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    A New Approach in Profile Analysis with High-Dimensional Data Using Scores
    (Swedish University of Agricultural Sciences, Department of Energy and Technology, 2020) Cengiz, Cigdem
    In profile analysis, there exist three tests: test of parallelism, test of levels and test of flatness. In this thesis, these tests have been studied. Firstly, a classical setting, where the sample size is greater than the dimension of the parameter space, is considered.  The hypotheses have been established and likelihood ratio tests have been derived. The distributions of these test statistics have been given. In the latter stage, all tests have been derived in a high-dimensional setting, where the number of parameters exceeds the number of sample size. Such settings have become more common due to the advances in computer technologies in the last decades. In high-dimensional data analysis, several issues arise with the dimensionality and different techniques have been developed to deal with these issues.  We propose a dimension reduction method using scores that was first proposed by Läuter et al. (1996). To be able to find the specific distributions of the test statistics of profile analysis in this context, the properties of spherical distributions are utilized.
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    Assessment of statistical analysis of Swedish cultivar testing: a cross-validation study for model selection
    (Department of Energy and Technology, Swedish University of Agricultural Sciences, 2019) Buntaran, Harimurti
    The Swedish official cultivar testing conducts multienvironmental trials (MET) to makerecommendations of cultivars that are well adapted to farmers’ regional conditions. Inthe MET, a large number of cultivars are tested in several geographical regions. Thetested cultivars perform differently in varying soil types and climates, a phenomenonknown as genotype×environment interactions. The MET data structure is often large andhighly imbalanced, which causes computational problems when applying some statisticalmethods. Several issues, such as prediction of crop variety performance and efficientcomputation of measure of cultivar stability are urgent to be tackled by developingcomprehensive and robust statistical methods. This study aims to address these issuesand provide a gold standard for MET analysis in Swedish official cultivar testing. In this study, we investigated several linear mixed models by using cross-validation(CV). We proposed to use random cultivar effects, known as best linear unbiasedprediction (BLUP) method to replace the current fixed cultivar effects, known as bestlinear unbiased estimation (BLUE). In theory, BLUP provides more accurate rankingsand predictions than BLUE. The current-practice analysis strategy, i.e., two-stageunweighted strategy, was also compared to several strategies such as single-stagestrategy and two-stage weighted strategies that comprise some weighting methods. In theCV, mean squared error of differences (MSEP) was used to assess the performance ofestimation of cultivar effects by BLUP and BLUE to select a model that provides bestprediction accuracy. A new inter-zone stability measure was also proposed to tacklecomputational burden and provide additional useful information regarding cultivarstability across zones and years. The MSEP revealed that BLUP outperformed the current-practice method, BLUE,and so improved the accuracy of zone-based prediction. Also, the single-stage and twostage weighted strategies outperformed the current strategy. The proposed stabilitymeasure offered a less computational resource, and provided more flexible stabilitymeasure for practical purpose.
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    Breeding of Swedish Warmblood horses towards specialization in show jumping and dressage
    (Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, 2023) Bonow, Sandra
    A clear specialization towards show jumping or dressage performance is evident in most European Warmblood studbooks. As a consequence, some breeding organizations have introduced specialized breeding programs. The aim of this thesis was to investigate the specialization towards show jumping and dressage in the Swedish Warmblood (SWB) population, as well as the relationships between linearly scored traits and performance in these disciplines. The proportion of allround horses had decreased considerably from 1980 in favor of show jumping and dressage horses. A decrease was also seen in the average relationship between show jumping and dressage horses over time, while it increased within the subpopulations during the past decade. A future scenario with discipline-specific young horse tests would result in decreased heritability and genetic variance for traits that are not assessed for all horses, but would have only minor impact on the ranking of sires within discipline based on breeding values. Phenotypic relationships between linearly scored traits and competition results showed that few traits except jumping traits were important for performance in show jumping, whereas several conformation and gait traits seemed to be of high importance for performance in dressage. For show jumping performance, most relationships had a linear association, whereas relationships with intermediate optimal scores were common for performance in dressage. The findings confirm the specialization of the SWB population, and that linear assessment of young horses is a valuable tool in sport horse breeding.
