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1
McCaskill, MR, and JG McIvor. "Herbage and animal production from native pastures and pastures oversown with Stylosanthes hamata. 2. Modelling studies." Australian Journal of Experimental Agriculture 33, no. 5 (1993): 571. http://dx.doi.org/10.1071/ea9930571.
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Data from a long-term grazing experiment were used to develop relationships suitable for modelling between-year variation in pasture and animal production. The experiment was conducted near Townsville in North Queensland and consisted of a factorial combination of 2 stocking rates (0.6, 1.2 steers/ha) x 2 pasture types (native pasture, native pasture plus Stylosanthes hamata cv. Verano) x 2 superphosphate rates (nil, 300 kg/ha.year). Cattle were weighed monthly, and the herbage presentation yield and stylo content estimated annually. Relationships between annual liveweight gain (LWG) and a range of climate-derived parameters including the number of 'green days' were calculated from a water balance and pasture growth model. When a different intercept was allowed for each pasture and stocking rate combination, there was a strong relationship between annual LWG and the number of 'green days' (R2 = 0.78). In a more general relationship, LWG was related to green days, stylo content, and utilisation rate (R2 = 0.58). No relationships was found that would enable reliable prediction of between-year variation in the pasture attributes of stylo content and the water use efficiency of herbage growth. The times of the year when daily rates of LWG changed could be predicted satisfactorily, but rate of gain within each phase varied considerably from year to year. Differences in LWG between stocking rates occurred when there would have been restricted amounts of new green feed, or of stylo in the late wet season.
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Rashid, Muhammad Imtiaz, Ron G. M. de Goede, Lijbert Brussaard, Jaap Bloem, and Egbert A. Lantinga. "Production-ecological modelling explains the difference between potential soil N mineralisation and actual herbage N uptake." Applied Soil Ecology 84 (December 2014): 83–92. http://dx.doi.org/10.1016/j.apsoil.2014.07.002.
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Fleming, A. E., D. Dalley, R. H. Bryant, G. R. Edwards, and P. Gregorini. "Modelling feeding strategies to improve milk production, rumen function and discomfort of the early lactation dairy cow supplemented with fodder beet." Journal of Agricultural Science 158, no. 4 (May 2020): 313–25. http://dx.doi.org/10.1017/s0021859620000593.
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AbstractFeeding fodder beet (FB) to dairy cows in early lactation has recently been adopted by New Zealand dairy producers despite limited definition of feeding and grazing management practices that may prevent acute and sub-acute ruminal acidosis (SARA). This modelling study aimed to characterize changes of rumen pH, milk production and total discomfort from FB and define practical feeding strategies of a mixed herbage and FB diet. The deterministic, dynamic and mechanistic model MINDY was used to compare a factorial arrangement of FB allowance (FBA), herbage allowance (HA) and time of allocation. The FBA were 0, 2, 4 or 7 kg dry matter (DM)/cow/day (0FB, 2FB, 4FB and 7FB, respectively) and HA were 18, 24 or 48 kg DM/cow/day above ground. All combinations were offered either in the morning or afternoon or split across two equal meals. Milk production from 2FB diets was similar to 0FB but declined by 4 and 16% when FB increased to 4 and 7 kg DM, respectively. MINDY predicted that 7FB would result in SARA and that rumen conditions were sub-optimal even at moderate FBA (pH < 5.6 for 160 and 90 min/day, 7FB and 4FB respectively). Pareto front analysis identified the best compromise between high milk production and low total discomfort was achieved by splitting the 2FB diet into two equal meals fed each day with 48 kg DM herbage. However, due to low milk response and high risk of acidosis, it is concluded that FB is a poor supplement for lactating dairy cows.
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Seligman, N. G., and H. Van Keulen. "Herbage production of a Mediterranean grassland in relation to soil depth, rainfall and nitrogen nutrition: A simulation study." Ecological Modelling 47, no. 3-4 (September 1989): 303–11. http://dx.doi.org/10.1016/0304-3800(89)90008-2.
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Badgery, W. B., D. Mitchell, G. D. Millar, K. Broadfoot, D. L. Michalk, P. Cranney, and W. Brown. "Designing a grazing-system experiment for variable native pastures and flexible lamb-production systems." Animal Production Science 57, no. 9 (2017): 1785. http://dx.doi.org/10.1071/an15856.
