions in meat consumption and increases in plant-based foods are necessary to increase the sustainability of US young adults’ diets.

Wittmann, F., Eder, M., Schreck, K., & Grassauer, F. (2023). Modelled impacts of farm-level adaptations in response to changed dietary patterns. Applied Economics, 1–15. https://doi.org/10.1080/00036846.2023.2205099  

Triggering cognitive dissonance with textual information and images: Data from three experiments with meat-eaters


This article presents data from three experiments in which we triggered and measured cognitive dissonance in meat-eaters. Cognitive dissonance is a well-established concept in the social psychology literature; however, empirical measures are scarce. In all datasets, we used textual information and/or images related to meat consumption as means to trigger cognitive dissonance. Cognitive dissonance data was collected in Study 1 with a Likert scale, whereas Study 2 and 3 used a Semantic Bipolar scale. Each experiment was programmed with Qualtrics and consisted of four conditions. Data was collected online; Study 1 utilized social media to recruit participants while Study 2 and 3 were hosted on Prolific. All datasets contain items on participants’ socio-demographic background, liking of different food products, cognitive dissonance, and a measure of meat avoidance. The data can be used to analyze the effect of information provision on cognitive dissonance and meat avoidance. Moreover, the relationship between socio-demographic variables and cognitive dissonance, as well as other exploratory purposes regarding meat avoidance can be explored. Furthermore, researchers can use the data to investigate differences between Likert scales and Semantic Bipolar scales. This data is related to the paper Can images and textual information lead to meat avoidance? The mediating role of cognitive dissonance [1].

Weingarten, N., Lagerkvist, C.-J., Meraner, M., & Hartmann, M. (2023). Triggering cognitive dissonance with textual information and images: Data from three experiments with meat-eaters. Data in Brief, 48, 109116. https://doi.org/10.1016/j.dib.2023.109116 

Fish Welfare

A new window into fish welfare: A proteomic discovery study of stress biomarkers in the skin mucus of gilthead seabream (Sparus aurata)


Fish skin mucus is a dynamic external mucosal layer that acts as the first line of defense in the innate immune system. Skin mucus' exudation and composition change severely under stress, making it a valuable biofluid to search for minimally invasive stress markers. This study focused on the skin mucus proteome response to repetitive handling, overcrowding, and hypoxia, using Sparus aurata, an important species in the Mediterranean aquaculture, as a model. Biomarker discovery analysis was performed using label-free shotgun proteomics coupled with bioinformatics to unveil the most predictive proteins for the stressed phenotype. A mean of 2166 proteins were identified at a < 0.2% false discovery rate, from which the differentially abundant proteins (DAPs) were mainly involved in the immune system and protein metabolism. A sparse partial least squares regression analysis revealed a high correlation between DAPs and plasma physiological stress indicators. Feature selection, performed by recursive feature elimination followed by logistic regression analysis of the selected proteins, disclosed 28 candidate biomarkers with values of area under the curve >0.75. These minimally invasive biomarkers could be used in forthcoming species-specific stress management protocols to improve fish welfare and promote farmed fish safety, positive societal outcomes, and business sustainability.

Lindberg, S. K., Durland, E., Heia, K., Noble, C., Alvestad, R., & Difford, G. F. (2023). Digital scoring of welfare traits in Atlantic salmon (Salmo salar L.) - a proof of concept study quantifying dorsal fin haemorrhaging via hyperspectral imaging. Frontiers in Animal Science, 4. https://doi.org/10.3389/fanim.2023.1162384  

A systematic review and meta-analysis of basal and post-stress circulating cortisol concentration in an important marine aquaculture fish species, European sea bass, dicentrarchus labrax


Background: European sea bass is a species characterized by high and dispersed cortisol levels. The aim of the present study was to analyze all published data on basal and post-acute stress cortisol levels in this species. Methods: For this systematic review and meta-analysis the Web of Science and Scopus databases were searched for papers reporting plasma or serum cortisol levels in E. sea bass, without language or date restrictions. Data were extracted directly for the reported results and were analyzed separately for basal and post-acute stress levels, as well their standardized mean differences (SMD) using random-effects meta-analyses. Results: Of 407 unique records identified, 69 were eligible. Basal cortisol levels had a pooled effect of 88.7 ng mL−1 (n = 57), while post-acute stress levels were 385.9 ng mL−1 (n = 34). The average SMD between basal and post-stress was calculated to be 3.02 (n = 22). All analyses had a high between-study heterogeneity. Results for basal and post-stress levels were affected by the assay type and anesthesia prior to blood sampling. Conclusions: Cortisol levels in E. sea bass are higher than most studied fish species and display large heterogeneity. Application of stress led to elevated cortisol levels in all studies examined. In all cases, sources of between-studies heterogeneity were identified.

