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Slow callus growth is a barrier to efficient genetic transformation in some gramineous species. A reformulation of Murashige and Skoog (MS) medium, with additional magnesium sulphate, potassium phosphate, copper sulphate, proline ...
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Slow callus growth is a barrier to efficient genetic transformation in some gramineous species. A reformulation of Murashige and Skoog (MS) medium, with additional magnesium sulphate, potassium phosphate, copper sulphate, proline and glutamine, termed WPBS medium, has been developed which improves all aspects of in vitro culture when compared with MS based media. Embryogenic callus could be produced more rapidly from responsive genotypes of sixteen cereal, forage, model and energy grass species, whether using embryos, shoot tips or proliferated meristems as explants. Three species were not transformed due to contamination or unsuitable explant, but thirteen species were transformed using an identical Agrobacterium-mediated transformation, selection and regeneration protocol, including Avena sativa and Oryza sativa. Readily transformable species such as Lolium perenne, Brachypodium distachyon and Festuca arundinacea and recalcitrant species such as Lolium temulentum and Miscanthus sinensis were reliably transformed, while two new species Phalaris arundinacea and viviparous Deschampsia cespitosa were transformed at the first attempt. It is hoped that the use of WPBS media and this general transformation protocol may help to improve the efficiency of grass and cereal transformation.
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As a fuel, biomass differs in its properties from fossil fuels and acquisition thereof for energy purposes is limited; hence, the ongoing search for new bioenergetically useful plants. The article presents the results of physical ...
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As a fuel, biomass differs in its properties from fossil fuels and acquisition thereof for energy purposes is limited; hence, the ongoing search for new bioenergetically useful plants. The article presents the results of physical and chemical analyses of seven species of perennial grasses: tall wheatgrass, tall wheatgrass 'Bamar', brome grass, tall fescue ecotype, reed canary grass, giant miscanthus, and sorghum. The research involved technical and elemental analysis as well as analysis of the ash composition performed in order to determine their potential use for combustion process. The measurement results were compared with those obtained for hard coal and agricultural biomass, which is widely used in the energy industry. The results suggest that perennial grasses can successfully be combusted with similar performance to coal if burned in appropriate combustion installations.
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The heavy reliance of the livestock industry of the European Union (EU) on feed protein imports has initiated a transition to alternative protein sources such as grass proteins. Green biorefineries (which process grass into protei...
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The heavy reliance of the livestock industry of the European Union (EU) on feed protein imports has initiated a transition to alternative protein sources such as grass proteins. Green biorefineries (which process grass into protein and other related bio-products) are gaining interest in the EU as the EU searches for ways to cut its import of feed proteins, to reduce its reliance on fossil fuels, and to combat climate change. However, the vulnerability of green biorefineries to fossil energy constraints has not been studied. We estimated the energy conversion efficiencies (EE) and the energy return on investment (EROI) of bio-products from standalone (SGBR) and integrated grass refinery (IGBR) systems using scenario and energy analysis. The base scenario assumes an SGBR that processes grass into protein, fiber, and brown juice. The three IGBR scenarios assume that grass is processed into protein, fiber, and biomethane (Scenario 1); into protein, fiber, heat, and electricity (Scenario 2); or into protein, fiber, heat, and biomethane (Scenario 3). We found that the EE of the IGBR (83%-85%) largely exceeded that of the SGBR (77%) in all cases. Energy returns on investment were lower for grass than for clover-grass because of the high fertilizer needs of the former. The standard EROIs (EROIstd) for grass protein ranged from 1.6 to 5.4 over the various feedstocks and scenarios evaluated. The EROIstd decreased when the system boundary was expanded to the point of use (EROIpou), or when they were adjusted for quality (EROIqly). Other bioproducts from both SGBR and IGBR also had high EROIstd, and showed similar patterns to that of grass protein (i.e., EROIstd > EROIpou > EROIqly). Although Scenario 1 had a high EE relative to the base scenario, its heavy reliance on auxiliary energy inputs reduced the EROIs of its products. Our analysis showed the strong impacts of brown-juice recycling in the energy performance of green biorefinery. It thus deserves close attention when designing and implementing a green biorefinery in a given region. With favorable economic conditions, green biorefineries could contribute to the reduction of food and energy insecurity in Europe in a sustainable way. (c) 2020 Society of Chemical Industry and John Wiley & Sons, Ltd
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Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH_4 emission has not been fully investigated yet. We investigated the combined...
