| 1. |
- Johnsson, Anna-Ida, et al.
(author)
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Specific SCAR markers and multiplex real-time PCR for quantification of two Trichoderma biocontrol strains in environmental samples
- 2011
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In: BioControl. - : Springer Science and Business Media LLC. - 1386-6141 .- 1573-8248. ; 56, s. 903-913
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Journal article (peer-reviewed)abstract
- Several strains from the genus Trichoderma (Ascomycetes, Hypocreales) are commercially used as biocontrol agents, e.g. in formulations containing the two Trichoderma strains IMI206039 (Hypocrea parapilulifera B.S. Lu, Druzhinina & Samuels) and IMI206040 (T. atroviride P. Karst). To quantify the presence of the two isolates after application, we developed primers for SCAR markers (Sequence-Characterised Amplified Region). In order to quantify both fungal strains simultaneously, we also designed fluorophore-labelled probes distinguishing the two strains, to be used in combination with the SCAR primers. In incubations of two different soils, artificially inoculated and maintained under controlled conditions, the quantification through amplification with the SCAR markers in qPCR and through colony-forming units from plate counting correlated well. Further tests of the markers on samples taken from a golf green treated with a product containing both strains indicated that the two biocontrol strains did not establish, either on the golf green or in the surrounding area.
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| 3. |
- Von Rosen, Dietrich
(author)
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Non-negative estimation of variance components in heteroscedastic one-way random-effects ANOVA models
- 2010
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In: Statistics. - : Informa UK Limited. - 0233-1888 .- 1029-4910. ; 44, s. 557-569
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Journal article (peer-reviewed)abstract
- There is a considerable amount of literature dealing with inference about the parameters in a heteroscedastic one-way random-effects ANOVA model. In this paper, we primarily address the problem of improved quadratic estimation of the random-effect variance component. It turns out that such estimators with a smaller mean squared error compared with some standard unbiased quadratic estimators exist under quite general conditions. Improved estimators of the error variance components are also established.
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| 4. |
- Flysjö, A., et al.
(author)
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How does co-product handling affect the carbon footprint of milk? Case study of milk production in New Zealand and Sweden
- 2011
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In: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 16:5, s. 420-430
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Journal article (peer-reviewed)abstract
- Purpose This paper investigates different methodologies of handling co-products in life cycle assessment (LCA) or carbon footprint (CF) studies. Co-product handling can have a significant effect on final LCA/CF results, and although there are guidelines on the preferred order for different methods for handling co-products, no agreed understanding on applicable methods is available. In the present study, the greenhouse gases (GHG) associated with the production of 1 kg of energy-corrected milk (ECM) at farm gate is investigated considering co-product handling. Materials and methods Two different milk production systems were used as case studies in the investigation of the effect of applying different methodologies in coproduct handling: (1) outdoor grazing system in New Zealand and (2) mainly indoor housing system with a pronounced share of concentrate feed in Sweden. Since the cows produce milk, meat (when slaughtered), calves, manure, hides, etc., the environmental burden (here GHG emissions) must be distributed between these outputs (in the present study no emissions are attributed to hides specifically, or to manure which is recycled on-farm). Different methodologically approaches, (1) system expansion (two cases), (2) physical causality allocation, (3) economic allocation, (4) protein allocation and (5) mass allocation, are applied in the study. Results and discussion The results show large differences in the final CF number depending on which methodology has been used for accounting co-products. Most evident is that system expansion gives a lower CF for milk than allocation methods. System expansion resulted in 63- 76% of GHG emissions attributed directly to milk, while allocation resulted in 85-98%. It is stressed that meat is an important by-product from milk production and that milk and beef production is closely interlinked and therefore needs to be considered in an integrated approach. Conclusions To obtain valid LCA/CF numbers for milk, it is crucial to account for by-products. Moreover, if CF numbers for milk need to be compared, the same allocation procedure should be applied. © 2011 Springer-Verlag.
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| 5. |
- Flysjö, A., et al.