Samaras, A. (2023). A systematic review and meta-analysis of basal and post-stress circulating cortisol concentration in an important marine aquaculture fish species, European sea bass, dicentrarchus labrax. Animals : An Open Access Journal from MDPI, 13(8). https://doi.org/10.3390/ani13081340 

Digital scoring of welfare traits in Atlantic salmon (Salmo salar L.) - a proof of concept study quantifying dorsal fin haemorrhaging via hyperspectral imaging


Introduction: Morphological injuries are well-established Operational Welfare Indicators (OWIs) for farmed animals including fish. They are often scored manually by human observers and this process can be laborious and prone to subjectivity and error. In this study we evaluated the use of a hyperspectral imaging system to quantify the presence and severity of external haemorrhaging in Atlantic salmon focusing on dorsal fins as a proof of concept OWI.

Methods: Two inexperienced observers manually audited dorsal fin injuries on 234 post-smolt Atlantic salmon following a standardized protocol that scored fin erosion on a 0-3 scale and also classified the injury as active/healed. The same fish were then imaged with a hyperspectral camera system and the manually scored visual assessments were compared with hyperspectral images of the same fin. Hyperspectral images were processed to segment out the dorsal fin of each fish and the presence of blood in the tissue was quantified by analysing the spectral information, yielding a fin haemorrhaging index.

Results: The hyperspectral imaging platform was robust at detecting blood in fins and could help classify active injuries more accurately than human observers. The agreement between human scorers and the image analysis tool for classifying active bleeding vs healed/undamaged fins was good with a Cohen’s kappa of 0.81 and 0.90. Accuracy between the fin haemorrhaging index and the human observers was moderate (0.61 and 0.57) and on par with the agreement between the two human observers (0.68), demonstrating the difficulty in classifying injuries that result in a reduction in fin size but may or may not result in fin haemorrhaging.

Discussion: These results demonstrate the potential power of hyperspectral imaging to improve welfare audits in aquaculture, especially where manual injury classification schemes have potentially mixed traits that involve haemorrhaging. The data also suggests that the hyperspectral camera can detect bleeding that is not readily visible to the human eye. There is a need for further testing and validation to integrate these tools into existing welfare auditing programs, but the potential advantages of the automated approach include increased sensitivity, accuracy and throughput, while producing quantitative data for researchers or management.

Lindberg, S. K., Durland, E., Heia, K., Noble, C., Alvestad, R., & Difford, G. F. (2023). Digital scoring of welfare traits in Atlantic salmon (Salmo salar L.) - a proof of concept study quantifying dorsal fin haemorrhaging via hyperspectral imaging. Frontiers in Animal Science, 4. https://doi.org/10.3389/fanim.2023.1162384  

Fish meal replacement and early mild stress improve stress responsiveness and survival of fish after acute stress


Stress responsiveness and fish meal (FM) replacement are two of the most important concerns toward achieving sustainable aquaculture. The purpose of this study was to see how early mild stress (netting) and FM replacement with meat and bone meal (MBM) affected oscar (Astronotus ocellatus; 5.2 ± 0.9 g) growth, hematology, blood biochemistry, immune responses, antioxidant system, liver enzymes, and stress responses. Oscars were subjected to a 3 × 3 experimental design (three fish meal replacement levels: 250, 180 and 110 g/kg of FM in diets; three stress periods: 0-, 2- and 3-times early mild stress). After ten weeks of the experiment, FM levels in diets did not affect growth data, but the survival rate after the acute confinement (AC) stress was lower in 11FM treatments (47.7% compared to 67.7%) than others. Fish exposed to the 3Stress schedule had a lower growth (31.03 ± 6.50 g) and survival rate (55.5%) after the AC stress than the 2Stress group (38.92 ± 6.82 g and 70.0%). Lower survival and growth rate in the 3Stress and 11FM groups coincided with the lowest blood performance, total protein, lysozyme, complement C4, complement C3, immunoglobulin, superoxide dismutase, catalase, glutathione peroxidase, and the highest glucose, cortisol, low-density lipoprotein and aspartate aminotransferase serum levels. Altogether, this study revealed that it is possible to replace FM with MBM up to 28% (180 g/kg of FM) without negative effects on the growth and health of juvenile oscar as dietary 110 g/kg of FM impaired fish health. While fish welfare should be considered, we can conclude that mild stress (2Stress) during the farming period, but without adding excessive alternative protein sources, can improve the stress responsiveness of oscar.

