1,721,070 research outputs found
Forage quality of species‐rich mountain grasslands subjected to zero, PK and NPK mineral fertilization for decades
No full textTo maintain species‐rich swards from which forage of a high nutritional quality can be produced, it is essential to adapt grassland fertilization strategies. In this study, we investigated how different long‐term mineral fertilization treatments affect dry‐matter (DM) yield, plant species composition, and nutrient and mineral concentrations of forage from mountain grasslands. During 2 years, forage was sampled from three different long‐term fertilization experiments located at 930 (L), 1,190 (M) and 1,340 (H) m a.s.l. at different sites in Switzerland. At each site, three mineral fertilization treatments (0, PK and NPK) had been maintained for three to six decades, with two (L and M) or three harvests (H) per year. Yield, the botanical composition and concentrations of net energy, utilizable crude protein and different phenolic fractions were determined. Nutrient and mineral concentrations were also determined. For all three sites (L, M and H), unfertilized swards had lower annual DM yields (3.39, 5.17 and 2.73 t/ha) compared to PK (6.33, 7.17 and 4.44 t/ha) and NPK fertilized swards (7.69, 7.22 and 7.44 t/ha), respectively. Long‐term fertilization had little effect on the gross nutrient and phenolic composition, but forage P and K concentration increased. The decades‐long fertilization of either PK or NPK of up to 85 kg N, 80 kg P2O5 and 240 kg K2O/ha reduced plant species richness only at site H. Fertilization of PK may allow to simultaneously increase forage productivity and maintain forage quality in mountain grasslands
Feed-food and land use competition of lowland and mountain dairy cow farms
Get PDFDairy cows and other ruminants contribute to human nutrition as they are able to convert feed components containing human inedible fibre concentrations (e.g. roughage and by-products from the food processing industry) into valuable animal-sourced food. A number of crops often fed to dairy cows (e.g. soy or cereals) are however potentially edible by humans too. Additionally, land used to grow dairy cattle feed on may compete with crop production for human consumption. Two different methods to assess the competition between feed consumption of dairy cows and human food supply were thus refined and tested on 25 Swiss dairy farms. With respect to the potential human edibility of the feeds used in dairy production, the human edible feed conversion ratio (eFCR) was applied. The land use ratio (LUR) was used to relate the food production potential, per area of land utilized, with the dairy production output. Low to medium eFCR, with values ranging from 0.02 to 0.68 were found, as an average proportion of 0.74 of total DM intake consisted of roughage. In contrast, we found relatively high LUR (0.69 to 5.93) for most farms. If the land area used to produce feed for cows was used for crop production (applying a crop rotation), 23 of the 25 farms could have produced more edible protein and all farms more human edible energy. Indicator values strongly depend on the underlying scenarios, such as the human edible proportion of feeds or the suitability of land and climate for crop production. Reducing the amount of human edible feeds in dairy farming by feeding by-products from the food processing industry and improving forage quality may be suitable strategies to reduce eFCR, but relying on low-opportunity cost feeds may restrict milk performance level per cow. On farm level, improving overall efficiency and therefore using less land (especially area suitable for crop production) per kg product decreases LUR. However, the most promising strategy to mitigate land use competition may be to localize dairy production to land areas not suitable for crop production. Both methods (eFCR and LUR) should be used in parallel. They offer an opportunity to holistically evaluate the net contribution of dairy production to the human food supply under different environmental conditions and stress the importance of production systems well suited to specific farm site characteristics
Farm-gate nutrient balances of grassland-based milk production systems with full- or part-time grazing and fresh herbage indoor feeding at variable concentrate levels
No full textFarm-gate balances for nitrogen (N) andphosphorus (P) were used to determine the potentialnutrient surplus and nutrient-use efficiency of threegrassland-based milk production systems. These wereeither full-time grazing (FG) or part-time grazing withindoor feeding of fresh herbage with low (IF) orsubstantial concentrate allowance (IFplus). Data col-lected over 3 years were used (a) from 398commercial dairy farms, and (b) from a controlledexperiment. On FG, IF and IFplus farms, the N surplus(net input minus net output) was 78.6, 75.1 and 138.2kg N ha-1a-1, respectively, and N use efficiency(NUE; net output/net input) was 0.33, 0.44 and 0.34,respectively. Annual P inputs and outputs wererelatively balanced, with a higher P use efficiency(PUE) found for FG (1.19) and IF (0.97) farms than forIFplus farms (0.57). The most important input sources,apart from biological N2fixation and atmospheric Ndeposition, were mineral fertilizer N, concentrate N/Pin IFplus, and animal manure P. Results from thecontrolled experiment confirmed most of these find-ings. In general, the IF provided an efficient nutrientuse at a relatively low surplus. Accounting for off-farm losses associated with feed inputs and manureexport reduced the system NUE and PUE substan-tially. The large variability in nutrient-use efficiencyamong the commercial farms indicates a clear poten-tial for improvement. The average N surplus could bereduced by approximately 40% in reference to the bestperforming farms in each system
Allocation of environmental burdens in dairy systems: Expanding a biophysical approach for application to larger meat-to-milk ratios
Get PDFThe dairy sector is urged to reduce environmental impacts, such as greenhouse gas (GHG) emissions. But dairy farms not only produce milk: surplus calves and culled cows also yield meat as co-product. To split environmental impacts between milk and meat, a biophysical allocation method proposed by the International Dairy Federation (IDF) is currently used. Its applicability to farms with large meat-to-milk output ratios (beef-to-milk ratio, BMR) may be limited and lead to wrong conclusions when assessing GHG emissions and mitigation measures at farm level.
