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Applying the SF6 tracer gas methodology to measure enteric methane emissions in grazing Brahman heifers
No full textContext. Sulfur hexafluoride (SF6) is a non-toxic, synthetic gas, which is used as a chemical tracer to contextualise the source of other gases. In livestock research, the SF6 tracer gas technique is regaining favour as a useful, viable, and robust approach to measuring enteric methane emissions, especially when respiratory chambers are not an option. This paper outlines the methodology used by the authors as part of a concept exploration study assessing the potential of using the saliva microbiome as a proxy for the rumen microbiome and thus an indicator of methane emissions. In this context, the SF6 technique was implemented to measure enteric methane emissions from tropical beef heifers in a grazing system. Aims. To facilitate the use of the SF6 technique by others, this paper describes its implementation for Brahman heifers in a grazing system, emphasising its practical adaptation for long-term use under tropical conditions with Bos indicus cattle and methodological insights gained over a full reproductive cycle. Methods. This paper describes the methodology applied by the authors, emphasising important lessons learned regarding five critical points of this technique. First, cattle were trained to wear the sampling gear imported from Institute of Animal Science (IZ, Instituto de Zootecnia), São Paulo, Brazil. Second, permeation tubes charged with appropriate SF6 amounts were manufactured, calibrated, and deployed. Third, the sampling gear was optimised for grazing conditions and the size of the cattle. Fourth, the gas sampling procedure, including sampling background SF6 from the environment, was standardised. Fifth, the gas chromatography method for measuring methane and tracer amounts of SF6 was optimised. Key results. Training of the animals is an essential step that should always be considered when implementing the SF6 technique. Subsampling the gas from canisters into glass vials for analyses should be conducted open air to avoid contamination issues. Inside the rumen, permeation tubes have a shelf life. Conclusions. Having all the components of this methodology in-house facilitated the process ofimplementing the methodology,supported by collaborationswith researchers at IZ and Agriculture Victoria who were already experts in this methodology. Implications. Now that the SF6 technique is readily available at Gatton, through QASP and the analytical facility, further research can be conducted on the methane emissions of cattle raised under tropical conditions, expanding the applicability of this approach to grazing Bos indicus heifers measured through their first pregnancy cycle
Multi-model-based validation of multi-environment trial results in horse gram (Macrotyloma uniflorum Lam. Verdc.)
No full textAnalysis of genotype-by-environment interactions (GEI) is critical for evaluating the yield and stability of genotypes in multi-environment experiments (METs). Either fixed models (AMMI and GGE biplots) or random effect models (Linear mixed models: LMM) are utilised to estimate GEI. From our preliminary METs using fixed models, a few potential horse gram mutant genotypes (G1, G3, G25, & G27) were identified. To validate this finding, confirmatory METs were performed during the 2023 (E1, E2, & E3) and 2024 (E4, E5, & E6) cropping seasons using LMM and the yield relative to the environmental maximum (YREM) index at pulses experimental farm, Coimbatore (E1 & E4), sugarcane research station, Melalathur, Vellore (E2 & E5), and farmer's field, Krishnagiri (E3 & E6). The traits positively and significantly correlated with yield were utilized for LMM and YREM analyses. The YREM value ranged from 0.55 to 1.00. The genotype G1 exhibited the highest YREM of 1.00, indicating that the crossover GEI effect did not affect its yield potential. After the likelihood ratio test (LRT), BLUP analysis was performed and identified the promising genotypes G1, G3, G22, G25, G27, and G8 based on higher predicted mean values. The genetic variance components (GVC) estimation showed low R-2 GEI (0.056 to 0.539), high 'As' (0.993 to 0.785), low to high rge (0.127 to 0.758), and medium to high H2 (0.068 to 0.863). The WAASB biplot identified potential genotypes (G1, G8, G27, G22, and G3) based on yield potential and stability. The multi-trait selection index (MTSI) recognized the genotypes G1 (1.192), G22 (1.250), G3 (1.319), and G8 (1.841) as superior performers. The combined YREM and LMM results revealed the significant breeding potential of G1, G3, G22, G27 and G8 for exploitation, while G22, G25, and G8 exhibited method-specific superiority. The selection differential analysis affirms the superiority of these genotypes for the tested traits (NC-25.70%, NPC-14.20%, NP-28.80%, NS-9.94%, YD-30.40%, & DM-0.05%). In conclusion, the validation METs reveal a slight variation among the findings between fixed and random effect models, emphasising the importance of integrating multiple analytical approaches for an effective GEI analysis in horse gram
Farmer attitudes and motivation affect their health-seeking behavior in relation to mastitis in dairy cows-A survey on Swedish dairy farms with automatic milking systems