Zare, M., Kazempour, M., Hosseini, H., Hosseini Choupani, S. M., Akhavan, S. R., Rombenso, A., & Esmaeili, N. (2023). Fish meal replacement and early mild stress improve stress responsiveness and survival of fish after acute stress. Animals : An Open Access Journal from MDPI, 13(8). https://doi.org/10.3390/ani13081314 

Prioritization of fish welfare issues in European salmonid aquaculture using the Delphi method


The European aquacultural sector is undergoing immense growth, and, generally, many more aquatic animals are farmed than land animals. However, the welfare of aquatic animals like fish has received less attention. This study focuses on the two largest contributors to Europe's aquaculture – Atlantic salmon and rainbow trout – farmed in cages in Northern Europe. An extensive literature review was conducted on potential welfare issues. These issues were grouped into five provisions / welfare aims according to an animal welfare framework adapted to fish. To set priorities among the issues, a Delphi assessment was performed, for which experts had to rate each issue based on the severity, duration, and prevalence. The participants were also asked to propose interventions to tackle the main issues. The three main welfare issues identified were ineffective prevention of diseases, sea lice treatment issues, and poor conditions during husbandry practices. Examples of interventions to improve the three main issues are lowering the stocking density, better monitoring, and specifically to prevent diseases, including sea lice, also developing more effective vaccines. This study provides valuable insights into which fish welfare issues should be tackled more urgently in European salmonid aquaculture. Future research could assess interventions more in depth and conduct similar studies for other aquatic farm animals and regions.

van den Boogaart, L., Slabbekoorn, H., & Scherer, L. (2023). Prioritization of fish welfare issues in European salmonid aquaculture using the Delphi method. Aquaculture, 572, 739557. https://doi.org/10.1016/j.aquaculture.2023.739557 

Human-animal relations

Animals are diverse: Distinct forms of animalized dehumanization


The animal stereotype approach dissolves ‘animals’ into diverse images depending on their species. First, we reviewed recent research showing the attributes socially ascribed to different animal species. Next, we discussed how the animal stereotype approach may complement dehumanization by broadening the distinct forms of animalized dehumanization based on 1) intentions (warm, friendly, and harmful), 2) abilities (perceptual and cognitive), 3) physical appearance (size, aesthetic appeal), 4) affective capacities, 5) physiological needs, and 6) domestic–wild nature.

Sevillano, V., & Fiske, S. T. (2023). Animals are diverse: Distinct forms of animalized dehumanization. Current Opinion in Behavioral Sciences, 51, 101265. https://doi.org/10.1016/j.cobeha.2023.101265 

Emotional response to pictures of farm animals: Influence of picture content and recipient characteristics


Pictures play a dominant role in communication about livestock farming. They are used by competing lobby groups not only to inform their audience cognitively but also to target emotionally. However, few studies have looked at the effects pictures from livestock farming have on recipients. In this study, we used an online survey to investigate the emotional response in the dimensions pleasure and arousal to pictures showing farm animals of the animal classes fish, birds, and mammals in different circumstances. The results show that pictures depicting farm animals in an outdoor environment led to high pleasure and low arousal. Looking at pictures showing animals kept indoors led to less pleasure and higher arousal, a response that was further intensified when recipients were confronted with pictures of suffering animals. While the recipients’ characteristics investigated in this study, i.e. professional background, belief in animal mind and personality traits, had no influence on emotional response to pictures showing farm animals outdoors, they affected emotional response to pictures depicting farm animals indoors and suffering. We discuss how awareness of the individuality of emotional response and reflection on one’s own emotional states related to livestock farming might lead to more animal and human welfare and a more respectful dialogue between opposing groups.

