1,720,958 research outputs found
Extrusion of grass silage and its effect on feed intake, milk production and ingestive behaviour of dairy cows
Get PDFGrass and clover ley is the main forage crop in Sweden, however, its restrictive role in feed intake limits the total amount included in the diet of a dairy cow. This study examined the effect of extrusion on grass silage intake, milk production, ingestive behaviour and rumen pH. Eight Swedish Red dairy cows in mid/late lactation were fed grass silage of early or late harvest, extruded or control, in a 4x4 Latin square design with four periods of three weeks. Diets were supplemented with a mix of soybean meal, compound feed and minerals. Extrusion increased daily silage dry matter (DM) intake by 1.84 kg/d (p < 0.001), neutral detergent fibre (NDF) intake by 1.04 kg/d (p < 0.001) and decreased physical effective NDF (peNDF8) intake by 1.37 kg/d (p < 0.001). Total DM intake increased by 1.74 kg/d (p < 0.001) while the dietary DM percentage of peNDF8 decreased by 6.9 units (p < 0.001). Milk yield increased by 1.32 kg/d (p = 0.008), Energy corrected milk (ECM) yield increased by 1.87 kg/d (p = 0.004), milk protein concentration increased by 0.09 percentage units (p < 0.001) while total fat and protein production increased by 72.4 g/d (p = 0.015) and 73.7 g/d (p < 0.001), respectively. Extrusion decreased average rumen pH by 0.1 units (p = 0.008). The time rumen pH was below 5.8 increased by 2.97 h/d (p = 0.038) while the curve area below this cut-off point was not affected (p = 0.166). Rate of intake of silage DM and NDF was increased by 20.3 and 11.3 g/min respectively (p < 0.001), daily silage eating time decreased by 0.6 h/d (p = 0.006) and daily rumination time decreased by 1.96 h/d (p < 0.001). Daily chewing time decreased by 2.49 h/d (p < 0.001), with rumination and chewing time per kg of silage NDF intake, decreased by 18.9 and 26.3 min/kg (p < 0.001) respectively. In conclusion, extrusion increased silage intake, eating rate and milk production but decreased chewing activity.Vall är den huvudsakliga grovfodergrödan i Sverige men vallfodrets egenskaper begränsar konsumtionen och därmed även den totala mängden som kan ingå i mjölkkons totalfoderstat. Syftet med denna studie var att undersöka hur extrudering (en metod för intensiv bearbetning och finfördelning) av vallensilage påverkar foderkonsumtion, mjölkproduktion, ätbeteende och våm-pH. Åtta SRB-kor utfodrades med gräsensilage från förstaskörd, slaget vid två tillfällen, som utfodrades hackat eller extruderat, i en romersk kvadrat med fyra behandlingar och fyra försöksperioder. Grovfodret kompletterades med kraftfoder bestående av färdigfoder, sojamjöl och mineralfoder. Extrudering ökade intaget av ensilage med 1,84 kg torrsubstans (TS) / dag (p < 0,001) och intaget av fiber (Neutral Detergent Fiber, NDF) med 1,04 kg / d (p < 0,001) medan intaget av peNDF8 (ett mått på struktureffekt som innefattar NDF-halt och partikelstorleksfördelning) minskade med 1,37 kg/d (p < 0,001). Det totala TS-intaget ökade med 1,74 kg / dag (p < 0,001) medan andelen peNDF8 i foderstaten minskade med 6,9 procentenheter (p < 0,001). Mjölkavkastningen ökade med 1,32 kg / d (p = 0,008), energikorrigerad mjölk (ECM) ökade med 1,87 kg / d (p = 0,004), mjölkproteinhalten ökade med 0,09 procentenheter (p < 0,001) medan den totala dagliga produktionen av fett och protein ökade med 72,4 g / d (p = 0,015) respektive 73,7 g / d (p < 0,001). Extrudering minskade pH-värdet i våmmen med 0,1 enheter (p = 0,008). Tiden med våm-pH under 5,8 ökade med 2,97 h / d (p = 0,038), medan kurvarean under detta tröskelvärde inte påverkades (p = 0,166). Äthastigheten för torrsubstans och NDF i ensilage ökade med 20,3 respektive 11,3 g / min (p < 0,001), den dagliga ättiden för ensilage minskade med 0,6 h / d (p = 0,006) och den dagliga idisslingstiden minskade med 1,96 h / d ( p < 0,001). Den totala tuggtiden minskade med 2,49 h / d (p < 0,001), medan idisslingstid och tuggtid för NDF från grovfoder minskade med 18,9 respektive 26,3 min / kg (p < 0,001). Sammanfattningsvis ökade extrudering ensilageintag, äthastighet och mjölkproduktion men minskade tuggningsaktiviteten
Feed Rations in Dairy Production and Their Climate Footprint
No full textDairy production delivers nutrient-dense food but it also constitutes a major source of greenhouse gas (GHG) emissions. Feed formulation plays a central role in shaping both productivity and the climate footprint of dairy systems. This thesis investigated how feed ration formulation can reduce GHG emissions from Swedish high-producing dairy production whilst maintaining productivity. This was addressed across multiple system levels, from the individual animal to the regional food system. Two feeding trials with dairy cows and heifers evaluated animal performance and enteric methane (CH4) emissions. Study I compared two pelleted concentrate mixes, formulated with low-carbon-footprint (CF) by-products (BYP) and/or domestically sourced (DOM) ingredients, to a commercially available mix (COM). Both reduced feed-related GHG emissions without compromising feed intake, milk yield, or enteric CH4 emissions from high-producing (43.3 ± 5.4 kg ECM/d) Swedish Holstein cows. Study II tested a ration designed for forage scarcity, where whole-crop wheat silage was partially incorporated (50:50 DM basis) in grass-clover silage-based diets fed to Holstein