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Extended lactations in multiparous dairy cows
Get PDFThe 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
A Base-Mediated Rearrangement of the Benzylic 1,5-Hexadipyridynyl Moiety
No full textA previously unrecognized base-mediated rearrangement of a benzylic 1,5-hexadipyridynyl moiety is reported. Upon exposure to base, this structural motif rearranges into a constrained vinyl-pyridine substituted cyclobutene. Computational modeling indicates that the rearrangement takes place following a route involving stepwise deprotonation, shifted reprotonation, and 4 pi-electrocyclization. The reaction rate and the stereochemical outcome is consistent with the experimental observations. Furthermore, nonbase mediates rearrangements, through well-known Cope-like [3,3]-sigmatropic shifts, are found to be high in energy, and therefore, take a backseat to the base-mediated pathway. This rearrangement may provide a novel reactivity pathway of conjugated systems for synthetic methodology development
Salinity adaption and toxicity of harmful algal blooms in three bays of Great Salt Lake (USA)
No full textCyanobacterial blooms can be harmful to animals and humans exposed to their toxins; however, their environmental drivers and boundaries still need to be elucidated. Salinity has been demonstrated to be an important driver of community composition that sets boundaries of species migration and survival. The filamentous cyanobacteria Nodularia spumigena forms dense blooms in estuaries around the world, produces the hepatotoxin nodularin, and has been thought to not survive or fix nitrogen (N) in high salinities. From 2005-2009 we studied three bays of Great Salt Lake (USA), two of which are estuaries with salinities ranging from 0 to >90 g l(-1) while the third, Gilbert Bay, had a salinity near 160 g l(-1). Bear River Bay and the larger Gilbert Bay were meso-eutrophic, while Farmington Bay, which receives direct inputs of secondary-treated sewage, was hypereutrophic with mean chlorophyll concentrations of 149 mu g l(-1) and dense blooms of N. spumigena. Cell densities were >500 times those of Nodularia studied in the Baltic Sea. In Farmington Bay blooms occur at salinities ranging from 8-50 g l(-1), which are much higher than usually reported for this taxon. Concentrations of the cyanotoxin nodularin reached 660 mu g l(-1) (mean = 41 mu g l(-1)), far above critical thresholds for contact recreation and above those causing bird mortalities elsewhere. The mean N-2 fixation rate of Nodularia measured over a salinity range of 14 to 52 g l(-1) was 47 mg N m(-2) d(-1), which is among the highest reported values for freshwater and marine ecosystems. The local adaptation of Nodularia to the extreme salinity conditions in Great Salt Lake furthers our understanding of salinity adaptation and the potential spread of this species to new regions
Objective measurements of skinfold thickness with a caliper show a significant relationship to total body fat percentage in dogs
No full textObjective New clinical evaluation methods for estimation of total body fat percentage (BF%) in dogs are needed. The methods should be objective and reliable for accurate assessment of body composition status and to improve prevention and treatment of obesity. The aims of the study were therefore to investigate the intra- and inter-observer reliability of objective measurements of skinfold thickness with a caliper and to explore the relationship of skinfold thickness to dual-energy X-ray absorptiometry (DEXA) BF% in dogs.Methods Twenty-three carcasses of dogs euthanatized for reasons unrelated to the study were evaluated for body condition score (BCS), bodyweight, skinfold thickness, and DEXA BF%. The results from the latter were taken as gold standard for BF% measurement. The cohort consisted of 14 different breeds, aged >= 1 year. Objective measurements of skinfold thickness were collected in triplicate by two blinded observers at the locations of the "dorsal neck," "axillar rib," and "lumbar back." Statistical analyses explored intra-class correlation coefficients (ICCs) and relationships by linear models and generalized additive models (GAMs).Results The dogs had a BCS of 2-9/9, a bodyweight of 2-52 kilograms, and a BF% of 6.4-74.7 percent. Objective measurements of skinfold thickness showed high intra- (range 0.991-0.993) and inter- (range 0.937-0.977) observer reliability at all locations. The skinfold thickness of the "axillar rib" in interaction with bodyweight within a spline (p = 0.0001), plus the "dorsal neck" as a linear variable (p = 0.0004), explained 73.4% of the variation in DEXA BF%. The BF% of small-sized dogs were over- and under-predicted by the prediction equation to a larger extent than for dogs of larger sizes. Due to the interaction with bodyweight, a slight variation in the low measurement values of the skinfold thickness corresponded to a large variation in DEXA BF%.Conclusion Objective measurements of skinfold thickness could be assessed with high reliability with a caliper and showed a significant non-linear relationship to DEXA BF%. Longitudinal clinical studies with larger cohorts of small-, medium-, and large-sized dogs of different breeds and BCS are warranted, to evaluate the caliper device for its potential to follow changes of BF% over time. Objective measurements of skinfold thickness may in the future be practically implemented in nutritional assessments of dogs
