An optimal method for stunning animals before slaughter should result in instantaneous and irreversible insensibility. Today, there are various stunning and slaughter practices used around the world for farmed fish. With aquaculture being a growing food sector, the welfare of the animals used has become increasingly important in the consciousness of consumers, researchers and regulatory bodies. With growing research into the subject matter, an overview to summarize and examine how these practices impact on the welfare of the fish, and how well they conform to animal welfare legislation, is warranted to minimize the suffering of farmed fish. Stunning practices used in aquaculture include methods such as electrical and percussive stunning, carbon dioxide and asphyxiation. Each with its own level of effectiveness in terms of how fast the method results in loss of consciousness, whether or not the effect is reversible and how the welfare of the fish is affected as determined by behavioural and physiological stress responses. It was concluded that there is no unambiguous answer as to which stunning method is optimal in regard to animal welfare in modern day aquaculture. The optimal method for a given facility is influenced by factors like practicalities relating to each individual method as well as legislation on EU and national level. Suggestions were made for future research.

Bovine respiratory disease (BRD) costs the cattle industry millions of dollars in costs in treatment and loss every year in the United States. A significant pathogen often contributes to BRD is Bovine Herpesvirus 1 (BoHV-1), a double stranded DNA virus with the ability to establish latency in the trigeminal ganglia and neurons. Primary infection with BoHV-1 results in immunosuppression that increases the risk of secondary bacterial infection and pneumonia. Because herpesviruses infect their hosts for life and can be reactivated in times of stress, BoHV-1 can present a recurring risk of BRD. The following research aims to expand the knowledge of the genome of this costly agricultural pathogen and provide evidence of viral features that can be further explored to increase the efficiency of its control.

The research presented in this thesis focuses on an innovative use of digital imaging, and the machine learning techniques to assess the body rumen fill scoring in dairy cows. This study aims to enhance the efficiency of monitoring and managing dairy cow health, which is crucial for the dairy industry's productivity and sustainability. The primary objective was to develop an automated annotation system fore valuating rumen fill status in dairy cows using digital images extracted from recorded videos. This system leverages advanced machine learning algorithms and neural networks, aiming to mimic manual assessments by veterinarians and specialists on farms. To achieve the above objectives, this thesis made use of already existing video records from a Swedish dairy farm hosting mainly the Swedish Redand the Swedish Holstein breeds. A subset of these images were then processed, manually classified using a modified rumen fill scoring system based on visual assessment, and supervised classification algorithms were trained on 277 manually annotated images. The thesis explored various machine learning techniques for classifying these images, including Logistic Regression, Support Vector Machine (SVM), and a Deep Neural Network using the VGG16 architecture. These models were trained, validated, and tested with a dataset that included variations in cow color patterns, aiming to determine the most effective approach for automated rumen fill scoring.The results indicated that while each model had its strengths and weaknesses, the simple logistic model was performing the best in terms of test accuracy and F1 score. This research contributes to the field of precision livestock farming, particularly in the context of dairy farming. By automating the process of rumen fill scoring, the study aims to provide dairy farmers with a reliable, efficient, and cost-effective tool for monitoring cow health. This tool has the potential to enhance dairy cow welfare, improve milk production, and support the sustainability of dairy farming operations. However, at the current state, the model accuracy of the best model was only moderate. There is a need for further improvement of the prediction performance possibly by adding more cow images, using improved image processing, and feature engineering.

This study evaluates the spatial and temporal impacts of implemented Best Management Practices (BMP) on stream water quality under baseflow conditions in a stream segment affected by livestock production. The BMPs includes 10-m fenced riparian zone and crossing paths along the reach segment. Grab water samples and water quality monitoring were collected biweekly from July 2019 to March 2022. Water quality parameters included temperature, dissolved oxygen, electric conductance, total dissolved solids, turbidity, and pH. Water samples were lab analyzed for sediments and nutrients. Results evidenced poor water quality before BMPs implementation, with nutrient concentrations exceeding the nation's and state's criteria. Two years after implementation, BMPs favored seasonal and spatial reductions in nutrient, sediment concentrations, and improved water quality parameters. Present results and subsequent stream monitoring should create awareness in private owners to extend the implementation of a riparian zone and other BMPs that improves stream water quality and health.

