Grazing influences on pasture plants : literature study

Bachelor i agronomi. Blæstad 2013Beiting i vekstsesongen er viktig for drøvtyggerproduksjonen i Norge, og det har en del sammenheng med topografiske grunner. Grunner som også vanskeliggjør fornying av plantedekket. Derfor er vi tjent med å ha beiter som er produktive over år, uten at ugress tar over. Det er derfor interessant å se nærmere på samspillet mellom beitedyr og beiteplanter. Gjennom dette litteraturstudiet er det samlet kunnskap om hvordan beitingen påvirker beiteplantene, og hvordan produksjonen kan opprettholdes over tid. Det er basert på norsk og utenlandsk litteratur. Studiet begynner med å ta for seg hvordan aktiviteten til beitedyrene virker. Beitedyrene påvirker plantene med avbeiting, tråkk og gjødsel. Avbeiting har som regel mest betydning. Det er forskjell på beitemåten til de forskjellige husdyrene, med blant annet ulik selektivitet. Hvilke beitetype det er snakk om har også betydning. Oppgaven begrenser seg til innmarksbeite. Beiteplantene på innmark domineres av flerårige gress og belgvekster. Det kan være både naturlige og sådde arter. Beiteplantene trenger energi og den får de gjennom fotosyntesen. Den prosessen foregår i blad og grønne plantedeler. Bladarealet har derfor stor betydning for produksjonen til beiteplantene. Energien lagres som karbohydratreserver i plantene, spesielt i nedre del. Karbohydratreservene dekker energibehovet til gjenvekst etter beiting, når det er lite blad. Reservene er også viktig om vinteren og vekststarten om våren. Reservene må få tid til å bygges opp igjen mellom beitingene av en plante, for at den ikke skal svekkes. Energien brukes til vekst hos beiteplantene, som skjer ut fra forskjellige meristemer. Et av de er det apikale meristemet, eller vekstpunktet. Når det beites vekk må nye skudd brytes fra knopper ved skuddets basis. Vekstpunktet er nært bakken, og beskyttet mot beiting, så lenge planten er i vegetativt fase. Da er også gjenveksten etter beiting raskest. Senere, i reproduktiv fase, er planten større og vekstpunktet hevet. Det må også nevnes at rotutviklingen har nær sammenheng med hvor belastet de grønne plantedelene er. Den har igjen betydning for styrken til beiteplanten. Veksten i beitet varierer gjennom sesongen. Den er størst på forsommeren og synker utover sesongen. Om høsten lagres reserver, samt at det dannes knopper. Tilstrekkelig energi er kritisk for beiteplantene i denne tiden. Følgelig kan for sterk beiting på dette tidspunktet svekke plantene. Beitingen medfører en gjentatt syklus med vekst og beiting. For å oppnå optimal produksjon må vekstpotensialet utnyttes samtidig som plantene ikke må tømmes for energi. Et sted mellom den vegetative fasen, med rask gjenvekst og strekningsfasen, med størst produksjon, burde man finne optimalområdet. Beitingen kan også medføre ulike konsekvenser for forskjellige planter. På grunn av at beitedyrene kan være selektive og på grunn av forskjeller mellom beiteplantene, kan beiting medføre en endring i botanisk sammensetning i beitet. Plantene kan være mer eller mindre motstandsdyktig mot beiting, ved at de tåler eller unngå beiting. I praktisk beitebruk kan man forsøke å motvirke de ugunstige påvirkningene beitingen kan medføre på plantebestandet. I tillegg til dyrenes behov må man også ta hensyn til plantenes behov. Det kan skilles mellom kontinuerlig beiting og skiftebeiting. Skiftebeiting gir mer styringsmuligheter. Samspillet mellom beitedyr og beiteplanter er komplekst. Med kunnskap om spesifikke egenskaper ved både plantertartene i beitet og dyrene som beiter der, kan det være mulig å tilpasse beitingen slik at produksjonen på arealene opprettholdes over tid.Grazing during the growing season is important for ruminant production in Norway, and it is much related to topographical reasons. Reasons which also make the renewal of plant cover difficult. Because of that, we benefit from having pastures that are productive over years, without weeds taking over. It is therefore interesting to examine the interaction between grazing animals and pasture plants. Through this literature study knowledge is collected on how grazing affects pasture plants, and how production can be maintained over time. It is based on Norwegian and international literature. The study begins with an insight at how the activity of grazing animals works. Grazing animals influence the plants by defoliation, trampling and manure. Defoliation usually is most important. There are differences in grazing behavior between different animals, which includes selectivity of plants. Type of pasture land is also important. This study is excluding rangeland. Pasture plants is dominated by grasses and leguminous plants, both natural and cultivated species. Pasture plants need energy, which is supplied by photosynthesis, a process taken place in leaves and other green parts of plants. Leaf area is therefore very important for the production of pasture plants. Energy is stored as carbohydrate reserves in plants, especially in the lower plant part. Carbohydrate reserves cover the energy needs of regrowth after grazing, when little leaf area left. The reserves are also important to survive the winter and for growth during spring. Rebuilding of the carbohydrate reserves has to be given time between the grazing of a plant, which otherwise becomes weakened. Pasture plants need energy and the energy is supplied by the photosynthesis. That process takes place in the leafs and green parts of plants. Leaf area is therefore very important for the production of pasture plants. Energy is stored as carbohydrate reserves in plants, especially in the lower part. Carbohydrate reserves cover the energy needs of regrowth after grazing, when there is little leaf area. Reserves are also important in winter and spring growth. Reserves must be given time to rebuild before between grazing of a plant, so it does not become weakened. Growth of pasture plants occurs at different meristems. One of them is the apex meristem, the growth point. When the growth point is removed, new tillers will sprout from buds at tiller basis. When the plant is in its vegetative phase the growth point is close to the ground, thus protected from grazing. At this time the regrowth after grazing is fastest. The grazing involves repeating cycles of growth and grazing. To achieve optimum production, we want the growth potential to be utilized without letting plants be depleted of energy. Somewhere between the vegetative phase of rapid regrowth and elevating phase, with the greatest production, one should find the optimum. The grazing involves a repeating cycle of growth and grazing. To achieve optimum production, we want the growth potential to be utilized without let plants be emptied of energy. Somewhere between the vegetative phase of rapid regrowth and elevating phase, with the greatest production, one should find the optimum area. The grazing may also lead to different consequences for different plants. Because the grazing animals may be selective, and because of differences exist between pasture plant species, grazing can result in a change in the flora composition of pastures. The plants may be more or less resistant to grazing by either tolerance or avoiding of grazing. In practical use of grazing one has possibilities to counteract the adverse impacts grazing can have on plant populations. It is necessary to take into account not only the needs of the grazing animals, but also the plant needs. We can distinguish between continuous grazing and rotational grazing. Rotational grazing provides more management options. The interaction between grazing animals and pasture plants is complex. With knowledge of the specific characteristics of the plant species in the pasture and the animals that graze it, it may be possible to adapt the grazing so that production is maintained over time