(author)
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The impact of various parameters on the carbon footprint of milk production in New Zealand and Sweden
- 2011
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In: Agricultural Systems. - : Elsevier BV. - 1873-2267 .- 0308-521X. ; 104:6, s. 459-469
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Journal article (peer-reviewed)abstract
- The carbon footprint (CF) of milk production was analysed at the farm gate for two contrasting production systems; an outdoor pasture grazing system in New Zealand (NZ) and a mainly indoor housing system with pronounced use of concentrate feed in Sweden (SE). The method used is based on the conceptual framework of lifecycle assessment (LCA), but only for greenhouse gas (GHG) emissions. National average data were used to model the dairy system in each country. Collection of inventory data and calculations of emissions were harmonised to the greatest extent possible for the two systems. The calculated CF for 1kg of energy corrected milk (ECM), including related by-products (surplus calves and culled cows), was 1.00kg carbon dioxide equivalents (CO2e) for NZ and 1.16kg CO2e for SE. Methane from enteric fermentation and nitrous oxide emissions from application of nitrogen (as fertiliser and as excreta dropped directly on the field) were the main contributors to the CF in both countries. The most important parameters to consider when calculating the GHG emissions were dry matter intake (DMI), emission factor (EF) for methane from enteric fermentation, amount of nitrogen applied and EF for direct nitrous oxide emissions from soils. By changing one parameter at a time within 'reasonable' limits (i.e. no extreme values assumed), the impact on the total CF was assessed and showed changes of up to 15%. In addition, the uncertainty in CF estimates due to uncertainty in EF for methane from enteric fermentation and nitrous oxide emissions (from soil and due to ammonia volatilisation) were analysed through Monte Carlo simulation. This resulted in an uncertainty distribution corresponding to 0.60-1.52kg CO2e kg-1 ECM for NZ and 0.83-1.56kg CO2e kg-1 ECM for SE (in the prediction interval 2.5-97.5%). Hence, the variation within the systems based on the main EF is relatively large compared with the difference in CF between the countries. © 2011 Elsevier Ltd.
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| 7. |
- Olstorpe, Matilda, et al.
(author)
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Microbial changes during storage of moist crimped cereal barley grain under Swedish farm conditions
- 2010
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In: Animal Feed Science and Technology. - Amsterdam, Netherlands : Elsevier. - 0377-8401 .- 1873-2216. ; 156:1-2, s. 37-46
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Journal article (peer-reviewed)abstract
- This Study investigated feed hygiene during airtight storage of non-dried barley grain under farm conditions. Microorganisms on the grain were sampled and quantified in seven Swedish firms throughout the storage period using culture dependent methods. The dominant lactic acid bacteria (LAB) and yeasts were identified by rRNA gene sequencing and moulds by morphological characterisation. Moisture content (MC) and pH of the grain were also monitored. It was difficult to obtain the optimal MC(0.30-0.45 g/g) that is necessary to initiate fermentation in the grain. Feed hygiene was maintained during storage of cereals when MC below 0.17 g/g. Intermediate MC (0.17-0.23 g/g) of the grains was conducive to mould growth, including growth of potential producers of mycotoxins, which can diminish feed safety and nutritional value. Enterobacteriaceae were found in all barleys, even at low MC, but their numbers were substantially decreased when the number of LAB was high. True fermentation of moist crimped cereal grains was only obtained on one farm with all initial barley MC of 0.3 g/g. Here, LAB reached high numbers during storage, whereas numbers of spoilage microorganisms that may reduce feed hygiene decreased considerably. However, the pH of the barley did not differ among farms. Storage stability in airtight stored barley may thus be the result of low oxygen tension, viz. airtight storage, and competition for nutrients by the microorganisms, rather than formation of lactic acid. At harvest, Enterococcus caccae dominated the LAB Population in five barleys and Lactobacillus fermentum at the remaining two. The dominant yeast species were Aureobasidium pullulans, Cryptococcus wieringae, Kazachstania aerobia and Rhodotorula glutinis. After storage, L fermentum was dominant among the LAB. The yeast species composition was highly diverse and differed among barleys. Among others, C. wieringae, Debaryomyces hansenii, K. aerobia, R. glutinis and Sporobolomyces ruberrimus were detected. This Study shows that the microbial population in airtight stored moist barley is highly diverse and not predictable. Thus, it may be necessary to influence the microbial population in the storage system by adding a starter culture.