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Grazing-system experiments address complex interactions among animals, pastures, soils, climate and management. As part of the national EverGraze program, a grazing-system experiment was designed to determine how the intensity of grazing management, from continuous grazing (P01) to flexible 4- and 20-paddock rotational systems (P04 and P20), influences the profitability and sustainability of a Merino ewe, terminal sire, lamb production system grazed on heterogeneous native pastures. When implementing such an experiment, it is important to understand and characterise landscape variability, and include this in the design of the experiment. A second challenge for grazing-system research is to operate experimental systems with sufficient flexibility to adequately represent commercial production systems and maintain even utilisation across treatments. The present paper addresses the following two issues: (1) the process used to characterise the potential productivity of variable native pastures and the results of this characterisation; and (2) the development of flexible systems that adequately represent commercial production within an experiment. This was undertaken with input from a project-steering committee called the EverGraze Regional Group, comprising producers, extension staff and private consultants. Prior to the commencement, the site was mapped into three production zones, namely, high (HPZ), medium (MPZ) and low (LPZ), by visually estimating green herbage mass in late spring and marking boundaries between zones with a GPS. The production zones represented differences in soil properties (gravel, pH and available P) and pasture composition, and were used to balance potential production among plots within the same replication. Grazing-system options were evaluated using the sustainable grazing systems pasture model to help choose an appropriate starting stocking rate. The initial stocking rate chosen for the spring-lambing systems was 5.4 ewes/ha. The modelling predicted large variations in feed availability and quality over summer among years; flexible management criteria were therefore developed, including variable sale time for lambs, to utilise the greater feed supply in better seasons. Minimum-pasture benchmarks (>0.8 t DM/ha standing herbage mass and >80% ground cover) and variable green herbage-mass targets were designed to sustain high levels of livestock production and prevent pasture degradation. Criteria for adjusting ewe numbers were developed, but were constrained to pre-joining (March), scanning (July) and post-weaning (December), being consistent with commercial practices. The experiment incorporated flexible management rules as these were considered integral to the successful management of commercial grazing systems.
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McDonald, C. K., and R. M. Jones. "Relationships between age and biomass of individual plants and seed production in two grazed tropical legumes. 1. Derivation of relationships." Australian Journal of Agricultural Research 53, no. 2 (2002): 91. http://dx.doi.org/10.1071/ar00174.
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The distributions of individual plant age and biomass of Chamaecrista rotundifolia cv. Wynn and a mix of Stylosanthes scabra cvv. Seca and Fitzroy in grazed grass–legume pastures were examined to determine their effect on seed production. The effects of enhanced soil water conditions and severe defoliation on seed production were assessed in ungrazed plots. These experiments were part of a larger study to develop a demographic model of perennial forage legumes. The distribution of individual plant age and biomass was highly skewed towards a large number of young/small plants, with fewer old/large plants. Lack of seed set when stem length was less than approximately 200 mm, and in most small plants (<2 g), resulted in older/larger plants contributing far more to seed production and, to a lesser extent, legume biomass, than they did to legume plant numbers. C. rotundifolia seed production was linearly related to individual plant biomass but was highly varaiable and was greatly reduced in swards containing >3000 kg/ha of grass. Using log-transformed data, plant biomass accounted for 74% of the variation in seed production (SP), but together with grass biomass accounted for 91% of the variation [ln(SP) = 6.01 + 0.91*ln(BIOMASS) – 0.28*ln(GRASS BIOMASS), P < 0.001]. Total legume biomass accounted for only 44% of the variation in seed production. S. scabra herbage allowance (kg legume/head) had a major impact on seed production. Total legume biomass and individual plant biomass alone accounted for less than 40% of the variation in seed production. Using herbage allowance (HA) as well as individual plant biomass improved the prediction of seed production (SP) to account for 74% of the variation [ln(SP) = 0.11 + 1.14*ln(BIOMASS) + 0.24*ln(HA), P < 0.001]. Enhanced soil water conditions increased the biomass of individual plants of both species and increased the seed production per gram of plant in S. scabra but not in C. rotundifolia. Severe defoliation in early summer or autumn can greatly reduce or even eliminate seed production by some plants by removal of flowers, reducing individual plant biomass, or allowing insufficient time for plants to reach minimum stem lengths. The different factors affecting seed production in the 2 species highlight the complexity of legume seed set in grazed pasture systems, and some implications for grazing management and modelling are discussed.
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Dodd, M. B., D. E. Dalley, D. Elliott, and C. M. Wims. "Establishment year productivity, botanical composition and nutritive value of grass/lucerne/plantain dairy pasture mixtures." Journal of New Zealand Grasslands 79 (January 1, 2017): 229–35. http://dx.doi.org/10.33584/jnzg.2017.79.534.
