Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 3091 - 3120 of 42668

Full-Text Articles in Entire DC Network

Origin, Regulation, And Function Of Bone Marrow Adipose Tissue And Implications For Bone Health, Xiao Zhang Aug 2024

Origin, Regulation, And Function Of Bone Marrow Adipose Tissue And Implications For Bone Health, Xiao Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Bone marrow adipose tissue (BMAT) is a unique fat depot located within the skeletal system that takes up a large portion of the total bone marrow volume and contains tremendous amounts of energy that can be potentially utilized to fuel the body. However, largely attributed to its strong resistance to lipolytic stimuli and its persistent accumulation in various physiological and pathological conditions, the exact function of BMAT within the bone and how it is regulated throughout the body remains largely unclear. This dissertation sought to better understand the unique role of BMAT within the bone marrow niche by first reviewing …


Relative Productivity And Persistense Of White Clover Cultivars Under Cutting Or Continuous Stocking By Sheep, D A. Davies, M Fothergill Aug 2024

Relative Productivity And Persistense Of White Clover Cultivars Under Cutting Or Continuous Stocking By Sheep, D A. Davies, M Fothergill

IGC Proceedings (1977-2023)

Perennial ryegrass-white clover (Lolium perenne-Trlfollium repens) swards of 3 clover cultivars were studied at a lowland (30 m) and upland (340 m) site in mid Wales over 3 years (1989-91). Lamb production from small-leaved Aberystwyth S 184 at 1021 kg/ha was 25% and 1191, more than from small-leaved Ac3351 and medium-leaved Grasslands Huia respectively. The relative lamb output from Huia was poorer at the upland location. Clover production, survival and morphology under a number of cutting heights and frequencies were different from those in the continuously stocked pastures. Cutting every 10 days at 2-3 cm resulted in poor clover and …


Response To Defoliation Of Tall Fescue, H Tavakoli, J Hodgson, P D. Kemp Aug 2024

Response To Defoliation Of Tall Fescue, H Tavakoli, J Hodgson, P D. Kemp

IGC Proceedings (1977-2023)

An experiment studying the behaviour of toll fescue (Fesutca anrundinacea Schreb,) was conducted under steady stale grazing on a sward dominated by this plant. The swards were grazed lo maintain a surface height of 30-40 mm (H), 50-60 mm (M) and 90-100 mm (L). These treatments were applied on swards with and without white clover (Trifolium repens L.) from November 1990 to April 1991. Results showed that leaf growth decreased as the severity of grazing increased. Tiller number was less under H grazing than under M or L grazing, but tiller size remained constant over time in this …


Adaptation Of Sainfoin Cultivars And Lucerne To Water Stress, S R. Mir Hosseini, P D. Kemp, D J. Barker, J Hodgson Aug 2024

Adaptation Of Sainfoin Cultivars And Lucerne To Water Stress, S R. Mir Hosseini, P D. Kemp, D J. Barker, J Hodgson

IGC Proceedings (1977-2023)

Sainfoin ( Onobrychis viciifolia Scop.) is of particular interest as a pasture crop because it is a productive legume in dry areas but does not induce bloat in ruminant animals. In this study 3·sainfoin cultivars (Fakir, Melrose and 035) and l lucerne (Medicago saliva L.) cultivar Grasslands Oranga were compared during a drying phase when water was withheld once; flowering began. A randomised complete block design with 4 replicates' was used. Transpiration rate (Tr) declined as volumetric soil water content (VSWC) was reduced. Stomata! resistance (Rs) increased and relative ivater content (RWC) decreased when VSWC decreased. Critical VSWC for …


Prediction Of Plant Mortality Under Grazing- A Conceptual Approach, J J. Mott, G K. Mckeon, K A. Day Aug 2024

Prediction Of Plant Mortality Under Grazing- A Conceptual Approach, J J. Mott, G K. Mckeon, K A. Day

IGC Proceedings (1977-2023)