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Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH_4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (predominantly ryegrass) on CH_4 emission from lactating dairy cows. In a randomized block design, 28 lactating Holstein-Friesian dairy cows received a basal diet of GH and compound feed [85:15; dry matter (DM) basis]. Treatments consisted of GH cut after 3 or 5 weeks of regrowth, after receiving either a low (20 kg of N/ha) or a high (90 kg of N/ha) fertilization rate after initial cut. Feed intake, digestibility, milk production and composition, N and energy balance, and CH_4 emission were measured during a 5-d period in climate respiration chambers after an adaptation to the diet for 12 d. Cows were restricted-fed during measurements and mean DM intake was 15.0 ± 0.16 kg/d. Herbage crude protein content varied between 76 and 161 g/kg of DM, and sugar content between 186 and 303 g/kg of DM. Fat- and protein-corrected milk (FPCM) and feed digestibility increased with increased N fertilization rates and a shorter regrowth interval. Increasing the N fertilization rate increased daily CH_4 emission per cow (+10%) and per unit of DM intake (+9%), tended to increase the fraction of gross energy intake emitted as CH_4 (+7%), and (partly because of the low crude protein content for the low fertilized GH) only numerically reduced CH_4 per unit of FPCM. The longer regrowth interval increased CH_4 emission per unit of FPCM (+14%) compared with the shorter regrowth interval, but did not affect CH_4 emission expressed in any other unit. With increasing N fertilization CH_4 emission decreased per unit of digestible neutral detergent fiber intake (-13%) but not per unit of digestible organic matter intake. There was no interaction of the effect of N fertilization rate and regrowth interval on CH_4 emission, but effects of N fertilization were generally most distinct with GH of 5 wk regrowth. The present results suggest that altering grass quality through an increase of N fertilization and a shorter regrowth interval can reduce CH_4 emission in zero-grazing dairy cows, depending on the unit in which it is expressed. The larger amount of CH_4 produced per day and cow with the more intensively managed GH is compensated by a higher feed digestibility and FPCM yield.
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The objective of this study was to analyse the economic profitability of producing energy-grass fuels on marginal agricultural land in Sweden. Small and irregular-shaped fields, fields with less fertile soils, headlands and border...
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The objective of this study was to analyse the economic profitability of producing energy-grass fuels on marginal agricultural land in Sweden. Small and irregular-shaped fields, fields with less fertile soils, headlands and border strips were included, all located in four different regions representing different cultivation conditions. The grasses studied were reed canary grass (RCG) and ley, which were to be used as a solid fuel and biogas substrate, respectively. The economic profitability of these grasses was compared with the profitability of fallow land and the cultivation of winter wheat and spring barley. The results showed that all the alternatives studied, except winter wheat in southern Sweden, had a negative economic net gain (no subsidies included). Generally, the economic losses were greatest for small and irregular-shaped fields. Fallow had a higher economic competitiveness than RCG and ley for all marginal field categories and locations. RCG used as a solid fuel in boilers generally had a higher competitiveness than ley for biogas. However, when ley was used fresh without storage, its competitiveness improved considerably. Taking the direct payment subsidies and the economic value of reduced nutrient leakage into account, the economic net gain improved considerably. Nevertheless, fallow land still had a somewhat higher net gain than RCG for all field categories. Further cost reductions and higher revenues, including possible agro-environmental economic compensation, are required if RCG and ley are to be able to compete with fallow land.
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Grazed pastures in south-eastern Australia are typically based on temperate (C3) species, such as perennial ryegrass (Lolium perenne). With predictions of warming to occur in this region, there has been growing interest in the per...