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In the context of dairy grazing systems, pasture mixtures including tall fescue, lucerne and plantain have been identified by animal modelling as having potential to both improve milk production and reduce urinary nitrogen excretion. A grazed paddock-scale trial was established in the Waikato in September 2015 to test this in two short-term grazing trials including these species. This paper presents the pasture production, botanical composition and nutritive value data generated from four pasture mixtures sown in spring 2015 and sampled until autumn 2017 (18 months). The pasture mixtures represented a comparison between perennial ryegrass and tall fescue, with and without the herb narrow-leaved plantain. The inclusion of plantain in grass-lucerne mixtures had a positive effect on firstyear herbage dry matter (DM) production, by ~2.6 t DM/ha/year in ryegrass-based pastures and ~1.6 t DM/ ha/year in tall fescue-based pastures. Where plantain was included, the proportion of grass was reduced by more than half from autumn 2016 through to summer 2016-2017, while the proportion of lucerne was reduced to a lesser degree. The proportion of plantain was 35-70% through most of the first year, declining to
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Snow, V. O., P. N. Smale, and M. B. Dodd. "Process-based modelling to understand the impact of ryegrass diversity on production and leaching from grazed grass-clover dairy pastures." Crop and Pasture Science 64, no. 10 (2013): 1020. http://dx.doi.org/10.1071/cp13263.
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Ecological studies often suggest that natural grasslands with high species diversity will grow more biomass and leach less nitrogen (N). If this diversity effect also applies to fertilised and irrigated pastures with controlled removal of herbage, it might be exploited to design pastures that can assist the dairy industry to maintain production while reducing N leaching losses. The purpose of this study was to test whether pasture mixtures with a high functional diversity in ryegrass traits will confer on the system higher water- and N-use efficiency. The hypothesis was tested using a process-based model in which pasture mixtures were created with varying levels of diversity in ryegrass traits likely to affect pasture growth. Those traits were: the winter- or summer-dominance of growth, the ability of the plant to intercept radiation at low pasture mass, and rooting depth. Pasture production, leaching and water- and N-use efficiency were simulated for management typical of a dairy pasture. We found that the performance of the diverse ryegrass–clover mixtures was more strongly associated with the performance of the individual components than with the diversity across the components. Diverse pasture mixtures may confer other benefits, e.g. pest or disease resistance and pasture persistence. The testing here was within a selection of ryegrasses, and the greater possible diversity across species may produce different effects. However, these results suggest that highly performing pastures under fertilised and irrigated grazed conditions are best constructed by selecting components that perform well individually than by deliberately introducing diversity between components.
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Pembleton, K. G., R. P. Rawnsley, J. L. Jacobs, F. J. Mickan, G. N. O'Brien, B. R. Cullen, and T. Ramilan. "Evaluating the accuracy of the Agricultural Production Systems Simulator (APSIM) simulating growth, development, and herbage nutritive characteristics of forage crops grown in the south-eastern dairy regions of Australia." Crop and Pasture Science 64, no. 2 (2013): 147. http://dx.doi.org/10.1071/cp12372.
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Pasture-based dairy farms are a complex system involving interactions between soils, pastures, forage crops, and livestock as well as the economic and social aspects of the business. Consequently, biophysical and farm systems models are becoming important tools to study pasture-based dairy systems. However, there is currently a paucity of modelling tools available for the simulation of one key component of the system—forage crops. This study evaluated the accuracy of the Agricultural Production Systems Simulator (APSIM) in simulating dry matter (DM) yield, phenology, and herbage nutritive characteristics of forage crops grown in the dairy regions of south-eastern Australia. Simulation results were compared with data for forage wheat (Triticum aestivum L.), oats (Avena sativa L.), forage rape (Brassica napus L.), forage sorghum (Sorghum bicolor (L.) Moench), and maize (Zea mays L.) collated from previous field research and demonstration activities undertaken across the dairy regions of south-eastern Australia. This study showed that APSIM adequately predicted the DM yield of forage crops, as evidenced by the range of values for the coefficient of determination (0.58–0.95), correlation coefficient (0.76–0.94), and bias correction factor (0.97–1.00). Crop phenology for maize, forage wheat, and oats was predicted with similar accuracy to forage crop DM yield, whereas the phenology of forage rape and forage sorghum was poorly predicted (R2 values 0.38 and 0.80, correlation coefficient 0.62 and –0.90, and bias correction factors 0.67 and 0.28, respectively). Herbage nutritive characteristics for all crop species were poorly predicted. While the selection of a model to explore an aspect of agricultural production will depend on the specific problem being addressed, the performance of APSIM in simulating forage crop DM yield and, in many cases, crop phenology, coupled with its ease of use, open access, and science-based mechanistic methods of simulating agricultural and crop processes, makes it an ideal model for exploring the influence of management and environment on forage crops grown on dairy farms in south-eastern Australia. Potential future model developments and improvements are discussed in the context of the results of this validation analysis.