Based on the concept of biological thresholds, there is growing acceptance 0£ the importance o£ episodic events in the determination of rangeland condition trend. The variable rainfall occurring within Australian rangelands means that overstocking during droughts is a major cause of these Australian rangeland vegetation complexes exceeding these thresholds. Recently plant production models and simplistic estimates of the relationship between animal utilisation and plant mortality became available. Accurate estimates will be developed only with the incorporation of a sound mechanistic understanding of the relationship between utilisation of forage and plant mortality for different conditions of species and soils. Detailed studies …


Modular Approach To Soft Mobile Robots, Dimuthu Kodippili Arachchige Aug 2024

Modular Approach To Soft Mobile Robots, Dimuthu Kodippili Arachchige

College of Computing and Digital Media Dissertations

Soft robot locomotion is a highly promising but under-researched subfield within the field of soft robotics. The compliant limbs and bodies of soft robots offer numerous benefits, including the ability to regulate impacts, tolerate falls, and navigate through tight spaces. These robots have the potential to be used for various applications, such as search and rescue, inspection, surveillance, and more. The state-of-the-art still faces many challenges, including limited degrees of freedom, a lack of diversity in gait trajectories, insufficient limb dexterity, limited payload capabilities, lack of control methods, etc. To address these challenges, this research introduces a modular approach to …


Investigating Cloth Sculpting For Simulation Control In Virtual Reality, Matthew S. Bishop Aug 2024

Investigating Cloth Sculpting For Simulation Control In Virtual Reality, Matthew S. Bishop

Theses and Dissertations

Artists require control and predictability over physically based simulations to create their required animation. This control can lead to reduced iteration time to get the desired simulation results. Controlling cloth simulations can require manual effort to create goal keyframes for control algorithms to match. Current techniques and research utilize a keyboard and mouse to create these goal keyframes. Other research has looked at using a virtual reality (VR) head-mounted display with controllers to improve the experience of completing similar animation tasks. However, we are not aware of any research that attempts to use VR as a tool to assist artists …


Charlotte: A Modern Tool For Cave Surveying, Luca Tringali Mr., Giacomo Canciani Dr., Alexander Debenjak, Tecla Tripari Aug 2024

Charlotte: A Modern Tool For Cave Surveying, Luca Tringali Mr., Giacomo Canciani Dr., Alexander Debenjak, Tecla Tripari

International Journal of Speleology

The future of cave surveying is a full 3D scan, as automatic as possible, capturing all morphologically relevant details. However, the vast majority of cavers are still using tools designed more than 15 years ago. The advancements in tools for architects, CAD designers, programmers of VR and robotics could be helpful also for the caving community. That’s why Charlotte, a cheap DIY 2.5D scanner designed for cave surveying, was developed and built. To demonstrate its capabilities, a new survey of Grotta Regina del Carso cave (cad. nr. 2328/4760VG), the biggest cave in the Gorizia Karst, has been realized and published. …


Maximizing Legged Accelerations: A Matter Of Force, Time, And Gravity, Lance Brooks Aug 2024

Maximizing Legged Accelerations: A Matter Of Force, Time, And Gravity, Lance Brooks

Applied Physiology and Wellness Theses and Dissertations

Sprint running accelerations require runners to apply surface forces that: support body weight by pushing downward, accelerate the body horizontally by pushing backward, and align the direction of the push with the body’s mass center to maintain balance and posture, which imposes an upper limit on the average forward acceleration force equal to the average gravitational force (1.0 G) acting on the runner. This expectation arises from the mechanical constraints imposed by the need to generate sufficient vertical force to support body weight against gravity while simultaneously producing horizontal force to accelerate forward and aligning the push through the center …


Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Applications For Metabolomics, Darcy Cochran, Robert Powers Aug 2024

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Applications For Metabolomics, Darcy Cochran, Robert Powers

Robert Powers Publications

Metabolomics is an interdisciplinary field that aims to study all metabolites < 1500 Da that are ubiquitously found within all organisms. Metabolomics is experiencing exponential growth and commonly relies on high-resolution mass spectrometry (HRMS). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is a form of HRMS that is particularly well suited for metabolomics research due to its exceptionally high resolution (105–106) and sensitivity with a mass accuracy in parts per billion (ppb). In this regard, FT-ICR-MS can provide valuable insights into the metabolomics analysis of complex biological systems due to unique capabilities such as the easy separation of isobaric and isomeric species, isotopic fine structure analysis, spatial resolution of metabolites in cells and tissues, and a high confidence (error) in metabolite identification. Alternatively, the large and complex data sets, long acquisition times, high cost, and limited access mainly through national mass spectrometry facilities may impede the …