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Grazed pastures in south-eastern Australia are typically based on temperate (C3) species, such as perennial ryegrass (Lolium perenne). With predictions of warming to occur in this region, there has been growing interest in the performance of more heat-tolerant and deep-rooted subtropical (C4) pasture grasses, such as kikuyu (Pennisetum clandestinum). This study used an existing pasture model to estimate the production of kikuyu compared with the commonly used perennial ryegrass at seven sites in south-eastern Australia, using an historical baseline climate scenario between 1971 and 2010, and the daily temperature of the baseline scenario adjusted by +1, +2, and +3 degrees C to represent potential warming in the future. The seven sites were chosen to represent the range of climatic zones and soil types in the region. First, the model predictions of monthly kikuyu dry matter (DM) production were validated with measured data at Taree, Camden, and Bega, with results showing good agreement. Second, pasture production (tDM/ha), metabolisable energy (ME, MJ/kgDM) content, and ME yield (GJ/ha) were predicted using the baseline and warmer climate scenarios. The study was based on 56 simulations of the factorial arrangement of seven sites x four temperature scenarios x two pastures. The month and annual ME yield of a kikuyu-subterranean clover (Trifolium subterraneum) pasture and a perennial ryegrass-subterranean clover pasture were compared. This study showed that in summer-dominant rainfall locations, where the average maximum temperature is >23 degrees C, kikuyu was a more productive pasture species than perennial ryegrass. In winter-dominant rainfall locations during the warmer months of December-March, kikuyu can provide a useful source of ME when perennial ryegrass is less productive. With warming of up to 3 degrees C at the winter-dominant rainfall sites, the average ME yield per year of kikuyu was predicted to surpass that of perennial ryegrass, but inter-annual variation in kikuyu production was higher. The nutritive value, seasonal distribution of growth, total annual production, and its variability are all important considerations for producers when selecting pasture species.
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Levels of lignin and hydroxycinnamic acid wall components in three genera of forage grasses (Lolium, Festuca and Dactylis) have been accurately predicted by Fourier-transform infrared spectroscopy using partial least squares model...
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Levels of lignin and hydroxycinnamic acid wall components in three genera of forage grasses (Lolium, Festuca and Dactylis) have been accurately predicted by Fourier-transform infrared spectroscopy using partial least squares models correlated to analytical measurements. Different models were derived that predicted the concentrations of acid detergent lignin, total hydroxycinnamic acids, total ferulate monomers plus dimers, p-coumarate and ferulate dimers in independent spectral test data from methanol extracted samples of perennial forage grass with accuracies of 92.8%, 86.5%, 86.1%, 59.7% and 84.7% respectively, and analysis of model projection scores showed that the models relied generally on spectral features that are known absorptions of these compounds. Acid detergent lignin was predicted in samples of two species of energy grass, (Phalaris arundinacea and Pancium virgatum) with an accuracy of 84.5%.
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Levels of lignin and hydroxycinnamic acid wall components in three genera of forage grasses (Lolium, Festuca and Dactylis) have been accurately predicted by Fourier-transform infrared spectroscopy using partial least squares model...
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Levels of lignin and hydroxycinnamic acid wall components in three genera of forage grasses (Lolium, Festuca and Dactylis) have been accurately predicted by Fourier-transform infrared spectroscopy using partial least squares models correlated to analytical measurements. Different models were derived that predicted the concentrations of acid detergent lignin, total hydroxycinnamic acids, total ferulate monomers plus dimers, p-coumarate and ferulate dimers in independent spectral test data from methanol extracted samples of perennial forage grass with accuracies of 92.8%, 86.5%, 86.1%, 59.7% and 84.7% respectively, and analysis of model projection scores showed that the models relied generally on spectral features that are known absorptions of these compounds. Acid detergent lignin was predicted in samples of two species of energy grass, (Phalaris arundinacea and Pancium virgatum) with an accuracy of 84.5%.