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Pequeno, Diego N. L., Carlos G. S. Pedreira, and Kenneth J. Boote. "Simulating forage production of Marandu palisade grass (Brachiaria brizantha) with the CROPGRO-Perennial Forage model." Crop and Pasture Science 65, no. 12 (2014): 1335. http://dx.doi.org/10.1071/cp14058.
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Forage-based livestock systems are complex, and interactions among animals, plants and the environment exist at several levels of complexity, which can be evaluated using computer modelling. Despite the importance of grasslands for livestock production in Brazil, tools to assist producers to make decisions in forage–livestock systems are scarce. The objective of this research was to use the CROPGRO-Perennial Forage model to simulate the irrigated and rainfed growth of Marandu palisade grass (Brachiaria brizantha (A. Rich.) Stapf. cv. Marandu), the most widely grown forage in Brazil, by using parameters previously calibrated for the tall-growing cv. Xaraes of the same species, under non-limiting water conditions. The model was calibrated for the irrigated experiment and then tested against independent data of the rainfed experiment. Data used to calibrate the model included forage production, plant-part composition, leaf photosynthesis, leaf area index, specific leaf area, light interception and plant nitrogen (N) concentration from a field experiment conducted during 2011–13 in Piracicaba, SP, Brazil. Agronomic and morpho-physiological differences between the two grasses, such as maximum leaf photosynthesis, N concentration and temperature effect on growth rate, were considered in the calibration. Under rainfed conditions, the simulations using the Penman–Monteith FAO 56 method gave a more realistic water stress response than the Priestley and Taylor method. After model parameterisation, the mean simulated herbage yield was 4582 and 5249 kg ha–1 for 28 days and 42 days irrigated, and 4158 and 4735 kg ha–1 for 28 days and 42 days rainfed, respectively. The root-mean-square error ranged from 464 to 526 kg ha–1 and the D-statistic from 0.907 to 0.962. The simulated/observed ratios ranged from 0.977 to 1.001. These results suggest that the CROPGRO-Perennial Forage model can be used to simulate growth of Marandu palisade grass adequately under irrigated and rainfed conditions.
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Broadfoot, K. M., W. B. Badgery, and G. D. Millar. "Post-experimental modelling of grazing systems to improve profit and environmental outcomes using AusFarm." Animal Production Science 57, no. 9 (2017): 1849. http://dx.doi.org/10.1071/an16129.
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Assessments of grazing systems are often constrained by the decisions regarding the management of the grazing systems, including stocking rate, and also the seasonal conditions that occur during the assessment period. These constraints have led to sometimes conflicting results about comparisons of grazing management systems. This paper examines 1-, 4- and 20-paddock (1P, 4P and 20P) grazing management systems to determine how the intensity of grazing management on native pastures influences the financial performance of sheep production systems. The performance of the grazing systems, as part of the Orange EverGraze research experiment, was initially examined using the biophysical data over the 4 years of the experiment and then a more detailed analysis over a longer timeframe was undertaken using the AusFarm simulation modelling software. Flexible management strategies to optimise ewe numbers, sale time of lambs, and adjust ewe numbers based on season, were also assessed to determine which management systems are the most profitable and sustainable. There was higher profit for the 20P grazing system than the 1P system during the experiment. However, when stocking rates were held constant at optimum levels and systems were simulated over 40 years, there was no difference between grazing systems. Modelling strategies used to vary stocking rates showed that flexible management options are better based on optimising ewe numbers and the sale time of lambs rather than changing ewe numbers between years. The sustainability of modelled systems was also assessed using frequency of events where the average herbage mass (0.8 t DM/ha) or ground cover (80%) in autumn dropped below levels that are associated with degradation. Degradation events occurred more so with increasing ewe number than lamb sale time. Overall, the most sustainable systems, when considering profitability and environmental issues, had a stocking rate of 4.2 ewes per ha, with lambs sold in February (2 or 18). Higher stocking rates (5.3 ewes/ha) would need to be run for more intensive grazing management to have higher profitability.