Madelung Mechanics And Superoscillations, Mordecai Waegell Aug 2024

Madelung Mechanics And Superoscillations, Mordecai Waegell

Mathematics, Physics, and Computer Science Faculty Articles and Research

In single-particle Madelung mechanics, the single-particle quantum state Ψ(⃗x, t) = R(⃗x, t)eiS(⃗x,t)/h is interpreted as comprising an entire conserved fluid of classical point particles, with local density R(⃗x, t)2 and local momentum ⃗∇S(⃗x, t) (where R and S are real). The Schrödinger equation gives rise to the continuity equation for the fluid, and the Hamilton–Jacobi equation for particles of the fluid, which includes an additional density-dependent quantum potential energy term Q(⃗x, t) = − ¯h2 2m ⃗∇R(⃗x,t) R(⃗x,t) , which is all that makes the fluid behavior nonclassical. In particular, the quantum potential can become negative and create a …


Searching For New Germplasm For The Year 2000 And Beyond, Rainer Schultze-Kraft, Warren M. Williams, John M. Keoghan Aug 2024

Searching For New Germplasm For The Year 2000 And Beyond, Rainer Schultze-Kraft, Warren M. Williams, John M. Keoghan

IGC Proceedings (1977-2023)

The likely germplasm needs for the next decades are discussed with major emphasis on tropical pastures, although many of the considerations apply also to temperate grasslands. The largest, and internationally most relevant, tropical-germplasm collections are held by CSIRO, CIAT and ILCA. Gerznplasm of <600 grass and <1500 legume species is available (with 6000-7000 and 26000-28000 accessions, respectively), representing 100-120 grass and 150-200 legume genera. Temperate germplasm collections are more numerous and hold larger numbers of accessions; they are, however, even more narrowly focused on very few genera (mainly four legume and eight grass genera). The numbers of species represented in the germplasm collections are only a fraction of considerably higher figures suggested in the literature as wild species with forage potential. Further collections to increase this fraction and to safeguard germplasm from genetic erosion and loss of biodiversity are warranted. International co-operation is suggested. Future germplasm needs are seen, in the tropics, mainly for low-input production systems on marginal, degraded lands and for agropastoral systems, and, in the temperate zone, for sustainable grasslands systems. Because of their dual­purpose characteristics legumes are expected to play a key role. It is suggested that the present collections might not contain a sufficiently broad base of germplasm with the required characteristics for the aforementioned production systems. Collection gaps can be identified only through thorough analyses of important genera and regions, based on a solid body of information that still needs to be assembled. A series of research topics is suggested to assist in future collection strategies, germplasm management and evaluation, and to create the basis for future breeding projects. However, expensive and long-term breeding programmes with tropical and many temperate forages are not encouraged for the near future unless the respective species and its natural variability are well enough known. The same applies to genetic manipulation via biotechnology. Implications arising from molecular biology are that new techniques are now available to improve understanding of genetic diversity and taxonomic relationships, and that the potential genetic resource now spans animals, micro-organisms and plants other than the target species. This wider genepool is also endangered and its conservation will rely on in situ preservation of the diverse ecosystems of which it is composed. The need of international support, co-operation and co-ordination regarding germplasm collection, related research and communication is emphasised. The creation of an JBPGR-sponsored, permanent, international working group on forages is suggested.


Plant List Of Accepted Nomenclature, Taxonomy And Symbols, J S. Peterson Aug 2024

Plant List Of Accepted Nomenclature, Taxonomy And Symbols, J S. Peterson

IGC Proceedings (1977-2023)

The Plant List of Accepted Nomenclature, Taxonomy & Symbols (PLANTS) is a dynamic database providing scientific and vernacular names, distributional, growth form, origin, symbols and bibliographic standardised botanical data to US federal agencies. PLANTS encompasses the vascular plant, moss, lichen and liverwort flora of North America, north of the Mexico border, including US states and territories.