Veterinary echocardiographers' preferences for image selection, timing, and caliper placement for left atrial two-dimensional size assessment in dogs: the BENEFIT project
No full textIntroduction/Objectives: This study aimed to investigate veterinary echocardiographers' preferences for assessing left atrial (LA) size in dogs using linear two-dimensional echocardiography, focusing on image selection, timing, caliper placement, and thresholds used for LA enlargement. A secondary aim was to explore the impact of experience and training on echocardiographers' linear two-dimensional measurements of LA size in dogs. Animals, Materials and Methods: A global online study was conducted, asking veterinary echocardiographers to measure LA size using static echocardiographic images. Results: A total of 533 echocardiographers (63% non-specialists and 37% specialists, of which 43% were cardiology board certified) completed the study. Most echocardiographers (86%, n = 459/533) used a right parasternal short-axis (RPSAX) view for LA and aortic (Ao) measurements. Of these, 57% (n = 261/459) favored the same image angulation for performing measurements and 76% (n = 351/459) timed measurements at end-systole/early-diastole. Caliper placement near pulmonary venous inlets impacted their LA dimension measurements the most. Thirty-nine percent (n = 207/533) used right parasternal long-axis (RPLAX) views. The upper limit for LA enlargement varied across all commonly used methods. Training and experience level influenced interobserver variation for LA dimension measurements obtained from a RPLAX four-chamber view, but not from a RPSAX view. Study Limitations: Static images may not reflect real-time clinical settings or allow precise identification of anatomical structures. Conclusions: The RPSAX view was most favored for LA size assessment in dogs, but variations existed in image selection, timing, caliper placement, and threshold used for LA enlargement. Training and experience level influenced interobserver variation in LA dimension measurements obtained from a RPLAX four-chamber view. (c) 2025 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
On diabetes mellitus
No full textDiabetes mellitus (DM) is a common endocrine diseases in cats. Although treatment may offer a favourable prognosis and a potential for remission, disease management often encompasses challenges. The overall aim of this thesis was to broaden the understanding of DM in cats and contribute to an improved clinical management, including aspects related to the cat, the owner, and to the veterinarian. A questionnaire sent to owners of cats with DM contributed with information on clinical outcomes and owner experiences. Eating predominantly a commercially available wet diet increased odds of remission, and remission was associated with a better quality of life of the cat. Difficulties and worries associated with DM management were common among owners. Interviews demonstrated that both owners and veterinarians considered the cat’s quality of life as central, and this, together with a strong sense of responsibility, guided reasoning around the cat’s DM and treatment. Clinical decision-making was influenced by the human-cat relationship, moral values, veterinary-owner communication and other contextual factors. Finally, hair cortisol concentration (HCC) was evaluated as a biomarker of long-term hypothalamic–pituitary–adrenal (HPA) axis activity and stress. Cats with chronic disease, including DM, had higher HCC than healthy cats, suggesting that disease and disease management affect HPA-axis activity. Combing demonstrated potential as a low-stress method for hair sampling. Together, the four studies provide new insights into the clinical, emotional, and ethical dimensions of DM in cats, and highlight the importance of integrating the lived experiences of owners, cats and veterinarians in DM management
Breeding for Integrated Pest Management (B-IPM): a new concept simultaneously optimising plant resistance and biocontrol