Betre metodikk for estimering av lystgassutslepp frå dyrka mark brukt i nasjonal rapportering

Rapporten gjev ei oversikt over metodikk for rapportering av lystgassutslepp brukt i nokre utvalde land, og ei vurdering av om dette er aktuelt for Norge. Rapporten omhandlar vidare korleis Norge kan gå frå Tier 1 standard utsleppsfaktor til nasjonal utsleppsfaktor Tier 1 for direkte lystgassutslepp frå tilført nitrogen i mineralgjødsel og husdyrgjødsel på jordbruksareal. Rapporten vurderer også om det er mogleg for Norge å gå frå Tier 1 til Tier 2 i utsleppsrekneskapen. Eit meir detaljert samandrag finn ein på side 5 i rapporten.publishedVersio

Tiltak for å redusere ammoniakkutslepp frå jordbruket

Rapporten estimerer potensialet for ammoniakkreduksjon av tiltak knytt til husdyrgjødsel og mineralgjødsel, og dei samfunns- og privatøkonomiske kostnadane ved innføring av tiltaka. Reduksjon av lystgass- og metanutslepp som følgje av ammoniakkreduserande tiltak er også estimert. Ulike tiltak knytt til spreiing av husdyrgjødsel på eng har størst potensial for ammoniakkreduksjon

Prenatal exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may influence birth weight among infants in a Swedish cohort with background exposure: a cross-sectional study

BACKGROUND: Prenatal exposure to persistent organic pollutants, e.g. polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) has been suggested to negatively affect birth weight although epidemiological evidence is still inconclusive. We investigated if prenatal exposure to PCBs and PBDEs is related to birth weight in a Swedish population with background exposure. METHODS: Breast milk was sampled during the third week after delivery from first-time mothers in Uppsala county, Sweden 1996–2010 (POPUP cohort) (N = 413). Samples were analysed for di-ortho PCBs (CB-138, 153, 180) and tetra- to hexa- brominated PBDEs (BDE-47, 99, 100, 153). Simple and multiple linear regression models were used to investigate associations between lipid-adjusted, ln-transformed PCB and PBDE concentrations, and birth weight. Covariates included in the multivariate regression model were PCB and PBDE exposure, maternal age, pre-pregnancy BMI, weight gain during pregnancy, education, smoking, gender of the infant and gestational length. The effect of including fish consumption was also investigated. RESULTS: In the multivariate model, prenatal exposure to di-ortho PCBs was significantly associated with increased birth weight (β = 137; p = 0.02). The result did not change when gestational length was added to the model. An inverse association between PBDE(4) (sum of BDE-47, -99, -100 and −153) and birth weight was observed in the multivariate model including gestational length (β = −106; p = 0.04). Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders of the association between di-ortho PCBs and birth weight. The associations were not alleviated after adjustment for fish consumption, a major source of PCB and PBDE exposure. The observed associations were stronger for boys than for girls. CONCLUSIONS: Our results indicate that prenatal exposure to di-ortho PCBs and PBDE(4) may influence birth weight in different directions, i.e. PCB exposure was associated with higher birth weight and PBDE exposure with lower birth weight. Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders that may hide positive association between di-ortho PCB exposure and birth weight if they are not included in the statistical model. We speculate that even small PCB- and PBDE-induced shifts in the distribution of birth weight may influence future public health in populations with background exposure