A Study On The Promising Ecotypes Of Secale Montaanum Guss., Bahram Peymani-Fard Aug 2024

A Study On The Promising Ecotypes Of Secale Montaanum Guss., Bahram Peymani-Fard

IGC Proceedings (1977-2023)

Secale montamum (mountain rye) has been identified as a well-adapted species for rehabilitation of the substeppic rangelands of Iran. Further investigation on the quality and quantity values of different ecotypes of this species was required. The main objective of this study was to determine phenological stages, herbage yield and protein percentage of the promising native ecotypes of Secale montanum. This research was conducted on 7 ecotypes in which early growth started in late April and heading occurred in late May. Comparison of the 4-year total herbage yield indicated significant differences among the ecotypes, Secale momtanum (10091), which was the previously …


Forage Quality Determinants Of Mott Elephantgrass And Pennisetum Hybrids, L E. Sollenberger, J E. Moore, J A. Flores-C, C J. Chaparro, B Macoon Aug 2024

Forage Quality Determinants Of Mott Elephantgrass And Pennisetum Hybrids, L E. Sollenberger, J E. Moore, J A. Flores-C, C J. Chaparro, B Macoon

IGC Proceedings (1977-2023)

Daily gains of cattle grazing Mott elephantgrass (MB; Pennisteum purpureIum Schum.) arc approximately twice those obtained on other warm-season perennial grasses grown in Florida, USA, but plant characteristics responsible for the high forage quality of MB have not been identified. Three experiments were conducted during 1987- 1991 to determine factors that explain the high forage quality of MB and to assess the quality potential of P. purpureum x P. glaucum (L.) [R.Br.J x clephantgrass hybrids. Higher organic matter (OM) digestibility and intake of MB than Pensacola bahiagrass (PB; Paspalum nonatum Flugge) were associated with a lesser percentage of sclercnchyma (1.6 …


Characterisation Of Us Collection Of Clover And Special Purpose Legume Germplasm, R R. Smith, K H. Quesenberry Aug 2024

Characterisation Of Us Collection Of Clover And Special Purpose Legume Germplasm, R R. Smith, K H. Quesenberry

IGC Proceedings (1977-2023)

Systematic collection of forage legume germplasm by the USA from the centers of origin was initiated in the 1890s. Since then over 11 000 accessions of clover and special-purpose legume species have been introduced into the US. These accessions are catalogued and maintained by the National Plant Germplasm System with working collections located at 4 locations in the US. Appropriate passport and evaluation data are available in the US Germplasm Resources Information Network (GRIN). The Clover and Special Purpose Legume Crop Advisory Commitlee is responsible for providing advice to the National Plant Germplasm System on the collection, mnintenance, evaluation and …


Potential Of European Perennial Ryegrass Germplasm In Southern New Zealand, K H. Widdup, D L. Ryan Aug 2024

Potential Of European Perennial Ryegrass Germplasm In Southern New Zealand, K H. Widdup, D L. Ryan

IGC Proceedings (1977-2023)

86 cullivars of perennial ryegrass from The Netherlands, Germany, Denmark, France and Britain together with 9 New Zealand (NZ) cultivars were evaluated for agronomic potential in the cool, temperate southern region of NZ. Spaced plants of each cultivar were established in 1989 and screened for seasonal growth, moiphological features, head emergence, foliar diseases and endophyte presence. Principal Component Analysis (PCA) was used to order the relative performance of the cultivars taking all characters into consideration. A group containing 5 elite tetraploid and 10 diploid European cultivars showed potential for improving the summer feed quality of ryegrass. These cultivars contained densely …


Germplasm Collecting By Iger: The Future, N R. Sackville Hamilton, K H. Chorlton, I D. Thomas, M D. Hayward Aug 2024

Germplasm Collecting By Iger: The Future, N R. Sackville Hamilton, K H. Chorlton, I D. Thomas, M D. Hayward

IGC Proceedings (1977-2023)

This paper will present novel approaches being implemented or planned lo improve future collections for forage germplasm, and to deal with changing priorities, with particular reference to Lolium perenne. With a large number of accessions already in the gene bank and providing a wide range of genes for possible utilisation, future collections must be targeted ever more precisely, The principle object is to acquire novel genes not already present in the gene bank, to maximise the proportion of genes in the gene pool of L. perenne that is held in the gene bank. A subsidiary object, to support not …


