540 research outputs found

    Effect of raw sunflower seeds on goat milk production in different farming systems

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    Aim of this study was to test the effect of raw sunflower seeds on goat milk production. Two farms with different farming systems (intensive and semi-intensive) participated to the trial. In each farm about 60 mid-lactation Alpine goats were divided in two groups during spring-summer time. A diet containing 5-6% of sunflower seeds on DM basis was compared with a control diet in a change-over design. In the semi-intensive farm milk yield of goats fed sunflower was 3.46 kg/d compared to 3.58 kg/d of goats fed control diet, whereas in the intensive farm milk yield was 4.60 kg/d vs 4.66 kg/d. Fat content increased significantly from 2.99% to 3.23% only in the intensive farm. The research in the intensive farm investigated also milk and cheese fatty acids composition. Medium and short chain fatty acids (C8-C16) content dropped and long chain fatty acids content increased when sunflower was added. In conclusion raw sunflower seed inclusion in dairy goat diets can be useful, in order to limit the inversion of fat and protein percentages in milk

    New Avoparcin-like Molecules from the Avoparcin Producer Amycolatopsis coloradensis ATCC 53629

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    Amycolatopsis coloradensis ATCC 53629 is the producer of the glycopeptide antibiotic avoparcin. While setting up the production of the avoparcin complex, in view of its use as analytical standard, we uncovered the production of a to-date not described ristosamynil-avoparcin. Ristosamynil-avoparcin is produced together with α-and β-avoparcin (overall indicated as the avoparcin complex). Selection of one high producer morphological variant within the A. coloradensis population, together with the use of a new fermentation medium, allowed to increase productivity of the avoparcin complex up to 9 g/L in flask fermentations. The selected high producer displayed a non-spore forming phenotype. All the selected phenotypes, as well as the original unselected population, displayed invariably the ability to produce a complex rich in ristosamynil-avoparcin. This suggested that the original strain deposited was not conforming to the description or that long term storage of the lyovials has selected mutants from the original population

    Strain improvement and strain maintenance revisited. The use of actinoplanes teichomyceticus atcc 31121 protoplasts in the identification of candidates for enhanced teicoplanin production

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    Multicellular cooperation in actinomycetes is a division of labor-based beneficial trait where phenotypically specialized clonal subpopulations, or genetically distinct lineages, perform complementary tasks. The division of labor improves the access to nutrients and optimizes reproductive and vegetative tasks while reducing the costly production of secondary metabolites and/or of secreted enzymes. In this study, we took advantage of the possibility to isolate genetically distinct lineages deriving from the division of labor, for the isolation of heterogeneous teicoplanin producer phenotypes from Actinoplanes teichomyceticus ATCC 31121. In order to efficiently separate phenotypes and associated genomes, we produced and regenerated protoplasts. This approach turned out to be a rapid and effective strain improvement method, as it allowed the identification of those phenotypes in the population that produced higher teicoplanin amounts. Interestingly, a heterogeneous teicoplanin complex productivity pattern was also identified among the clones. This study suggests that strain improvement and strain maintenance should be integrated with the use of protoplasts as a strategy to unravel the hidden industrial potential of vegetative mycelium

    Environmental impact of milk production in intensive farming systems: life cycle assessment approach

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    Life cycle assessment (LCA) has been shown to be a valuable method for the environmental evaluation of farming systems and has been applied to several agricultural products, particularly in Europe. In LCA the potential environmental impacts of a product are assessed by quantifying the resources consumed and the emissions, at all stages of its life cycle, from the extraction of resources, through the production and transport of materials, to the production process at the farm. The aim of the study was to evaluate the environmental impacts of milk production in intensive farming systems using LCA approach on a sample of 44 dairy farms in northern Italy. Impact categories were: Land use, Non-renewable energy use, Climate change, Acidification and Eutrophication. Functional units were: 1 kg of Fat and Protein Corrected Milk (FPCM); 1 ha of farm land. Data were collected by personal interview with the farmers. Farms involved in the study reared on average 145 (\ub191) cows, with a daily milk production of 28.0 (\ub13.32) kg FPCM/cow. Average farm land was 49.9 (\ub137) ha and stocking density 5.3 (\ub12.5) LU/ha. On average, 59% of the total dry matter of cow rations consisted of feed ingredients produced on the farm. The average results for the 5 LCA categories per kg of FPCM were: 2.84 (\ub11.02) m2 for Land use, 4.98 (\ub11.34) MJ for Energy use, 0.93 (\ub10.29) kg CO2-eq for Climate change, 18.2 (\ub14.2) g SO2-eq for Acidification and 12.0 (\ub13.1) g PO4-eq for Eutrophication. Impact indicators from this study are similar to those reported in recent European LC analyses on intensive dairy farms, although the comparison among LCA studies from different countries can be misleading because of local peculiarities and different methodologies. Within the study, LCA indicators allowed to compare environmental impacts of milk production among farms characterized by different levels of intensification (stocking density, milk production, feed self-supply)

    A radio continuum survey of the southern sky at 1420 MHz. Observations and data reduction

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    We describe the equipment, observational method and reduction procedure of an absolutely calibrated radio continuum survey of the South Celestial Hemisphere at a frequency of 1420 MHz. These observations cover the area 0h < R.A. < 24h for declinations less than -10 degree. The sensitivity is about 50 mK T_B (full beam brightness) and the angular resolution (HPBW) is 35.4', which matches the existing northern sky survey at the same frequency.Comment: 9 pages with 9 figures, A&A, in pres

    Caracterización y cartografía fitoclimáticas del bosque nativo subantártico en la Isla Grande de Tierra del Fuego (Patagonia, Argentina)

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    Isla Grande de Tierra del Fuego is especially peculiar in phytoclimatic terms, situated as it is at an extreme southerly latitude, surrounded by large water masses and close to the great mass of Antarctic ice. Its main peculiarities in this sense are the coolness of its summers and a very narrow temperature range. As a result, the woodland landscapes in the parts with forest cover are dominated by microphyllous broadleaf physiognomies, both evergreen and deciduous, of the Nothofagus genus. This paper reports a more in-depth investigation of the hitherto little-known phytoclimatic conditions in that territory which included calibration and validation of a model of phytoclimatic suitability that addresses the principal plant physiognomic units and phytoclimatic mapping. It discusses the causes behind the presence of broadleaf formations in thermal conditions which in the northern hemisphere would allow only coniferous formations or no tree formations at all, and also the edaphic peculiarities that may explain the presence of a evergreen species like Nothofagus betuloides in subantarctic mixed forests.La Isla Grande de Tierra del Fuego presenta una muy marcada originalidad fitoclimática por su posición en latitudes muy australes, estar rodeada por grandes masas de agua y por su cercanía a la gran masa de hielo polar antártica. Esta originalidad se traduce en un escaso calor estival y una oscilación térmica muy reducida como principales peculiaridades, dando lugar en sus porciones arboladas a paisajes boscosos dominados por fisionomías planifolias de carácter micrófilo, tanto perennifolias como caducifolias del género Nothofagus. Este trabajo profundiza en las hasta hoy escasamente conocidas condiciones fitoclimáticas de este territorio, mediante la calibración y validación de un modelo de idoneidad fitoclimática respecto de las principales unidades fisionómicas de vegetación y el establecimiento de una cartografía fitoclimática. Se discuten las causas que provocan la existencia de formaciones planifolias en condiciones térmicas que darían lugar a formaciones aciculifolias o desarboladas en el hemisferio Norte, así como las particularidades edáficas que condicionan la presencia de la estrategia perennifolia representada por Nothofagus betuloides en los bosques mixtos subantárticos
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