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    Cattle adaption to virtual fences in semi-natural pastures with multiple virtual borders: impact on behaviour and level of cortisol in faeces and hair in comparison to physical electric fences
    (Department of Animal Biosciences, Swedish University of Agricultural Sciences, 2024) Wahlund, Lotten
    The interest in GPS-based virtual fencing for grazing management of cattle, using audio cues combined with electric pulses, has increased in recent years. This thesis aimed to explore cattle adaptation to virtual fencing in semi-natural pastures with the relocation of multiple borders and to investigate the physiological and behavioural effects compared to traditional electric fencing. It presents results from two simultaneous studies (A and B) conducted from May to July 2022 in a seminatural pasture in Sweden. Study A examined the learning curve and adaptation of seven heifers to a virtual fence with one to four virtual borders and two relocations over six weeks. Study B compared FCM (faecal corticoid metabolite) and HCC (hair cortisol concentration) levels, behaviour, and activity between heifers exposed to either a virtual fence (VFG) or a physical electric fence (EFG) over seven weeks. Results showed that the heifers, within seven days, learned to turn at the audio cue to avoid the electric pulse and improved their adaption and management skills over time, regardless of the number and relocation of the virtual borders. The results revealed higher FCM levels in VFG at the beginning of the pasture period compared to EFG. However, this difference was evident even before the virtual fence was introduced, suggesting that the stress response might be due to unknown factors rather than the fencing system itself. This was also supported by similar HCC levels and weight changes between groups, indicating no long-term stress. Additionally, no differences in behaviour were observed that could be attributed to stress. In conclusion, the findings suggest that virtual fences can be a promising alternative for grazing management in semi-natural pastures, with a similar impact on cortisol response and behaviour compared to traditional electric fences.
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    Designed plant communities for nature-based solutions: an investigation of urban rain gardens
    (Department of Urban and Rural Development, Swedish University of Agricultural Sciences, 2025) Uppala, Ella
    Healthy and diverse vegetation is the prerequisite for “nature-based solutions” (NbS), which is a concept that describes the intentional use of designed or managed vegetation to answer to societal challenges by providing multiple ecosystem services simultaneously and efficiently. Urban rain gardens (URG) are an example of a nature-based solution where vegetation is used to improve technical function, provide amenity values, and wildlife habitat. This thesis investigates the relevance of “designed plant communities” (DPC) as a framework for designing and managing URG vegetation. The investigation consists of 1) a narrative literature review on the history, core ideas and design tools of DPC, 2) a scoping review on DPC research and its contributions to NbS criteria fulfillment, 3) semi-structured interviews on the strategic management or URG:s in Sweden and Finland, 4) designed case studies comparing four different plant selection strategies, including DPC, with regards to their short-term establishment and development, and 5) a data collection on vegetation development in URG:s in Sweden and Finland. The narrative review highlights knowledge gaps that hinder the DPC framework’s planting design tools from reliably aiding in fulfilling DPC objectives and goals. The scoping review shows that while research on DPC provides insight into urban vegetation establishment and its short-term development, it is rarely anchored in the societal challenges that NbS seek to address, and provides little evidence on how DPC provide regulating or provisioning ecosystem services. The interview results show the unpredictability of URG vegetation development, despite the innovation and effort often put into creating URG:s. The results of the case studies also indicate that while DPC-plantings can establish and perform as well as other planting design strategies in the short term, it is not an inherently successful planting design strategy. As realized performance is more important for NbS than adherence to specific design methods, developing the DPC-framework into an evidence-based planting design practice might improve design outcomes and the framework’s relevance for NbS.
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    Extended lactations in multiparous dairy cows
    (Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences, 2025) Hansson, Annica
    The substantial increase in milk yield capacity in modern dairy herds has generated interest in extending voluntary waiting period (VWP) as a strategy to prolong the calving interval (CInt). This Licentiate thesis investigated the effects of extended VWP on fertility, milk production, and culling in second-parity cows, as well as associations between CInt, milk yield in second parity and mortality during the first month after the third calving. In a randomized controlled study of 819 second-parity cows from 12 high-yielding commercial herds, cows were allocated to either a conventional (50-day) or extended (140-day) VWP. The VWP treatments resulted in calving intervals of 12.5 and 14.0 months, respectively, but had no effect on daily milk yield per calving interval day, milk yield per lactating day, or dry period length. Fertility improved in the extended VWP group, as indicated by a higher pregnancy proportion in the first service, fewer inseminations per calf and a shorter insemination period. No effect on culling rate was observed. In a retrospective cohort study, data from the Swedish Official Milk Recording Scheme was analyzed to evaluate associations between CInt and on-farm mortality after the third calving. An increased risk of mortality was detected in cows with CInt longer than 13 months. Mortality risk was also associated with high milk yield, both as a 305-day yield and as the yield at the last insemination relative to the herd average at the third test milking. In the subset of the most high-yielding herds, this difference was not statistically significant. Together, these findings indicate that an extended VWP can improve fertility in second-parity cows without compromising milk production or affecting culling rates. However, long CInt were associated with an increased risk of on-farm mortality within 30 days after the subsequent calving.