No full textFarmers play a key role in mastitis management, particularly in deciding whether and when to contact a veterinarian or initiate treatment. This cross-sectional study aimed to investigate how herd udder health status (measured as average herd SCC), relates to farmers' health-seeking behavior, and how this behavior is influenced by farmers' herd-level udder health perception, perceived control, motivational values, and production system (organic vs. conventional). A survey was distributed to 697 Swedish dairy farmers using automatic milking systems, with 244 complete responses and 164 included in the final analysis. Farmers were presented with 3 mastitis scenarios and categorized into 4 groups based on their treatment intentions. With the self-regulation model of illness as a theoretical framework, we applied a serial multiple mediator model to explore the relationships between objective herd health, psychological constructs, and treatment behavior. Results showed that average herd SCC was not directly associated with farmers' treatment decisions. Instead, herd-level udder health perception, perceived control, and both economic and noneconomic motivation significantly influenced health-seeking behavior. Among organic farmers, perceived control and economic values had a direct effect, although no significant pathway was found among conventional farmers. These findings highlight the importance of addressing farmers' subjective perceptions and motivations in advisory strategies to improve mastitis management and animal welfare outcomes
Sensory aspects of products based on the landrace cereal swidden rye (Secale cereale)
No full textConsumer trends are shifting toward local and regional produce, particularly those with historical significance, such as landrace cereals. Increasing the production and consumption of landrace cereals has been identified as a key component of sustainable food systems. Furthermore, landrace cereals show promise for the development of healthy and gastronomically appealing products. Currently, the use of landrace cereals in commercial products is limited, which in turn affects their availability to consumers. By the use of sensory methodology, both analytical sensory and hedonic methods, this study aims to investigate the sensory characteristics of the landrace swidden rye (Secale cereale). Swidden rye from various Swedish farms, along with conventional rye, was included in the study and analysed both as flour and as baked sweet goods. The results revealed significant variations among the flours, primarily in texture and appearance. Overall, all samples exhibited a rye aroma, a grey to golden hue, firm texture, rye flavour, and a slightly bitter taste. The addition of fat and sugar amplified the differences among the samples, particularly in flavour. Consumers evaluated all baked sweet goods positively, with most significant differences in preference observed between the conventional rye and the swidden rye samples. A focus group provided further insights into preferred attributes, such as buttery, roasted, nutty, and brittle characteristics. Notable sensory differences were found among the samples when evaluated both as flour and as baked goods. The addition of butter and sugar altered the sensory profiles and their intensities. The differences observed among the swidden rye varieties may be attributed to factors such as origin, climate conditions, or agricultural practices
Assessing Sperm Quality Parameters in Mass-Spawning Norwegian Arctic Charr
Get PDFGaps in knowledge exist regarding sperm quality in farmed fish and its variation with age. The literature shows differing results among populations with diverse genetic backgrounds. Data collected from captive mass-spawning Norwegian Arctic charr were analysed to investigate sperm quality parameters and their age-related variations. We conducted a retrospective review of 63 milt analysis records from broodfish aged 2-9 years. Sperm motility and kinetic parameters decreased significantly (p < 0.05) with advancing age, whereas no significant changes were observed in sperm concentration. A regression model explaining approximately 30% of the variation (adjusted R-2 approximate to 0.3) suggested a significant and negative effect of age on sperm swimming velocities (p < 0.05). Finally, the analysis of the ddRAD data did not reveal significant genetic associations. Overall, this study provides valuable insights into age-related trends and may serve as a foundation for further investigations into the sperm quality performance of populations with varying reproductive strategies and genetic structures
Implications of low temporal resolution of vessel tracking systems
Get PDFSpatial and temporal fishing effort (FE) estimates are crucial for informing scientific-based decisions in fisheries management, spatial planning, and conservation. Lower temporal resolution (longer intervals between vessel position registrations) reduces FE accuracy, thus calling for a balance between precision and feasibility for large-scale mapping, such as in European waters. Effective marine management is critically dependent on this kind of accurate, comprehensive, and appropriate data. New EU legislation mandates tracking all fishing vessels, including small-scale fisheries (SSF) (LOA <= 12 m), implying a reassessment of optimal polling intervals. While experts recommend high-frequency polling (1 poll/30 s) for SSF, large-scale fisheries (LSF) have been mapped with up to 2-h polling intervals. Here, our study evaluates how polling frequency affects fishing activity characterization and FE estimation across fleets. We found that low temporal resolution critically affects (1) FE by underestimation, (2) misclassification of fishing behaviour, (3) compliance challenges, (4) marine spatial planning conflicts, (5) seafloor impact assessment (6) inaccurate bycatch risk analysis, (7) geographic projection biases, and (8) CPUE-based abundance indices, affecting stock and mortality estimates. These results highlight a central problem: low-resolution tracking compromises the scientific and management of outputs. The promise of high-resolution tracking to improve accuracy, is affected by the trade-offs between cost and data processing capacity, and the burden on vessel operators. Thus, SSF and passive gears should be tracked with at least a 30-s polling frequency as a conservative approach. For LSF using active gears, further work is required to determine the optimal ping frequency, but overall, it should be on the scale of a few minutes, depending on the gear used. To address this, our work clearly supports a recommendation for future regulations to define minimum acceptable polling intervals, tailored by fleet segment, and that support mechanisms be implemented to ease adoption. These regulatory aspects should contemplate a close collaboration with the fishing industry to ensure practicality, compliance, and long-term success. Thus, our findings highlight the costs of low-resolution tracking, providing critical insights for decision-makers shaping future vessel monitoring policies