Germplasm Collection, Evaluation And Selection Of Naturalized Medicago Polymorpha In The Mediterranean Zone Of Chile, C Ovalle, J Avendano, A Del Pozo, D Crespo Aug 2024

Germplasm Collection, Evaluation And Selection Of Naturalized Medicago Polymorpha In The Mediterranean Zone Of Chile, C Ovalle, J Avendano, A Del Pozo, D Crespo

IGC Proceedings (1977-2023)

An introduction and evaluation programme is described that thus far includes 53 accessions of the naturalised annual medic Medicago polymorplia L. collected along a 1000 km N-S gradient in central. Chile and subsequently grown together in a common environment· selection trial together with 5 accessions received from International Center for Agricultural Research in the Dry Areas (!CARDA). Major selection criteria include: precocious phenology, spineless pods and hardseededness, and tolerance to acid soils. Onset of flowering was 82-127 day_s, later flowering being closely correlated with higher latitudes. Soil pH was 5.3-7 .5 in collection sites, and phosphorus levels were > 10 ppm …


The Genera Vicia And Lathyrus In Rio Grande Do Sul (Southern Brazil): Cytogenetic And Isozymic Evaluation As Support For Plant Breeding, M T. Schifino-Wittmann, L H. Cardoso De Freitas, A H. Lau Aug 2024

The Genera Vicia And Lathyrus In Rio Grande Do Sul (Southern Brazil): Cytogenetic And Isozymic Evaluation As Support For Plant Breeding, M T. Schifino-Wittmann, L H. Cardoso De Freitas, A H. Lau

IGC Proceedings (1977-2023)

Native, naturalized and exotic Vicia and l.atliyrus species of Rio Grande do Sul were studied for chromosome numbers and meiotic behaviour, All species were diploid, with essentially regular meiosis and high pollen stainability. Interspecific differences for chiasma frequencies, chromosome and pollen grain size were detected. Polymorphism for chromosome number was observed in Vicia anguslilolia (2n = 10, 12, 14). Bsterase isozyme patterns are being analysed,


Morphogenetic And Structural Determinants Of Plant Regrowth After Defoliation, D F. Chapman, G Lemaire Aug 2024

Morphogenetic And Structural Determinants Of Plant Regrowth After Defoliation, D F. Chapman, G Lemaire

IGC Proceedings (1977-2023)

Responses of forage plants to defoliation can be delineated at two levels: physiological responses and morphological responses. Physiological responses are generally defined as occurring over short time-scales, whereas morphological responses are generally considered as being long-t<;rm. The extent to which physiological and morphological responses influence pasture characteristics and production depends on the defoliation regime, and the balance obtained between the supply and demand of growth resources by plants. Where defoliation is relatively infrequent and lax, plants may maintain balanced growth of root and shoot purely through short­term physiological responses. However, as defoliation severity increases, morphological adjustments are needed to ensure homeostatic, whole-plant growth. The adaptability of forage species to various points on the continuum of defoliation pressure from lenient to severe depends on their inherent morphological and physiological characteristics. We concentrate on morphogenetic and structural determinants of plant regrowth following defoliation, drawing out the important linkages with the physiological responses. We examine the relationships between plant morphogenesis and sward structure, placing particular emphasis on phcnotypic plasticity as a process whereby plant and population structure can alter to maintain homeostatic growth in response to variation in defoliation management. The imporlnnce of meristem positioning within the sward and of meristem activity, interacting with defoliation management, as determinants of plant production and persistence is discussed. Relationships between plant morphogenesis, herbage growth dynamics and barvestable herbage production are examined and we identify the collection of fundamental physiological and morphological information for a wider array of forage species as an important research goal for improving the productivity and sustainability of the world's grasslands.