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Improved nutrient utilization efficiency is strongly related to enhanced economic performance and reduced environmental footprint of dairy farms. Pasture-based systems are widely used for dairy production in certain areas of the w...
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Improved nutrient utilization efficiency is strongly related to enhanced economic performance and reduced environmental footprint of dairy farms. Pasture-based systems are widely used for dairy production in certain areas of the world, but prediction equations of fresh grass nutritive value (nutrient digestibility and energy concentrations) are limited. Equations to predict digestible energy (DE) and metabolizable energy (ME) used for grazing cattle have been either developed with cattle fed conserved forage and concentrate diets or sheep fed previously frozen grass, and the majority of them require measurements less commonly available to producers, such as nutrient digestibility. The aim of the present study was therefore to develop prediction equations more suitable to grazing cattle for nutrient digestibility and energy concentrations, which are routinely available at farm level by using grass nutrient contents as predictors. A study with 33 nonpregnant, nonlactating cows fed solely fresh-cut grass at maintenance energy level for 50 wk was carried out over 3 consecutive grazing seasons. Freshly harvested grass of 3 cuts (primary growth and first and second re-growth), 9 fertilizer input levels, and contrasting stage of maturity (3 to 9 wk after harvest) was used, thus ensuring a wide representation of nutritional quality. As a result, a large variation existed in digestibility of dry matter (0.642-0.900) and digestible organic matter in dry matter (0.636-0.851) and in concentrations of DE (11.8-16.7 MJ/kg of dry matter) and ME (9.0-14.1 MJ/kg of dry matter). Nutrient digestibilities and DE and ME concentrations were negatively related to grass neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents but positively related to nitrogen (N), gross energy, and ether extract (EE) contents. For each predicted variable (nutrient digestibilities or energy concentrations), different combinations of predictors (grass chemical composition) were found to be significant and increase the explained variation. For example, relatively higher R~2 values were found for prediction of N digestibility using N and EE as predictors; gross-energy digestibility using EE, NDF, ADF, and ash; NDF, ADF, and organic matter digestibilities using N, water-soluble carbohydrates, EE, and NDF; digestible organic matter in dry matter using water-soluble carbohydrates, EE, NDF, and ADF; DE concentration using gross energy, EE, NDF, ADF, and ash; and ME concentration using N, EE, ADF, and ash. Equations presented may allow a relatively quick and easy prediction of grass quality and, hence, better grazing utilization on commercial and research farms, where nutrient composition falls within the range assessed in the current study.
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The objective of this study was to evaluate the effect of cutting frequency in Cayman grass ( Urochloa HYBRID) on biomass yield, moisture, ash, ethereal extract, neutral detergent fiber (FDN), acid detergent fiber (FDA), acid dete...
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The objective of this study was to evaluate the effect of cutting frequency in Cayman grass ( Urochloa HYBRID) on biomass yield, moisture, ash, ethereal extract, neutral detergent fiber (FDN), acid detergent fiber (FDA), acid detergent lignin (LDA), crude protein (PC), calorific value, and theoretical bioethanol yield. Four cutting frequencies were established as treatments: 30, 60, 90, and 120 d, arranged in a completely randomized block design with three replications. Data were analyzed with GLM (SAS), and means were compared with the Tukey test ( p ≤ 0.05). The highest biomass production (11.9 Mg ha -1 year -1 ), calorific value (15.1 MJ kg -1 ), and LDA (5.7 %) were obtained at the 120 d cutting frequency. The concentration of FDN (61.8 %), FDA (43.6 %), cellulose (38.1 %), and theoretical bioethanol production (218.4 L Mg -1 MS) were statistically different at the cutting frequency of 90 d. The values of hemicellulose (18. 7 %) and ethereal extract (1.8 %) were statistically different at the 60 d-cutting frequency; while PC (9.7 %) and ash (11.8 %) showed significant differences at the 30-d cutting frequency. Based on the biomass yield and calorific value of Cayman grass, it can be considered as a potential plant material for cellulosic ethanol production.
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