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Fleming, Anita, Konagh Garrett, Kelly Froehlich, Matthew Beck, Racheal H. Bryant, Grant Edwards, and Pablo Gregorini. "Supplementation of Spring Pasture with Harvested Fodder Beet Bulb Alters Rumen Fermentation and Increases Risk of Subacute Ruminal Acidosis during Early Lactation." Animals 10, no. 8 (July 30, 2020): 1307. http://dx.doi.org/10.3390/ani10081307.
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In a cross-over design, eight rumen cannulated dairy cows were used to explore the industry-recommended method for dietary transition to fodder beet (FB: Beta vulgaris L.) on changes to rumen fermentation and pH, milk production, dry matter intake (DMI) and the risk of subacute ruminal acidosis (SARA) during early lactation. Cows were split into two groups and individually allocated a ryegrass (Lolium Perenne L.) and white clover (Trifolium repens L.) diet (HO) or the same herbage supplemented with 6 kg DM/cow of harvested fodder beet bulbs (FBH). Dietary adaptation occurred over 20 days consisting of: stage 1: gradual transition to target FB intake (days 1–12, +0.5 kg DM of FB/d); stage 2: acclimatization (days 13–17) and stage 3: post-adaption sampling (days 18–20). Response variables were analyzed as a factorial arrangement of diet and stage of adaption using a combination of ANOVA and generalized linear mixed modelling. Dietary proportion of FB represented 22, (stage 1), 32 (stage 2) and 38% (stage 3) of daily DMI. One cow during each period developed SARA from FB and the duration of low pH increased with FBH compared to the HO treatment (p < 0.01). Rumen concentrations of lactic and butyric acid increased with FBH but concentrations of acetate, propionate and total volatile fatty acids (VFA) declined by 9.3% at day 20, compared to the HO treatment (p < 0.01). Treatments did not affect milk production but total DMI with supplemented cows increased during the final stage of adaptation and feed conversion efficiency (FCE kg milk/kg DM) declined with the FBH treatment. The occurrence of SARA in 25% of animals fed FB suggest it is a high-risk supplement to animal health and further evaluation of industry-recommended methods for feeding FB at the individual- and herd-scale are needed.
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Unkovich, Murray. "Nitrogen fixation in Australian dairy systems: review and prospect." Crop and Pasture Science 63, no. 9 (2012): 787. http://dx.doi.org/10.1071/cp12180.
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Quantitative measurement of N2 fixation has rarely been conducted in Australian dairy pastures. The available data indicate that annual N2 fixation rates in Australian dairy pastures are generally low, due to low pasture legume content. With typical legume contents of grazed pastures less than 30% of total pasture biomass production, annual N2 fixation in herbage is usually much less than 50 kg ha–1 year–1. Other factors which are likely to be able to contribute to increased N2 fixation input (rhizobia, mineral N management, soil acidity, soil water contents) will have little impact until such time as legume contents are increased. In contrast, for some hay systems, such as those using lucerne, N2 fixation input is shown to be high (200–300 kg ha–1 year–1). While pasture clover contents remain low there is little value in study or measurement of N2 fixation, nor in complex modelling, as N2 fixation will be of little quantitative importance. However, where legume contents, and thus potential N2 fixation are increased, there is scope for investigation into potential increases in N input from this source, which is invariably linked to fertiliser application, the management of grazing and the N returns in urine and dung. These are the major influences on sward N dynamics and legume N2 fixation. The inoculant rhizobia used for white clover in Australia (TA1) is likely to be suboptimal. Isolated in Tasmania in 1953 it has been shown to be inferior in N2 fixation compared with other strains on several occasions. Root pests and diseases are likely to be prevalent and impact directly on clover root growth and perhaps nodulation. Modelling is often used to describe the probable influence of management and/or climate on the operation of agricultural systems. Reliable modelling of N2 fixation requires capacity to integrate the effects of grazing and pasture composition on soil mineral N dynamics, the influence of this mineral N on nodulation and on suppression of N2 fixation, and environmental and management influences on soil rhizobial populations. Currently no models have demonstrated this capacity. At present, a suitably calibrated regression model is probably a good option for modelling N2 fixation in Australian dairy pastures. Environmental benefits ensuing from increasing N2 fixation and substituting this for fertiliser N are likely to be greater off-farm (reduced GHG emissions at site of fertiliser manufacture) than on, if current fertiliser management is optimal. Nevertheless substituting fixed N for fertiliser N would have modest environmental and feed efficiency benefits.