and Nordic Red heifers. This substitution did not negatively affect feed intake, growth rate, or enteric CH4 emissions. Results from these trials were integrated into a farm-level life cycle assessment (Study III). At the farm level, when compared to COM, BYP decreased total farm-level GHG emissions (-6%) and land use (-3.8%), whilst DOM achieved smaller reductions in farm-level GHG emissions (-2.1% to -2.6%) but increased land use (up to +6.8%). At the regional level (Study IV), scenario modelling of dairy production in northern Sweden illustrated trade-offs among climate footprint, land use, feed self-sufficiency, and milk output. This thesis demonstrates that feed rations based on low-CF ingredients can reduce GHG emissions from high-yielding Swedish dairy production without compromising animal performance. However, the environmental outcomes depend on ingredient choice and system boundaries, highlighting the need to evaluate feeding strategies at multiple system levels to inform sustainable dairy development
The dairy production system in the north of Sweden under possible future food scenarios
Get PDFContext: The dairy production system fills an important role by providing nutrient-dense foods in Swedish diets, however, future efforts to improve its sustainability necessitate structural changes. Objective: We present an innovative study which assesses the effects of these future changes in the dairy system in northern Sweden, the Norrland region, which has a subarctic climate. Methods: Four scenarios were developed: 1) Food as Industry: Food is a commodity, and its production is an industry that can be invested in to benefit society. 2) Food as Technology: New technologies, such as nutrient density trackers and microbiome mapping, are used for personalized dietary plans. Additionally, novel foods from microbial cultures are produced. 3) Food as Culture: More locally produced food and diverse food products are consumed. 4) Food Forgotten: Land previously used for food and feed is converted to bioenergy production, climate mitigation, and adaptation infrastructure. These scenarios were compared to the baseline i.e. present dairy system for dairy production capacity, carbon flow and carbon footprint. Results and conclusions: Food as industry resulted in increased dairy production capacity with decreased carbon footprint but increased carbon imports. Food as technology provided decreased dairy production capacity and increased carbon footprint but with decreased carbon imports. Food as culture, maintained dairy production capacity with a decreased carbon footprint and carbon imports. Food forgotten resulted in decreased dairy production capacity and increased carbon imports but with decreased carbon footprint. Food as culture benefits all- specifically dairy production capacity, carbon footprint and carbon imports. However, further research is required to explore implications on soil organic carbon stocks over time in Norrland. Significance: Our study sheds light on the potential impacts of future dairy production in a subarctic climate and aims to help in decision making
Considering greenhouse gas emissions from feed production in diet formulation for dairy cows as a means of reducing the carbon footprint
Get PDFDairy production often faces conflicting goals, such as reducing greenhouse gas emissions, increasing food production and achieving self-sufficiency without transgressing planetary boundaries. This study examined ways to decrease emissions intensity per kg of milk from high-producing cows by selecting feed ingredients with a low carbon footprint while also considering local alternatives. Diets comprising of grass-legume mixture silage and three concentrate mixtures (standard commercial, based on byproducts, and domestic crops grown on-farm) were randomly allotted to three groups of highproducing Swedish Holstein cows (N = 48). Over 7 weeks, no differences were observed (mean +/- SEM) in feed DM intake (commercial: 24.3, by-products: 24.7, domestic: 24.2 kg/day, +/- 0.51 kg/day), energycorrected milk (ECM) yield (commercial: 38.3, by-products: 38.5, domestic: 37.8, +/- 0.98 kg/day) or enteric methane production (commercial: 387, by-products: 378, domestic: 402 g/day, +/- 17.3 g/day) among the diets. However, an evaluation of the primary carbon footprint of feed production (excluding transportation emissions) showed that the by-products and domestic diets gave lower emissions than the commercial diet, 9.4, 10.2, and 11.9 Feed CO2 equivalents (CO2-eq) kg/day, respectively (SEM: +/- 0.38 Feed CO2-eq kg/day). The emission intensity, expressed as feed emissions per kilogram of ECM yield, showed that the by-product-based and domestic diets generated lower carbon footprints, with emissions of 254 and 284 g Feed CO2-eq/kg ECM, respectively, in comparison to 320 g Feed CO2-eq/kg ECM observed for the commercial diet (SEM: +/- 10.7 g Feed CO2-eq/kg ECM). Considering greenhouse gas emissions from feed production in diet formulation resulted in a lower overall feed carbon footprint and lower emission intensity per ECM. These findings can assist in formulating dairy rations for high-yielding dairy cows that balance conflicting goals while maintaining productivity. (c) 2025 The Author(s). Published by Elsevier B.V. on behalf of The animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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