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    Impact of litter size on sow health and welfare
    (Department of Animal Environment and Health, Swedish University of Agricultural Sciences, 2018) Andersson, Emma
    Genetic improvement of litter size has been the main breeding goal in piglet production during the last decades, resulting in a steady increase in total number of born piglets in each litter both in Sweden and in other European countries. It has been suggested that large litters pose a major welfare problem for sows and piglets. However, there is a lack of recent studies investigating the impact of litter size on the health and welfare of sows. Therefore the objective of this thesis was to investigate the association between litter sizes and sow health and welfare. The two studies included in this thesis were performed as observational studies and investigated by retrospective analysis of available pig production data. The first study investigated the association between litter sizes and sow stayability, and the second study the association between litter size and medical treatment of sows during farrowing and lactation. The final dataset used in the first study included a study population of 38 878 sows in 24 herds and the final dataset in the second study included observations from 1 947 litters from 655 sows. Associations between litter size and sow health and welfare was found. There was an association between litter size and stayability of the sow, as well as association between litter size and medical treatment of the sow. The results from both studies imply that sows with medium sized litters have a better lifetime production than sows with very small or large litters. Piglet producers should therefore pay even more attention to prophylactic management of sows during gestation and lactation. In planning of breeding strategies and annual removal of sows, piglet producers should also aim for keeping sows giving birth to a medium-sized litter, with approximately 12 to 14 piglets born in total in their breeding program, as this seems to improve sows’ stayability and decreasing the risk of unplanned removal which would favour health and welfare of both sow and piglets.
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    Kursplaner bibul.1617
    (SLU, 2023) SLU bibul
    Forskarkursplaner och forskarkurstillfällen från Slukurs per läsår.
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    Kursplaner bibul.1718
    (SLU, 2023) SLU bibul
    Forskarkursplaner och forskarkurstillfällen från Slukurs per läsår.
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    Kursplaner bibul.1819
    (SLU, 2023) SLU bibul
    Forskarkursplaner och forskarkurstillfällen från Slukurs per läsår.
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    Kursplaner bibul.1920
    (SLU, 2023) SLU bibul
    Forskarkursplaner och forskarkurstillfällen från Slukurs per läsår.
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    Kursplaner bibul.2021
    (SLU, 2023) SLU bibul
    Forskarkursplaner och forskarkurstillfällen från Slukurs per läsår.
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    Kursplaner bibul.2122
    (SLU, 2023) SLU bibul
    Forskarkursplaner och forskarkurstillfällen från Slukurs per läsår.
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    Neurocognitive modelling of human decision making
    (Department of Energy and Technology, Swedish University of Agricultural Sciences, 2019) Nazir, Azadeh Hassannejad
    A central issue related to climate change and the path to a low carbon society is how we can change our attitudes and associated behavioral patterns. This type of decisions is concerned with how complex systems can be dealt with, conceptually, psychologically, as well as socially. In order to transform our society, we need to consider the relationship between brain, mind and behavior. One of the approaches to address this problem is to design computational models that can be used for simulations and scenario building. This thesis concerns the development and application of a neurocomputational model of the decision making process of an individual at experiential and social levels, considering both emotional and rational aspects. It is an attempt to bridge the gaps between micro (neuronal), meso (brain areas) and macro (cognition/behavior) levels with a focus on the mesoscale neurodynamics of cortical structures. The model is intended to link neural structures, functions, and includes effects of internal and environmental factors. The thesis is divided into two parts, corresponding to the two kinds of decision making: 1) experience-based and 2) social-based decision making. At an individual level, a final decision is the result of an integration of rational and emotional processes. The neural structures involved in cognition valuate the potential options regarding internal attitudes and rules, as well as external contexts. Decision values are based on neural properties of activity patterns associated with different actions. The option with the highest value is selected for in the decision making process. Human behavior is guided not only by subjective values and attitudes, but also by the perceived behavior of others. Learning from/about others through observation shapes our thoughts and behavioral patterns. The second part of the thesis deals with this social adaptive characteristic of an individual, where the dynamic changes of her behaviors are connected with trust. Traces of social influences on an individual’s decisions and social expectations (e.g. trust) have been observed in the rational and emotional brain structures and their functions. While the neurocomputational model is based on anatomical and physiological data of the modeled brain structures, no real world data have been available for model validation. Yet, simulation results mimic EEG and fMRI readouts, which could be compared with experimental/clinical data, when available. Future work intends to provide such data, but currently the modeling can only provide insights in the neurodynamic interactions between brain areas involved in decision making.