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Scott, J. M., K. Behrendt, A. Colvin, F. Scott, L. M. Shakhane, C. Guppy, J. Hoad, et al. "Integrated overview of results from a farmlet experiment which compared the effects of pasture inputs and grazing management on profitability and sustainability." Animal Production Science 53, no. 8 (2013): 841. http://dx.doi.org/10.1071/an12284.
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The Cicerone Project conducted a grazed farmlet experiment on the Northern Tablelands of New South Wales, Australia, from July 2000 to December 2006, to address questions raised by local graziers concerning how they might improve the profitability and sustainability of their grazing enterprises. This unreplicated experiment examined three management systems at a whole-farmlet scale. The control farmlet (farmlet B) represented typical management for the region, with flexible rotational grazing and moderate inputs. A second farmlet (farmlet A) also used flexible rotational grazing but had a higher level of pasture renovation and soil fertility, while the third farmlet (farmlet C) had the same moderate inputs as farmlet B but employed intensive rotational grazing. The present paper provides an integrated overview of the results collated from component papers and discusses the inferences that can be drawn from what was a complex, agroecosystem experiment. The measurements recorded both early and late in the experiment were tabulated for each of the farmlets and compared with each other as relative proportions, allowing visual presentation on a common, indexed scale. Because of equivalent starting conditions, there was little difference between farmlets early in the experimental period (2000–01) across a wide array of measured parameters, including herbage mass, potential pasture growth rate, liveweight, wool production per head, stocking rate, gross margin and equity. Although the experiment experienced drier-than-average conditions, marked differences emerged among farmlets over time, due to the effects of treatments. During the latter half of the experimental period (2003–06), farmlet A showed numerous positive and a few negative consequences of the higher rate of pasture renovation and increased soil fertility compared with the other two farmlets. While intensive rotational grazing resulted in superior control of gastrointestinal nematodes and slightly finer wool, this system had few effects on pastures and no positive effects on sheep liveweights, wool production or stocking rate. Whereas farmlet A showed higher gross margins, it had a negative and lower short-term cash position than did farmlets B and C, due largely to the artificially high rate of pasture renovation undertaken on this farmlet during the experiment. Although farmlet B had the highest cash position at the end of the experiment, this came at a cost of the declining quality of its pastures. Modelling of the farmlet systems allowed the results to be considered over the longer timeframes needed to assess sustainability. Thus, returns on investment were compared over realistic amortisation periods and produced outcomes based on long-term climatic expectations which were compared with those that arose under the drier-than-average conditions experienced during the experimental period. The main factors responsible for lifting the productivity of farmlet A were the sowing of temperate species and increased soil fertility, which enhanced the amount of legume and increased pasture quality and potential pasture growth. The factor that affected farmlet C most was the low proportion of the farmlet grazed at any one time, with high stock density imposed during grazing, which decreased feed intake quality. The paper concludes that more profitable and sustainable outcomes are most likely to arise from grazing enterprises that are proactively managed towards optimal outcomes by maintaining sufficient desirable perennial grasses with adequate legume content, enhancing soil fertility and employing flexible rotational grazing.
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Chotikamas, Sumitta, Kraipat Cheenkachorn, Boochita Wongpanit, Prapakorn Tantayotai, and Malinee Sriariyanun. "Chemical Profiling Analysis and Identification the Bioactivities of Herbal Compress Extracts." MATEC Web of Conferences 187 (2018): 01001. http://dx.doi.org/10.1051/matecconf/201818701001.
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The traditional Thai herbal compress is composed of six different types of herbs including Ginger (Zingiber cassumunar), Turmeric (Curcuma longa Linn.), Soap Pod (Acacia concinna), Kaffir lime (Citrus hystrix), Lemongrass (Cymbopogon citratus), and Tamarind (Tamarindus indica Linn.). Herbal compress is used in treatment of Thai traditional massage to relieve the body pain and muscle strains. The objective of this work is to perform chemical profiling and extraction modelling of herbal compress obtained from solvent extraction method. The kinetic models, The second order and Fick‘s second law, representing the extraction behaviors of bioactive compounds were constructed to fit with experimental data of solvent extraction. Under tested condition, the extraction equilibrium was reached after 360 min and the second-order model gives the best fit for the experimental data with high coefficients of correlation (R2 = 0.9927). Additionally, chemical profiling analysis showed that the amounts and variations of bioactive components in drying-pretreated herbal compress were more abundant than that of untreated sample. This finding could be applied further for preparation and production of traditional Thai herbal compress in the industrial scale.