To overcome these limitations, we developed a biophysical allocation approach based on the net energy requirement for milk and meat production according to internationally agreed energy requirements for dairy cows. Both the enhanced and the existing allocation methods were tested on an international dataset that included farms with a large range of BMR, as can be found in dual-purpose production systems or on farms with low milk productivity. The results from the international dataset reveal that the allocation factor does not substantially change for production systems with low BMR. For BMR up to 0.03 kg live weight (LW)/kg of fat- and protein-corrected milk (FPCM), the maximum deviation in the allocation factor between the two methods was 0.047. For larger BMR, the developed method still allocated relevant shares of emissions to meat while the standard approach did not. The developed method is less sensitive to shifts in BMR, especially for low-performing dairy farms.
In addition, both methods were tested on a dataset of 46 Swiss dairy farms. By increasing the longevity of cows (one additional lactation), the impacts of altered BMR on the modelled GHG emissions and their allocation on milk and meat could be assessed. Increased longevity resulted in fewer cows to be replaced, decreased emissions from the rearing of replacement stock (-444 kg CO2-equivalents/cow/year) and lower meat output (-61 kg LW/cow/year), as fewer cows were culled. Consequently, a larger share of emissions was allocated to milk. While the standard biophysical allocation approach did not result in reduced GHG emissions per kg of milk (+0.002 kg CO2-equivalents/kg FPCM), the newly developed approach generated a modest (-0.022 kg CO2-equivalents/kg FPCM), although not significant reduction.
The effects of GHG mitigation measures that affect BMR are thus represented more accurately than when applying the standard approach. Based on the presented data, we encourage the revision of currently used international standards for allocating environmental impacts to milk and meat
Nitrogen use efficiency, reticulo-ruminal pH and behaviour of lactating cows grazing either in a full-time system or in a part-time system with indoor feeding of fresh herbage and concentrate
No full textIncreasing herd size and fragmented or non-uniform land challenge pasture-based milk pro-duction systems. Therefore, part-time grazing combined with indoor feeding of fresh herbage(‘cut-and-carry’) allows to maintain the advantages of fresh-herbage-based diets. However,consequences for environmental nitrogen losses, animal behaviour and ruminal metabolismare decisive for its implementation. Animal performance, nitrogen use efficiency (NUE), reti-culo-ruminal pH and feeding/locomotive behaviour were compared in six cows subjectedeither to full-time grazing (system F) or to part-time grazing system with indoor feeding offresh herbage and concentrate (system P). Biweekly samplings were performed on six lactatingcows per treatment in spring, summer and autumn. Nitrogen (N) balance was calculatedfrom estimated N intake and N output via faeces, urine and milk. Reticulo-ruminal pHwas recorded using a wireless data recorder. Eating and locomotive behaviour were measuredwith noseband sensors and pedometers. In spring, but not later, herbage intake per unit ofbody weight was higher for system F compared to system P cows. Eating time was shorterby 15% in P compared to F cows. Across systems, NUE declined from spring to summer/autumn from about 300 to 200 g milk protein N/kg N intake. Reticulo-ruminal pH was morevariable under part-time grazing conditions, with a pronounced decrease subsequent to offer-ing the herbage indoors. The part-time grazing system resulted in similar or higher NUE thanfull-time grazing. Additional studies with larger numbers of experimental units are required tobe able to develop comprehensive recommendations for the improvement of the two grazingsystems
Treibhausgase: KLIR – Modell zur einzelbetrieblichen Berechnung der Emissionen auf Milchviehbetrieben
Get PDFDie Schweizer Landwirtschaft verursacht rund 13 Prozent der Treibhausgasemissionen der Schweiz. Über die Hälfte davon entfällt dabei auf die Milchviehhaltung. Um Reduktionsmassnahmen auf der Stufe von Einzelbetrieben zu evaluieren, werden Bilanzierungsmodelle benötigt, welche die Produktionstechnik differenziert abbilden. In einem gemeinsamen Projekt von Aaremilch und Nestlé wurde durch die HAFL ein Modell zur einzelbetrieblichen Berechnung der Treibhausgasemissionen aus der Milchviehhaltung entwickelt. Die Berechnungsmethodik beruht auf international anerkannten Standards, die, wo möglich, für die Schweiz adaptiert wurden. Mit dem Modell wurden für 46 Milchviehbetriebe im Kanton Bern die Treibhausgasemissionen berechnet. Im Mittel der Betriebe entfallen rund 56 % der Emissionen auf die enterische Fermentation, 23 % auf die Hofdüngerlagerung und 20 % auf die Produktion von Futtermitteln. Die Treibhausgasemissionen liegen mit 1,01 kg CO2-Äquivalenten pro kg ECM tiefer als bisher für die Schweiz angenommen. Werden die Emissionen auch dem mit der Milchviehhaltung verbundenen Koppelprodukt Fleisch zugeordnet (alloziert), reduzieren sich die Emissionen in Abhängigkeit der gewählten Allokationsmethode auf 0,77 bis 0,75 kg CO2-Äquivalente pro kg ECM. Die Resultate zeigen die Bedeutung der Verwendung von betriebsspezifischen Angaben zur Produktionstechnik, um die einzelbetrieblichen Emissionen differenziert abbilden zu können und Reduktionspotenziale zu identifizieren. Die Auswirkungen möglicher Reduktionsmassnahmen werden in einem folgenden Beitrag behandelt
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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