Den domesticerade kaninen (Oryctolagus cuniculus) är idag ett vanligt sällskapsdjur världen över. Sällskapskaniner framhålls som det tredje mest populära sällskapsdjuret i Sverige, efter hund och katt. Trots detta behandlar endast en mycket liten andel av den övergripande forskningen inom ämnet hälsa- och välfärd just kanin. Den här studien har undersökt inverkan på sällskapskaninens välfärd av kaninägare med eller utan tidigare erfarenhet, sjukdomsbild, samt kaninägares preferenser - och om detta är faktorer som påverkar sällskapskaninens välfärd i Sverige. Studien genomfördes som en enkätundersökning, besvarad av 147 deltagare bosatta i Sverige. Enkäten publicerad i nätverkstjänsten Facebook och fanns tillgänglig under tidsperioden 23:e April - 7:e Maj, 2021. Mer än 50 % av deltagarna saknade erfarenhet och kunskap om kaniner innan de skaffade sin första kanin. Över 37 % höll sina kaniner ensamlevande, och mer än 21 % inhyste sina kaniner i bur. Behovet av veterinärvård utgjordes totalt av nästan hälften av kaninerna, och de kaniner som hölls inomhus eller frigående hade störst behov. Det fanns en skillnad i behovet av veterinärvård hos olika raskategorier, där kategorin små raser var högst representerad. Antalet kaniner som drabbades av olika typer av hälsorelaterade problem varierade, men sjukdomar kopplade till avelsrelaterad problematik utgjordes av nästan 1/3 av alla sjukdomar. Den vanligaste raskategorin att hålla var dvärgraser som hölls av nästan 60 % av alla deltagare, och den vanligaste orsaken till att välja just den raskategorin utgjordes av dess storlek. Den här studien visade att det finns faktorer i kaninägarens djurhållning som kan kopplas till sällskapskaninens välfärd i Sverige. Avgörande parametrar till detta har lyfts fram som kaninägarens erfarenhet och kunskap om kaniner, hållning och inhysning, samt val av raskategori. Nyckelord: Oryctolagus cuniculus, sällskapskanin, djurhållning, djurvälfärd, djuravel, djuretik / The domesticated rabbit (Oryctolagus cuniculus) is today a common pet worldwide. Pet rabbits are highlighted as the third most popular pet in Sweden, after dogs and cats. Despite this, only a very small proportion of the overall research in the subject of health and welfare deals with rabbits. This study has examined the impact on the companion rabbit's welfare of rabbit owners with or without previous experience, disease picture, and rabbit owners' preferences - and whether these are factors that affect the companion rabbit's welfare in Sweden. The study was conducted as a survey, answered by 147 participants living in Sweden. The survey was published in the network service Facebook and found available during the period 23 April - 7 May, 2021. More than 50% of the participants lacked experience and knowledge about rabbits before acquiring their first rabbit. Over 37% kept their rabbits alone, and more than 21% housed their rabbits in cages. The need for veterinary care accounted for a total of almost half of the rabbits, and the rabbits kept indoors or free-running were most in need. There was a difference in the need for veterinary care in different breed categories, where the category small breeds was most represented. The number of rabbits suffering from various types of health-related problems varied, but diseases linked to breeding-related problems accounted for almost 1/3 of all diseases. The most common breed category to keep was dwarf breeds held by almost 60% of all participants, and the most common reason for choosing that particular breed category was its size. This study showed that there are factors in the rabbit owner's animal husbandry that can be linked to the companion rabbit's welfare in Sweden. Decisive parameters for this have been highlighted as the rabbit owner's experience and knowledge of rabbits, posture and housing, as well as the choice of breed category. Keywords: Oryctolagus cuniculus, companion rabbit, animal husbandry, animal welfare, animal breeding, animal ethics

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping. In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced by reciprocation mixing to decrease pumping costs and the risk of media clogging. Three packed-bed digesters containing walnut shells as media were constructed at the on-campus dairy and studied for about six months. Over that time, several organic loading rates (OLRs), measured as both chemical oxygen demand (COD) and volatile solids (VS) were applied to the new packed-bed digesters to allow modeling of methane production. The influence of temperature on methane production was also investigated. Additionally, the study measured solids accumulation in the walnut shell packed-bed as well as the effectiveness and durability of walnut shells as packing media. Finally, a simple economic analysis was developed from the methane model to predict the financial feasibility of packed-bed digesters at flush water dairies under similar OLR conditions. Three methane production models were developed from organic loading: saturation-type (following the form of the Monod equation), power and linear. The models were evaluated in terms of regression analysis and the linearity of experimental to predicted methane production. The best model was then chosen to develop the economic predictions. Economic predictions for packed-bed digesters were calculated as internal rate of return (IRR) using the methane models along with additional input variables. Comparisons of IRRs were made using electric retail rates of $0.10 to $0.20 per kilowatt-hour and capital cost subsidies from zero to 50%. Sludge accumulation in the packed-bed was measured via change in porosity, and walnut shell durability was measured as the change in mass of representative walnut shells over the course of the study. The linear-type model of methane production from volatile solids OLR best represented this data set. Digester temperature was not found to influence methane production in this study, likely due to the small daily average ambient temperature range experienced (14°C to 24°C) and the greater influence of organic loading. Porosity of the walnut shell packed-bed decreased from 0.70 at startup to 0.34±0.06 at the end of the six-month study, indicating considerable media fouling. Sludge accumulated in each digester from zero at startup to 281±46 liters at termination. Walnut shells in the packed-bed lost on average 31.4±6.3% mass during the study period which may be attributed to degradation of more readily bio-degradable cellulose and hemi-cellulose within the walnut shells. Given the predicted methane production and media life, at present, the economic outlook for packed-bed digesters at commercial dairies is quite dependent on utility electrical rates, available subsidies and future improvements to packed-bed digester technology. The predicted IRRs ranged from below 0% (at 0% capital subsidy and $0.10/kWh) up to 25% (at 50% capital subsidy and $0.20/kWh) at large dairies (3000 milking cows). Increases in organic loading were not shown to necessarily increase IRR, particularly at OLRs above 10 g/Lliquid-d (as COD or VS). Ultimately, to better assess the value of packed-bed digesters for flush dairies, additional study is needed on topics such as sludge accumulation prevention, long-term walnut shell degradation, dairy barn flush water mixing, and more detailed economic analysis.