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    Salmonids and grey seals (Halichoerus grypus): mitigation in pontoon traps
    (Department of Aquatic Resources, Swedish University of Agricultural Sciences, 2018) Calamnius, Linda
    In the 1970’s, the seal populations of the Baltic Sea Area were at historically low levels. They have recovered and increased since then. The increase of the seal populations is a success for the management of the Baltic Sea Area environment. It has also meant an increase in number of interactions with coastal fisheries. Seals take fish and damage fishing gear. Three studies were carried out with the purpose of contributing to a sustainable fishery and fewer interactions between seals and fishers. The first study compared the effect two different Seal Exclusion Devices (SEDs) had on the catch and on seal visits. The SEDs used were a diamond mesh SED and a square mesh SED, with the frame rotated 45°. They were compared with a control, an open frame. The expectation was that using SEDs would reduce the number of seal visits, increase the catch and deter larger fish from entering. Larger salmons (Salmo salar) were caught in the traps with selection panels. For brown trout (Salmo trutta), there was no difference in size of fish between the SEDs. Neither of the SEDs had any effect on total catch or catch per unit effort. The number of seal visits were too low to be able to draw any conclusions regarding presence of seals. The second study examined the efficiency of selection panels in a pontoon trap for salmon and whitefish. One control and two experimental traps were used. The mesh in the control trap had 35 mm bar length. The selection panel was square mesh with 50 mm bar length. In one of the experimental traps, the selection panel covered 30 % of the inner netting. In the other, it covered 100 %. The results showed that proportionally more fish of commercial size were caught in traps with selection panels. Using selection panels contributes to a sustainable fishery. The third study analysed a series of visits by seals in the middle chamber of a herring pontoon trap. Visiting seals were filmed in the middle chamber. Roughly, 1 400 visits by 12 seals were recorded. Of all visits, 3.5 % were overlapping visits, i.e. two seals inside the middle chamber at the same time. Forty simulations of random visits were performed resulting in an average of 7.1 % overlapping visits. There was a significant difference between the actual overlapping visits and the simulated. This suggests that the seals avoided swimming in when another seal was present
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    Time and spatial dependent climate impact of grass cultivation and grass-based biogas system
    (Sveriges lantbruksuniversitet, Institutionen för energi och teknik, 2020) Nilsson, Johan
    One strategy to limit global warming is to phase out fossil products and replace them with bio-based alternatives. This is often referred to as transitioning from a fossil economy to a bioeconomy. In this transition, it is important to know the environmental impact of bio-based products, since it can be greater than that of the fossil products they replace. Life Cycle Assessment (LCA) is a suitable methodology for studying the impact of bio-based products, since it encompasses the whole life cycle of the product. However, LCA rarely considers spatial and temporal variations in impacts. It also rarely includes soil processes such as soil carbon balance and only roughly estimates nitrous oxide (N2O) emissions from soil.In this thesis, LCA was combined with the agro-ecosystem model DNDC to include these soil processes and their variations over time and space. The combined method was used to assess climate impact and eutrophication in grass production at five sites in central and southern Sweden and the climate impact and energy balance in grass-based biogas production in Uppsala municipality, Sweden. Analysis of grass cultivation with two fertilisation rates (140 and 200 kg N ha-1) at different Swedish sites revealed that the higher rate gave a lower climate impact per Mg harvested biomass, but that site properties were more important than fertilisation intensity in determining the climate impact.Analysis of grass for biogas production, which was assumed to be cultivated on fallow land, was conducted for more than 1000 regional sites with different properties in Uppsala municipality and the whole life cycle was included (cradle to grave). The results showed large variations in impact between different sites, depending on weather conditions, soil properties, transport distances etc. The greenhouse gas fluxes from grass cultivation with the greatest climate impact were soil N2O emissions and emissions from fertiliser manufacture, which contributed to global warming, and changes in soil carbon balance, which generally had a climate mitigating effect. Overall, grass cultivation increased soil carbon stocks, but this effect was highly site- and time-dependent. The grass-based biogas production system reduced the climate impact significantly compared with the reference fallow-diesel-mineral fertiliser system.The method developed in this thesis, where LCA was combined with agro-ecosystem modelling, could be used to assess the environmental impact of agricultural systems in other regions. The results could then also be used to assist policymakers in optimising agricultural land use planning for food, feed and fuel production.