Mobile group I introns at nuclear rDNA position L2066 harbor sense and antisense homing endonuclease genes intervened by spliceosomal introns

publishedVersio

Strategic Administration for Online Courses in Communication and Writing Programs

The strategic administration of online courses in communication and writing programs depends on a balance of standardization and flexibility to meet the needs of diverse stakeholders. Based on experiences managing online courses in three large communication and writing programs, the authors of this study argue that exercising collaborative leadership and using iterative development principles to create pre-designed courses can support a sustainable approach to creating user-centered learning experiences for both students and instructors. In addition to providing a research-based rationale and sharing situated examples, this study provides specific recommendations to help programs promote collaborative leadership and integrate elements of the PARS framework—personal, accessible, responsive, and strategic—into the iterative development of pre-designed courses.This book chapter is published as Anders, A., Aune, J. Fulton, K., Kretsinger-Harries, A., Walton, A., and White, C. (2023). Strategic Administration for Online Courses in Large Communication and Writing Programs. In J. Borman & C. McArdle. (Eds), PARS for Writing Programs. Chapter 13;186-205.https://wac.colostate.edu/books/practice/pars3/ . Posted with permission. Copyright © 2023 Jessie Borgman, Casey McArdle, and the authors of individual parts of this book. This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 International License. 344 pages, with notes, illustrations, and bibliographies. This book will be available in print from University Press of Colorado as well as from any online or brick-and-mortar bookstore. Available in digital formats for no charge on this page at the WAC Clearinghouse. You may view this book. You may print personal copies of this book. You may link to this page. You may not reproduce this book on another website

Interleukin-6 in Allogeneic Stem Cell Transplantation: Its Possible Importance for Immunoregulation and As a Therapeutic Target

Allogeneic stem cell transplantation is associated with a high risk of treatment-related mortality mainly caused by infections and graft-versus-host disease (GVHD). GVHD is characterized by severe immune dysregulation and impaired regeneration of different tissues, i.e., epithelial barriers and the liver. The balance between pro- and anti-inflammatory cytokine influences the risk of GVHD. Interleukin-6 (IL-6) is a cytokine that previously has been associated with pro-inflammatory effects. However, more recent evidence from various autoimmune diseases (e.g., inflammatory bowel disease, rheumatoid arthritis) has shown that the IL-6 activity is more complex with important effects also on tissue homeostasis, regeneration, and metabolism. This review summarizes the current understanding of how pro-inflammatory IL-6 effects exerted during the peritransplant period shapes T-cell polarization with enhancement of Th17 differentiation and suppression of regulatory T cells, and in addition we also review and discuss the results from trials exploring non-selective IL-6 inhibition in prophylaxis and treatment of GVHD. Emerging evidence suggests that the molecular strategy for targeting of IL-6-initiated intracellular signaling is important for the effect on GVHD. It will therefore be important to further characterize the role of IL-6 in the pathogenesis of GVHD to clarify whether combined IL-6 inhibition of both trans- (i.e., binding of the soluble IL-6/IL-6 receptor complex to cell surface gp130) and cis-signaling (i.e., IL-6 ligation of the IL-6 receptor/gp130 complex) or selective inhibition of trans-signaling should be tried in the prophylaxis and/or treatment of GVHD in allotransplant patients

Gut microbiota composition during hospitalization is associated with 60-day mortality after severe COVID-19

Background - Gut microbiota alterations have been reported in hospitalized COVID-19 patients, with reduced alpha diversity and altered microbiota composition related to respiratory failure. However, data regarding gut microbiota and mortality are scarce. Methods - Rectal swabs for gut microbiota analyses were collected within 48 h after hospital admission (baseline; n = 123) and three-month post-admission (n = 50) in a subset of patients included in the Norwegian SARS-CoV2 cohort study. Samples were analysed by sequencing the 16S rRNA gene. Gut microbiota diversity and composition at baseline were assessed in relation to need for intensive care unit (ICU) admission during hospitalization. The primary objective was to investigate whether the ICU-related gut microbiota was associated with 60-day mortality. Results - Gut microbiota diversity (Shannon index) at baseline was lower in COVID-19 patients requiring ICU admission during hospitalization than in those managed in general wards. A dysbiosis index representing a balance of enriched and reduced taxa in ICU compared with ward patients, including decreased abundance of butyrate-producing microbes and enrichment of a partly oral bacterial flora, was associated with need of ICU admission independent of antibiotic use, dexamethasone use, chronic pulmonary disease, PO2/FiO2 ratio, C-reactive protein, neutrophil counts or creatinine levels (adjusted p  Conclusions - Although our data should be regarded as exploratory due to low number of clinical end points, they suggest that gut microbiota alterations during hospitalization could be related to poor prognosis after severe COVID-19. Larger studies of gut involvement during COVID-19 in relation to long-term clinical outcome are warranted