Urine-derived solids as nutrient sources to enhance microbial wood degradation in a composting environment
Get PDFHuman urine and woody biomass are two abundant biological resources that can be co-valorized through biological wood oxidation (BWO), a meso-thermophilic composting process that generates low-temperature heat and nutrient-rich soil amendment. Here, we investigated the potential of three urine-derived solid formulations as nutrient supplements to enhance microbial wood degradation at 40 °C: phosphoric acid-dehydrated urine (PDU), oxalic acid-dehydrated urine (ODU), and struvite. Among these, PDU achieved the highest wood dry mass loss (27.5 % after 42 days) and oxygen consumption, with its effectiveness attributed to greater phosphorus availability, biochemically stabilized urea that gradually hydrolyzed in situ, and a sustained mildly acidic pH, conditions which collectively supported fungal colonization and carbohydrate degradation in wood. In contrast, struvite exhibited low solubility, high alkalinity, and an unfavorable N/P ratio (0.4) that limited nutrient availability and suppressed microbial activity, resulting in minor wood degradation. Complementary experiments with synthetic nutrient solutions showed that N supplied as urea was more effective than its hydrolyzed products (ammonium bicarbonate and ammonium hydroxide) and ammonium sulfate, likely because it released ammonium gradually and buffered pH shifts during composting. These findings highlight the potential of integrating acid urine dehydration with BWO as a means to advance nutrient circularity and energy sustainability
Dark brooders during rearing affect fearfulness but not production parameters of broiler chickens
Get PDFDark brooders are often suggested as enrichment for broiler chickens because they promote natural motivated behaviors compared to conventional barren environments in broiler production. Although the use of brooders is thought to convey benefits for animal welfare, it is not well described how they might affect parameters related to production and health. The objective of this study was to investigate if providing dark brooders affects production, health, behavior, and welfare compared to a control group without dark brooders. Six pens of each treatment were used, keeping 60 mixed-sex chickens (Ross 308) per pen for a full rearing period of 35 days. Data on growth, mortality, gait score, litter quality, infectious bronchitis virus (IBV)-specific antibody titers, and fearfulness were collected. There were no differences in BW at day 35 (brooders: 2857.3 ± 40.8 g, control: 2831.9 ± 39.6 g, p = 0.55) or feed conversion ratio (FCR) (brooders: 1.44, control: 1.45, P = 0.87). Nor were there any differences in mortality, gait score, or litter quality (P > 0.05). However, birds reared with brooders showed lower IBV titers compared to the control at 15 days after vaccination (P = 0.0448), although there were no other differences between treatments at 0, 22, or 29 days after vaccination. Chickens reared with dark brooders were less fearful as shown by shorter latency to first head movement in the tonic immobility test (brooders: 197.2 ± 15.9 s, control: 307.6 ± 17.9 s, P = 0.0002), shorter latency to turn itself around in tonic immobility test (brooders: 234 ± 19.7 s, control: 351 ± 29.5 s, P = 0.0012), more chickens near the object in the novel object test (brooders: 2.6 ± 0.25 birds, control: 1.5 ± 0.16 birds, P
A Comprehensive Ecotoxicological Evaluation of a Treated Olive Mill Wastewater and Obtained Sludge
Get PDFOlive mill wastewaters (OMWWs) are an environmental problem in the Mediterranean region, and it is crucial to explore strategies for their treatment and repurposing. The chemical precipitation technique (CPT) has been presented as a cost-effective wastewater treatment solution that might be applied to OMWW. The CPT-resulting precipitant subproducts (sludge) may be reprocessed (e.g., agricultural fertilizer and/or soil amendment), while the treated wastewater may be repurposed or reused (e.g., irrigation, aquaponic, or industrial processes). This study aimed to evaluate the efficacy of CPT in treating wastewater from the olive oil industry from an ecotoxicological perspective. Additionally, to assess the safe use of the obtained sludge in CPT treatment, its effects on soil biota were assessed. For this, a set of ecotoxicological assays using freshwater (Raphidocelis subcapitata, Daphnia magna and Danio rerio), terrestrial invertebrates (Folsomia candida and Enchytraeus crypticus), and plants (Brassica oleracea and Lolium perenne) were used as model organisms. Results demonstrated that CPT reduced OMWW toxicity to freshwater organisms, offering a favorable outlook on CPT's potential as a wastewater treatment method. Increasing application rates of sludge in soil reduced the shoot biomass and the hydric content of both plants compared to the control. Survival of F. candida and E. crypticus was not affected by sludge in soil at any tested application rate, yet sludge application negatively affected the reproduction of both species, even at relevant sludge application rates (2%) of sludge in soils. Overall, the applicability of this sludge obtained by the CPT treatment in soils should be carefully evaluated due to the observed adverse effects on soil biota. Although the results of CPT were promising in reducing the toxicity of OMWW for these aquatic species, some adjustments/improvements should be performed to improve this technique and use all the obtained resources (treated water and sludge) in a fully circular perspective