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    UV-based advanced oxidation process for nutrient stabilisation and organic micropollutant degradation in source-separated human urine
    (Department of Energy and Technology, Swedish University of Agricultural Sciences, 2023) Demissie, Natnael
    Urine dehydration is one of the technological approach to recover nutrients in concentrated form from source separated urine. When drying fresh urine, nitrogen loss occurs due to hydrolysis of urea into ammonia unless methods to inactivate urease enzyme are employed. In addition, concerns arise when using urine-derived fertiliser due to the potential presence of organic micropollutants (pharmaceuticals). This thesis evaluated ultraviolet (UV) treatment as an alternative chemical-free nutrient stabilisation (urease inactivation) and organic micropollutant (OMP) degradation technology. Urease inactivation and OMP degradation in water and in urine (synthetic urine, real urine from human subjects) were studied in a photoreactor equipped with a low-pressure mercury UV lamp emitting light predominantly at 185 and 254 nm. Exposure of real urine to 80 min of UV irradiation resulted in more than 90% degradation of 18 out of 75 OMPs and 1-90% degradation of the remaining OMPs. Enzymatic activity fell below the detection limit for real urine exposed to 71 min of UV irradiation. However, electrical energy demand for reducing enzymatic activity below the detection limit in real fresh urine was 52-fold higher than for inactivation in synthetic fresh urine (without urea), while electrical energy demand was more than 10-fold higher for 90% OMP degradation in real fresh urine than in water. The inactivation and OMP degradation observed were probably due to direct photolysis and photo-oxidation. Presence of organic substances in real urine was the likely reason for less efficient inactivation of urease and OMP degradation, as such substances can competitively absorb incoming UV light and scavenge the free radicals formed during UV treatment. Although 20% urea was lost after UV treatment, there was no decrease in total nitrogen. In summary, UV treatment can stabilise urea-N and degrade OMPs in fresh urine and has potential for integration into urine diversion sanitation systems.
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    Wooden multi-storey construction market development in Sweden
    (Department of Forest Economics, Swedish University of Agricultural Sciences, 2023) Nagy, Emil
    The ongoing climate change is closely related to greenhouse gas emissions from industries. One of the contributors to these sustainability challenges is the house construction industry. Although residential and commercial construction is needed, the production practices needs to be altered in order to meet sustainability objectives. This licentiate dissertation focuses on conditions for wooden multi-storey construction (WMC) in a Swedish context. It explores the conditions for market development for residential WMC. The dissertation focuses on corporate perspectives, but it also integrates the role of end-consumers. A systematic literature review served as an orientation before conducting empirical case studies analysis. With an understanding of the industrial norm, currently reflected in materials such as concrete and steel, the empirical studies focused on wooden multi-storey construction case studies and end-consumer’s perceptions. These case studies indicate that a transition to WMC is hindered by path dependence, strong market positions for the currently used materials, and dated understandings of wood as a construction material. In the production process of residential construction, wood or other material, the end-consumer, the resident of an apartment in the house to be, is relatively anonymous. This is a reflection of a product dominant logic of the value chain where the end-consumer is a buyer or renter of an apartment. Enabling factors for further WMC market development that were verbalised by the case study respondents are captured in four factors: the properties of wood in a pre-fabrication setting, shorter erection times on site, fewer transports, and awareness of legislative sustainability demands. The case study interviewees report focusing on efficiency and technical properties in their business models - and limited concern for marketing communication and co-creation with end-consumers. The new legislation was seen as an enabling factor for the WMC market development by the case interviewees. It is clear that a sustainability transition, such as a gradual change to renewable construction materials that have carbon capture capacity, will take time. Business models that foster co-creation of value in public private partnerships may enable a WMC market development. The development of new legislation and increased awareness of sustainability aspects in construction is seen as future research areas for sustainable development.