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Uhlenbrock, Lukas, Maximilian Sixt, Martin Tegtmeier, Hartwig Schulz, Hansjörg Hagels, Reinhard Ditz, and Jochen Strube. "Natural Products Extraction of the Future—Sustainable Manufacturing Solutions for Societal Needs." Processes 6, no. 10 (October 1, 2018): 177. http://dx.doi.org/10.3390/pr6100177.
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The production of plant-based extracts is significantly influenced by traditional techniques and the natural variability of feedstock. For that reason, the discussion of innovative approaches to improve the manufacturing of established products and the development of new products within the regulatory framework is essential to adapt to shifting quality standards. This perspective of members of the DECHEMA/ProcessNet working group on plant-based extracts outlines extraction business models and the regulatory framework regarding the extraction of traditional herbal medicines as complex extracts. Consequently, modern approaches to innovative process design methods like QbD (Quality by Design) and quality control in the form of PAT (Process Analytical Technology) are necessary. Further, the benefit of standardized laboratory equipment combined with physico-chemical predictive process modelling and innovative modular, flexible batch or continuous manufacturing technologies which are fully automated by advanced process control methods are described. A significant reduction of the cost of goods, i.e., by a factor of 4–10, and decreased investments of about 1–5 mil. € show the potential for new products which are in line with market requirements.
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Li, F. Y., R. Vibart, R. A. Dynes, I. Vogeler, and M. Brown. "Effects of weather variability on sheep and beef farming in northern Southland, New Zealand: A modelling analysis." Proceedings of the New Zealand Grassland Association, January 1, 2012, 77–83. http://dx.doi.org/10.33584/jnzg.2012.74.2887.
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Inter-annual weather variation has profound effects on pasture production and pastoral farm performance. However, the relationship between the variation in herbage and animal production and farm economic and environmental (nitrate leaching and greenhouse gas emission) outcomes are not clearly quantified, especially with varying farm management strategies applied under variable weather scenarios. We used a pasture model (APSIM-AgPasture), corroborated by measured pasture growth data, to generate pasture growth curves for a typical sheep and beef farm in northern Southland for the past 39 years, and grouped them into five weather scenarios. We fed these curves into a farm system model (Farmax) to examine the changes in farm performance with various management adaptations. We found that farm economic and environmental outcomes did not respond proportionally to pasture production; compared with the variation range in herbage production, the variation range in animal production was smaller, but the variation range in farm profitability was larger. Environmental efficiency (nitrate leaching and greenhouse gas emissions per unit of animal products) was high in wet years. Our results highlight the importance of considering the nonproportional changes among pasture production, animal production, profitability, and environmental outcomes of pastoral farming when selecting farm management strategies and tactics to adapt to weather variations, and indicate the necessity of incorporating these non-linear relationships in the development of farm management decision support tools. Key words: Climate variability, pasture herbage production, animal production, production efficiency, environmental efficiency, management adaptation
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Easton, H. S., J. M. Amyes, N. E. Cameron, R. B. Green, G. A. Kerr, M. G. Norriss, and A. V. Stewart. "Pasture plant breeding in New Zealand: where to from here?" Proceedings of the New Zealand Grassland Association, January 1, 2002, 173–79. http://dx.doi.org/10.33584/jnzg.2002.64.2455.
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Ecologically sustainable pastures remain the base of New Zealand's competitive advantage in livestock production, but while modest but steady productivity gains from pasture plant breeding have been documented, these appear to be difficult to convert to livestock production, and pasture production is perceived as up against a ceiling. This paper discusses the contribution of pasture plant breeding, focusing on the ryegrasses, and to a lesser extent on white clover. Heritable variation is evident in the basic components of herbage growth and herbage quality. However, changes to individual traits are not reflected in improved integrated field performance. More precise information is required on how factors interact. New breeding technologies will allow integrated improvement of interacting factors. Evaluation trials and modelling should be managed to provide feed-back identifying the specific requirements of future high-performing systems. Keywords: New Zealand, plant breeding, ryegrass, white clover
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Barker, D. J., D. A. Clark, E. R. Thom, J. N. Couchman, R. N. Burton, and N. Dymock. "Pasture species and drought impacts on milk yield 2. Predicted farm milk yield at four sites." Proceedings of the New Zealand Grassland Association, January 1, 1998, 45–50. http://dx.doi.org/10.33584/jnzg.1998.60.2305.