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| 8. |
- Olstorpe, Matilda, et al.
(author)
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Pichia anomala yeast improves feed hygiene during storage of moist crimped barley grain under Swedish farm conditions
- 2010
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In: Animal Feed Science and Technology. - Amsterdam, Netherlands : Elsevier BV. - 0377-8401 .- 1873-2216. ; 156, s. 47-56
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Journal article (peer-reviewed)abstract
- Preservation of moist crimped cereal grain is made feasible through fermentation by lactic acid bacteria. Climatic variations make it difficult to harvest at moisture contents (0.30-0.45g/g) to support optimal fermentation under practical conditions. Therefore, the yeast, Pichia anomala J121, previously found to prevent mould spoilage and improve preservation of moist grain in malfunctioning airtight silos, was added to moist crimped cereal grain stored in large plastic tubes. Freshly harvested barley grain was crimped and inoculated with P. anomala (105 colony-forming units/g grain). Due to the local weather conditions, harvest was delayed and moisture content in the cereal grain had decreased to 0.16-0.18g/g. P. anomala was inoculated into three batches of barley, each comprising 16tonnes packed into large plastic tubes. Three additional sets of plastic tubes were packed with cereal grain without addition of P. anomala. The grain tubes were left closed for 5 months, after which feeding to cattle commenced. In both the P. anomala inoculated and the control barley, the population diversity of lactic acid bacteria (LAB) was very high over the duration of storage. However, the dominant LAB shifted over the course of storage to Pediococcus pentosaceus and Lactobacillus paracasei, in inoculated and control barley, respectively. The yeast population in the inoculated barley was totally dominated by P. anomala during the entire storage period. In the control grain, the yeast population was more diverse, displaying shifts in the dominant species during storage. Pichia burtonii was the dominant species at the last sampling occasion. In P. anomala inoculated barley, numbers of naturally occurring moulds were reduced by about two log units, and the number of Enterobacteriaceae was reduced to below detection.
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| 9. |
- Henriksson, Maria, et al.
(author)
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Variation in carbon footprint of milk due to management differences between Swedish dairy farms
- 2011
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In: Animal. - 1751-7311 .- 1751-732X. ; 5:9, s. 1474-1484
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Journal article (peer-reviewed)abstract
- To identify mitigation options to reduce greenhouse gas (GHG) emissions from milk production (i.e. the carbon footprint (CF) of milk), this study examined the variation in GHG emissions among dairy farms using data from previous CF studies on Swedish milk. Variations between farms in these production data, which were found to have a strong influence on milk CF, were obtained from existing databases of 1051 dairy farms in Sweden in 2005. Monte Carlo (MC) analysis was used to analyse the impact of variations in seven important parameters on milk CF concerning milk yield (energy-corrected milk (ECM) produced and delivered), feed dry matter intake (DMI), enteric CH4 emissions, N content in feed DMI, N-fertiliser rate and diesel used on farm. The largest between-farm variations among the analysed production data were N-fertiliser rate (kg/ha) and diesel used (l/ha) on farm (CV = 31% to 38%). For the parameters concerning milk yield and feed DMI, the CV was approximately 11% and 8%, respectively. The smallest variation in production data was found for N content in feed DMI. According to the MC analysis, these variations in production data led to a variation in milk CF of between 0.94 and 1.33 kg CO2 equivalents (CO2e)/kg ECM, with an average value of 1.13 kg CO2e/kg ECM. We consider that this variation of ±17%, which was found to be based on the used farm data, would be even greater if all Swedish dairy farms were included, as the sample of farms in this study was not totally unbiased. The variation identified in milk CF indicates that a potential exists to reduce GHG emissions from milk production on both the national and farm levels through changes in management. As milk yield and feed DMI are two of the most influential parameters for milk CF, feed conversion efficiency (i.e. units ECM produced/unit DMI) can be used as a rough key performance indicator for predicting CF reductions. However, it must be borne in mind that feeds have different CF due to where and how they are produced. © 2011 The Animal Consortium.
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| 10. |
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