Effect Of Nitrogen In Fertilizer In Combintation With Potassium And Phosphorus On Rangeland Yield In Cameroon, E T. Pamo, S Yonkeu Aug 2024

Effect Of Nitrogen In Fertilizer In Combintation With Potassium And Phosphorus On Rangeland Yield In Cameroon, E T. Pamo, S Yonkeu

IGC Proceedings (1977-2023)

A study was carried out at Wakwa Animal Research Station on the response of natural pasture to nitrogen fertilization in the presence of P 11osphorus and potassium, and a cutting frequency of 4 weeks. A Cmpletely randomized design with 6 replicates was used. Six fertiliser: 0, SO, 100, 150, 200, 2SO units of N/ha in association with 100 units of P and 100 units K after zero timing was applied after every cutting 0, 10, 20, 30, 40, SO units of Nlba were respectively added to plots which received 0, SO, 100, ISO, 200 and 250 units of Uha. Three …


Termites Have A Minor Role In The Decomposition Of Senescent Grass Tussocks In A Semi-Arid Woodland In Eastern Australia, J C. Noble Aug 2024

Termites Have A Minor Role In The Decomposition Of Senescent Grass Tussocks In A Semi-Arid Woodland In Eastern Australia, J C. Noble

IGC Proceedings (1977-2023)

Decomposition of dead tussocks of 2 grass species (Eragrostis eriopoda and Thyridolepis mitchellima) was studied with and without termites present, both in the absence of large ve.rtebrate herbivores, After 3 years, little tussock residues of either species remained icrespective of treatment, but E. er/opoda decayed much more rapidly than T. mitchellia11a during the first 8 months post mortem (c. 275 cf, 13 kg/ha/month respectively). Thereafter, rate of decay differed little between species. Overall, removal of termites had no significant effect, The data presented in this paper therefore suggest that abiotic processes are dominant influences mediating litter decomposition of …


A Bioeconomic Stocking Rate Model For The Semi-Arid Savanna Of Natal, South Africa, G P. Hatch, N M. Tainton Aug 2024

A Bioeconomic Stocking Rate Model For The Semi-Arid Savanna Of Natal, South Africa, G P. Hatch, N M. Tainton

IGC Proceedings (1977-2023)

Grazing trials were conducted on 2 sites located In semi-arid savanna of Natal. Three stocking strategies were applied at each site to provide light, intermediate and heavy stocking. Data collected over 5 seasons were used to.develop a bioeconomic stocking rate model. While individual animal performance and nett return per livestock unit (R/LSU) decreased with increased stocking, net return per ha (Riha) increased, Net return was significantly related (P 0, 01) to rainfall and stocking rate, while no significant effect of range condition was detected. Although Increased stocking may be justified In the short• term, this may be associated with both. …


Pasture Composition Influences Soil Erosion In Eucalyptus Woodlands Of Northern Queensland, J C. Scanlan, J G. Mcivor Aug 2024

Pasture Composition Influences Soil Erosion In Eucalyptus Woodlands Of Northern Queensland, J C. Scanlan, J G. Mcivor

IGC Proceedings (1977-2023)

Runoff and soil loss in grazed Eucalyptus woodlands of north Queensland were monitored over a 5-year period. As ground cover increased, runoff and soil loss decreased. When cover exceeded 50%, runoff and erosion were small. Ground cover was a function of standing dry mailer which decreased as tree cover and stocking rate increased and differed between pasture types. Simulated soil losses from these woodlands was <10-2800 kg/ha/year, and runoff was 5- 16 mm/year. Annual soil losses (simulated) were proportional to the square of the annual simulated runoff.


The Piosphere Effect Of A Goat Corral On The Productivity Of Arid Mediterranean-Type Rangelands In Northern Chile, S Lailhacar, A Mansilla, L Faundez, P Tonini Aug 2024

The Piosphere Effect Of A Goat Corral On The Productivity Of Arid Mediterranean-Type Rangelands In Northern Chile, S Lailhacar, A Mansilla, L Faundez, P Tonini

IGC Proceedings (1977-2023)

Arid rangelands of northern Chile consist of open shrub formations associated with a seasonal herbaceous stratum. Small pastoralists (comuneros) use the available fodder fer goat raising, by managing individual flocks under continuous grazing. Since each flock spends nights in a corral, a piosphere effect has evolved around it. Through radial transects and quadrals starling from the corral, cover, density, diversity and yield were determined for herbaceous and woody species. Except for shrub diversity and herbage yield, all other total variables showed significant increments with distance. When individual species were considered, different response trends were observed. Some species decreased, others increased, …