Full textAbstract:
A desirable option for increasing milk yield per farm is to increase milk production in summer without compromising peak-season production or the duration of lactation. The dairy industry has a goal to achieve a 4% per month post-peak decline of milk production. The effect of five pasture types and two summer water regimes on predicted farm milk yield, in Northland, Waikato, Manawatu and Canterbury was measured over 1 year. Two pasture treatments, resident pasture and Grasslands Nui ryegrass, were common to all sites. A third pasture treatment varied between sites: triple mix (Grasslands Advance tall fescue, Grasslands Kara cocksfoot, and Grasslands Maru phalaris) at the Manawatu site; the same triple mix but with Grasslands Raki paspalum at the Northland site; and low-endophyte ryegrass and Grasslands Kahu timothy (LER) at the Canterbury site; all sown treatments included red and white clover. All five pasture types were included at the Waikato site. On average for all pasture types, water deficit reduced summer herbage accumulation (HA) to 79, 68, 43 and 18% of irrigated controls, and annual HA to 88, 80, 73 and 63% of irrigated controls in Northland, Waikato, Manawatu and Canterbury, respectively. Since farm milk yield predicted by UDDER was highly correlated with annual HA (R2 = 83%), the effects of pasture type and water deficit on milk yield were similar to effects on HA. Seasonal and annual HA differed among the five pasture types at each of the four sites. The most important factor affecting predicted farm milk yield was annual HA, with relatively little effect from the seasonal pattern of pasture growth. Differences in shapes of the predicted milk supply curves for various treatments occurred, particularly when drought forced early drying-off. The best predicted summer milk yield was for the Canterbury irrigated LER pasture treatment, a 6.8% per month postpeak decline of milk production. Keywords: farm milk yield, farm system modelling, forage supply, pasture species, water deficit
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Ashaari, Nur Suhanawati, Mohd Hairul Ab. Rahim, Suriana Sabri, Kok Song Lai, Adelene Ai-Lian Song, Raha Abdul Rahim, and Janna Ong Abdullah. "Kinetic studies and homology modeling of a dual-substrate linalool/nerolidol synthase from Plectranthus amboinicus." Scientific Reports 11, no. 1 (August 24, 2021). http://dx.doi.org/10.1038/s41598-021-96524-z.
Full textAbstract:
AbstractLinalool and nerolidol are terpene alcohols that occur naturally in many aromatic plants and are commonly used in food and cosmetic industries as flavors and fragrances. In plants, linalool and nerolidol are biosynthesized as a result of respective linalool synthase and nerolidol synthase, or a single linalool/nerolidol synthase. In our previous work, we have isolated a linalool/nerolidol synthase (designated as PamTps1) from a local herbal plant, Plectranthus amboinicus, and successfully demonstrated the production of linalool and nerolidol in an Escherichia coli system. In this work, the biochemical properties of PamTps1 were analyzed, and its 3D homology model with the docking positions of its substrates, geranyl pyrophosphate (C10) and farnesyl pyrophosphate (C15) in the active site were constructed. PamTps1 exhibited the highest enzymatic activity at an optimal pH and temperature of 6.5 and 30 °C, respectively, and in the presence of 20 mM magnesium as a cofactor. The Michaelis–Menten constant (Km) and catalytic efficiency (kcat/Km) values of 16.72 ± 1.32 µM and 9.57 × 10–3 µM−1 s−1, respectively, showed that PamTps1 had a higher binding affinity and specificity for GPP instead of FPP as expected for a monoterpene synthase. The PamTps1 exhibits feature of a class I terpene synthase fold that made up of α-helices architecture with N-terminal domain and catalytic C-terminal domain. Nine aromatic residues (W268, Y272, Y299, F371, Y378, Y379, F447, Y517 and Y523) outlined the hydrophobic walls of the active site cavity, whilst residues from the RRx8W motif, RxR motif, H-α1 and J-K loops formed the active site lid that shielded the highly reactive carbocationic intermediates from the solvents. The dual substrates use by PamTps1 was hypothesized to be possible due to the architecture and residues lining the catalytic site that can accommodate larger substrate (FPP) as demonstrated by the protein modelling and docking analysis. This model serves as a first glimpse into the structural insights of the PamTps1 catalytic active site as a multi-substrate linalool/nerolidol synthase.