Schröter, I., & Mergenthaler, M. (2023). Emotional response to pictures of farm animals: Influence of picture content and recipient characteristics. International Journal on Food System Dynamics. https://doi.org/10.18461/ijfsd.v14i2.f4 

Veg*ns and advocates 

Conceptualizations of happiness and vegetarianism: Empirical evidence from University students in Spain


Vegetarianism improves human and planetary health in addition to animal welfare. Motivations for meat-reduced diets include health-related and ethical reasons, with the latter being the main driver for eschewing meat. However, evidence on vegetarian happiness is inconclusive and the results reported are mixed. This constitutes a challenge for policy aiming to encourage people to shift toward plant-based diets. In this research, we aim to provide some evidence on this question: to what extent is there a link between the different moral codes related to ideas of happiness and vegetarianism? To do so, we apply the happiness moral codes from the Conceptual Referent Theory, and assess vegetarianism from the perspective of the psychological aspect of vegetarian identity (flexitarian, pescatarian, lacto-ovo vegetarian, and vegan) and dietary behavior (vegetarian self-assessment scale). Analyzing a sample of university students in Spain, we discover that some happiness constructs (tranquility, fulfilment, and virtue) are positively related to vegetarianism while others are inversely related (enjoyment and stoicism). In terms of policy implications, we find that ethical grounds one holds on happiness in relation to vegetarianism may play a role in fostering or hindering plant-based lifestyles.

Krizanova, J., & Guardiola, J. (2023). Conceptualizations of happiness and vegetarianism: Empirical evidence from University students in Spain. Journal of Happiness Studies. https://doi.org/10.1007/s10902-023-00650-6 

Consumption of meat and dairy substitute products amongst vegans, vegetarians and pescatarians


Background: An increasing number of people adhere to plant-based diets, and the market for plant-based meat and dairy substitute products has been expanding rapidly.

Objective: To examine total intake of macronutrients and salt in a sample of Norwegian vegans, vegetarians and pescatarians; the consumption frequency of plant-based meat and dairy substitutes and raw ingredients used in these products; and the contribution to total macronutrient and salt intake from these products.

Design: A cross-sectional design using single 24-h dietary recall to assess the intake of macronutrients, salt and substitute products that the participants (n = 158 Norway residents [age 18–60 years]: vegans [n = 83]; vegetarians [n = 47]; pescatarians [n = 28]) consumed. The chi-square test with pairwise comparisons and the Kruskal-Wallis test with post hoc test were used to compare differences between diet groups. Macronutrient and salt intake were assessed relative to the Nordic Nutrition Recommendations (NNR).

Results: Dietary macronutrient intake fell within NNR recommendations, with a favourable distribution of fatty acids and high levels of dietary fibre. Most of the vegans (90%), vegetarians (68%) and pescatarians (64%) consumed meat or dairy substitutes. The main raw ingredient in the substitute products was soy, followed by oats and peas. Overall, substitute products contributed to 12% of total energy and 16% of total salt intake. The substitute products contributed to higher saturated fatty acid (SFA) intake amongst vegans (27% of total SFA intake) compared with vegetarians (10%) and pescatarians (8%). Moreover, substitute products contributed to higher protein intake in vegans (19%) compared with pescatarians (7%).

Conclusion: Most participants consumed meat or dairy substitute products, suggesting that these products are included regularly in Norwegian plant-based diets. Furthermore, substitute products may contribute to dietary fat, SFA and protein intake amongst vegans.

Tonheim, L. E., Groufh-Jacobsen, S., Stea, T. H., & Henjum, S. (2023). Consumption of meat and dairy substitute products amongst vegans, vegetarians and pescatarians. Food & Nutrition Research, 67. https://doi.org/10.29219/fnr.v67.9081 


Thanks to suggestions by the RECAP group, the Fish Advocacy Slack group, the research library of Faunalytics, the FAST list, and suggestions by ACE staff. 

Search terms:

Meat AND behavior

Meat AND behaviour

Meat AND consumer behavior

Meat AND consumer behaviour

Meat AND attitudes

Meat AND preferences

Meat AND consumption

Meat AND reduction

Cultured meat

Cultivated meat

Clean meat

In vitro meat

Plant based meat

Plant based diet



Animal advocacy 

Animal welfare

Aquatic animal welfare

Fish welfare 


“Human-animal relations”

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