Tactical Grazing Can Help Maintain Stability Of Semi-Arid Wooded Grasslands, K C. Hodgkinson Aug 2024

Tactical Grazing Can Help Maintain Stability Of Semi-Arid Wooded Grasslands, K C. Hodgkinson

IGC Proceedings (1977-2023)

Arid and semi-arid wooded grasslands in Australia and elsewhere are prone to soil and plant productivity decline when used for pastoral production. Typically, degradation is characterised by woody plant increase, palatable perennial grass decline, unpalatable grass increase and lowered productive capacity of the soil, New grazing management that maintains productivity of plant and soil resources and sustains rehabilitation is required. In a grazing experiment on a mulga (Acacia aneura) woodland, grazing-induced death and impaired seed productivity were observed in palatable perennial grasses. A tactical grazing management to prevent an adverse change in pasture composition and productivity was designed involving progressively …


Management Strategies To Improve Indigenous Meat Goat Productivity In Semi-Arid Areas Of Southern Africa, L R. Ndlovu Aug 2024

Management Strategies To Improve Indigenous Meat Goat Productivity In Semi-Arid Areas Of Southern Africa, L R. Ndlovu

IGC Proceedings (1977-2023)

The semi-arid areas of southern Africa are characterised by low and erratic rainfall coupled with sandy soils which result in severe fluctuations in feed quality and quantity. Goats are an important component of farming systems in these areas but their meat production is constrained by shortage of feed in the dry season. Young goats are particularly vulnerable and management systems that prevent weight loss during the dry season are needed. Positive growth rates in kids· aged 8-60 weeks were obtained in response to feeding 200-400 g of Dolichos lablab (a drought-tolerant fodder) or Acacia lorti/is pods (a naturally occurring feed …


Herbage Yields Of Barley And Hungarian Vetch Or Hairy Vetch At Different Seeding Rates, M Munzur Aug 2024

Herbage Yields Of Barley And Hungarian Vetch Or Hairy Vetch At Different Seeding Rates, M Munzur

IGC Proceedings (1977-2023)

In a 2-year trial under dryland conditions on fallow land, an experiment was conducted to determine herbage quantity and quality of the mixtures of barley (Hordeum vulgare L.) and Hungarian vetch (Vicia pannonica Crantz.) or hairy vetch (Vicia villosa Roth.) grown at different seeding rates. Barley-vetch seeding rates were %: 100-0, 80-20, 60-40, 40-60, 20-80, 0-100. Seeding rates at 100% were 300 and 200 viable seeds/m2 for barley and vetches, respectively. Mean herbage dry matter (DM) and crude protein (CP) yields were different (P<0.05) among seeding rates with a 2-year average yield of 2058- 4742 kg DM/ha and 233-508 kg CP/ha. Botanical composition of the mixtures, based on weight, was generally 24-48% and 20-43% for Hungarian vetch and hairy vetch respectively, The best seeding rates in terms of herbage yield and crude protein yield were 20-80 or 40- 60, which are those equivalent to 60-160 or 120-120 seeds/m2 for barley and vetches, respectively. Mixtures of barley-vetches gave a better performance than barley or vetches grown alone.


An Approach For Testing The Ecological Amplitude Of Herbage Cultivars, B D. Campbell Aug 2024

An Approach For Testing The Ecological Amplitude Of Herbage Cultivars, B D. Campbell

IGC Proceedings (1977-2023)

A technique is described for testing the response of cultivars to environmental factors using crossed, controlled gradients of mineral nutrient supply and simulated grazing. The usefulness of the technique was tested by growing the perennial ryegrass (Lolium perenne L.) cultivar Melle and the cocksfoot (Dactylis glomerata L.) cultivar Sylvan in isolation and in a complex mixture on the matrix. Contour maps of the frequency of tillers of the cultivars after 2 years' growth indicated that Melle is better suited to high fertility, heavily stocked sites. The technique may be useful as a compact, standardised method for cultivar testing.