No full textPlant breeding for disease resistance typically focuses on the traits that target pathogens, although such traits may antagonise beneficial microbes, thus thwarting any opportunities for biocontrol. In this paper, we propose the concept of Breeding for Integrated Pest Management (B-IPM) which requires the simultaneous optimisation of plant traits that confer resistance to pathogens and facilitation of biocontrol agents. We tested the prospects for B-IPM by screening wild strawberry (Fragaria vesca) genotypes for resistance to the detrimental pathogens Botrytis cinerea (causing grey mould disease) and Colletotrichum acutatum (causing anthracnose disease) and facilitation of the beneficial biocontrol agent Aureobasidium pullulans. The plant genotypes showed strong variation in their resistance to the two pathogens and their ability to facilitate biocontrol. However, while the resistance of plant genotypes to both pathogens was strongly correlated, there was no correlation between this and facilitating biocontrol, suggesting that resistance and biocontrol facilitation can be independently optimised to prepare plants for pesticide-free farming
From Low-Loaded Mesophilic to High-Loaded Thermophilic Anaerobic Digestion: Changes in Reactor Performance and Microbiome
No full textThis study investigated temporal dynamics in reactor performance and microbial community structure during anaerobic digestion of sewage sludge when the temperature was changed from 37 degrees C to 55 degrees C, followed by an increase in organic loading rate (OLR). Performance instability was observed immediately following the temperature increase and in the end of the study when the OLR was 11.1 +/- 0.3 kgVS m(-3)d(-1). The specific methane production peaked at 0.31 +/- 0.06 Nm(3) kg(-1) volatile solids (VS) during thermophilic operation and when the OLR was 3.5 +/- 0.9 kgVS m(-3)d(-1). Using metagenomic sequencing, 304 species-representative genome bins (SGB) were assembled. Network analysis revealed that 186 SGB were associated with thermophilic conditions and several new species putatively involved in key reactor functions were identified. When reactor function initially stabilised, two hydrogenotrophic and one aceticlastic methanogen (Methanothermobacter spp. and Methanosarcina thermophila), the hydrolytic Coprothermobacter proteolyticus, and putative syntrophic propionate oxidisers (e.g., Pelotomaculaceae) had high relative abundance. During the peak in specific gas production, the community was dominated by one hydrogenotrophic Methanothermobacter species coexisting with syntrophic acetate oxidising bacteria (Thermacetogenium phaeum and other species). Finally, when the reaction function deteriorated due to high OLR, new hydrolytic taxa emerged and the same aceticlastic methanogen as seen during the initial acclimatisation phase returned
Fermentation characteristics and methane production of rations with high-lipid feed alternatives in vitro
No full textThis study evaluated the effects of barley and four oat cultivars differing in lipid content, including one high-oil cultivar, and the replacement of rapeseed meal (RSM) with cold-pressed rapeseed cake (RSC), on in vitro ruminal fermentation, degradability, and methane (CH4) production. An in vitro gas production experiment was conducted using a 5 × 3 factorial arrangement of treatments with four 48-h runs. Treatments included a barley mixture [22.6 g crude fat/kg dry matter (DM)] and the oat cultivars Sonja, Niklas, Perttu, and the high-oil oat cultivar Fatima (41.2, 53.7, 58.5, and 81.2 g crude fat/kg DM, respectively), each combined with three levels of RSC (0, 50, and 100 % of protein feed). The basal diet consisted of grass silage (550 g/kg diet DM). Dynamic rumen models were applied to in vitro gas data to predict in vivo CH4 production. Predicted CH4 production (mL/g DM) was 8.3, 9.0, and 12.6 % lower, respectively, for Niklas, Perttu, and Fatima compared with barley (P ≤ 0.01), and was also lower for Fatima than for Sonja and Niklas (P ≤ 0.01). Replacing RSM with RSC linearly reduced predicted CH4 production by 4.3 % (P ≤ 0.01). In vitro ruminal DM and organic matter degradability were lower for all oat cultivars compared with barley (P ≤ 0.01), and further reduced for Perttu and Fatima compared with Sonja (P ≤ 0.04). Acetate proportion was higher for Sonja, Niklas, and Perttu than for barley and Fatima (P ≤ 0.02), while propionate was higher for Perttu and Fatima than for barley, at the expense of butyrate (P ≤ 0.02). In conclusion, high-oil oats and RSC each reduced predicted in vivo CH4, with additive effects when combined. However, high-oil oats also lowered in vitro ruminal degradability. Further in vivo studies are required to evaluate effects on digestibility, CH4 production, and animal performance
Pressures on forest habitat types 9010-91F0 under the Habitats Directive (92/43/EEC) in Sweden
No full textThis report presents the Swedish Species Information Centre’s (SSIC) assessments of pressures and threats impacting forest habitat types listed in Annex 1 of Article 17 under the Habitats Directive (Council Directive 92/43/EEC) across different biogeographical regions in Sweden.Each assessment is characterized by varying types of information and thus the method used. The focus is on the assessments of two key variables: ‘scope’ and ‘influence’, following criteria outlined in a separate report (Berglund & Maňák 2025).The assessments were made during 2024-2025 on behalf of the Swedish Environmental Protection Agency. Comments are welcome and can be sent to Håkan Berglund ([email protected])