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Articles 151 - 180 of 16610

Full-Text Articles in Physical Sciences and Mathematics

A Traditional Exporter's Perspective Of Trade Reforms, N R. Mitchell Sep 2024

A Traditional Exporter's Perspective Of Trade Reforms, N R. Mitchell

IGC Proceedings (1993-2023)

The agriculture and trade policies which governments commonly have pursued over the last three decades, particularly governments in the large developed countries, have had a major impact on world patterns of production and trade in livestock and livestock products. This has been especially so for milk and dairy products where government involvement in markets has been most pervasive. One effect has been that the comparative advantages derived from the production of livestock products based on pasture feeding of animals \lave been suppressed or overridden. Reform of the international trading system for agricultural products now being developed in the GATT, and …


Impact Of Changing Trade Opportunities On Livestock Production In Developing Countries, J K. Camoens Sep 2024

Impact Of Changing Trade Opportunities On Livestock Production In Developing Countries, J K. Camoens

IGC Proceedings (1993-2023)

For the lesser developed countries (LDCs) and advanced countries (ACs), the paper identifies the determinants of "free" trade, analyses protectionism, examines the global trade picture with respect lo "free" trade, relates trade to production and the structure of demand, and finally predicts the impact of trade reforms. The analysis concludes that: (i) trade policies per se do not impact in any significant manner on domestic production or imports in the LDCs since world trade constitutes a small fraction of production; (ii) demand, and hence supply, of animal products are determined primarily by GNP, income distribution and price; (iii) grassland farming …


Development Of Grain-Saving, High Efficiency Pasture Animal Industry, Han Gui Qing Sep 2024

Development Of Grain-Saving, High Efficiency Pasture Animal Industry, Han Gui Qing

IGC Proceedings (1993-2023)

Grain-saving, high efficiency pasture-sustained (GSHEPS) animal industry, with its final purpose of profitable industry, is forage-orientated. This is a new fonn of operation based on advanced feeding management.


The Environment Of Glaciovolcanic Caves And Their Value As Planetary Analogues, Christian Stenner, Lee J. Florea, Linda Sobolewski, Andreas Pflitsch, Morgan Cable, Roberto Anitori, Richard E. Davis, Kathleen Graham, Glyn Williams-Jones Sep 2024

The Environment Of Glaciovolcanic Caves And Their Value As Planetary Analogues, Christian Stenner, Lee J. Florea, Linda Sobolewski, Andreas Pflitsch, Morgan Cable, Roberto Anitori, Richard E. Davis, Kathleen Graham, Glyn Williams-Jones

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


The Ecology Of Chemosynthesis In Submerged Coastal Caves, Robert Scharping, Michael Casso, Isabel Schaal, Paul Henderson, James Garey, Matthew Charette, John Pohlman, Stefan Sievert Sep 2024

The Ecology Of Chemosynthesis In Submerged Coastal Caves, Robert Scharping, Michael Casso, Isabel Schaal, Paul Henderson, James Garey, Matthew Charette, John Pohlman, Stefan Sievert

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


High Mountain Ecosystems And Snow Cover In A Changing Climate: For Better Or For Worse, Philippe Choler Sep 2024

High Mountain Ecosystems And Snow Cover In A Changing Climate: For Better Or For Worse, Philippe Choler

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Luminescence, Esr And Cl Characterisation Of Quartz Extracted From Granite Source Rocks And The Derived Sediments Used For Provenance Studies, Daniela Constantin, Aditi Dave, Serban Grecu, Zuzanna Kabacińska, Mihai Ducea, Petru Urdea, Alida Timar-Gabor Sep 2024

Luminescence, Esr And Cl Characterisation Of Quartz Extracted From Granite Source Rocks And The Derived Sediments Used For Provenance Studies, Daniela Constantin, Aditi Dave, Serban Grecu, Zuzanna Kabacińska, Mihai Ducea, Petru Urdea, Alida Timar-Gabor

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Revisiting The Chronology Of Loess In North America By Using Sar-Osl And Pirir Protocols, Anca Avram Sep 2024

Revisiting The Chronology Of Loess In North America By Using Sar-Osl And Pirir Protocols, Anca Avram

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Preliminary Analysis Of Quartz Using Scanning Electron Microscopy Techniques, Serban Constantin Grecu, Alida Timar-Gabor Sep 2024

Preliminary Analysis Of Quartz Using Scanning Electron Microscopy Techniques, Serban Constantin Grecu, Alida Timar-Gabor

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Hraunrásir: Exploring And Studying The Steaming Lava Tubes Of Fagradalsfjall Volcano (Iceland), Francesco Sauro, Riccardo Pozzobon, Martina Cappelletti, Bogdan P. Onac, Ana Zelia Miller, Groq Birkefeldt Moller Pedersen, Tommaso Santagata Sep 2024

Hraunrásir: Exploring And Studying The Steaming Lava Tubes Of Fagradalsfjall Volcano (Iceland), Francesco Sauro, Riccardo Pozzobon, Martina Cappelletti, Bogdan P. Onac, Ana Zelia Miller, Groq Birkefeldt Moller Pedersen, Tommaso Santagata

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Seasonal Changes In Forage Regrowth Yield And Quality Of Three Old World Bluestems, Larry M. White Sep 2024

Seasonal Changes In Forage Regrowth Yield And Quality Of Three Old World Bluestems, Larry M. White

IGC Proceedings (1993-2023)

Little information is available on differences in regrowth yield and quality among Old World bluestems (Bothriochloa spp.). Harvesting was staged such that 4-week regrowth of Caucasian (B. caucasica), cv. WW-Iron Master (D, ischaemum var. i.,ischaemum) and cv, Super Cauc (D. caucasica) was harvested each week from early May through mid-September to determine forage yield, ill vitro dry matter digestibility (IVDMD) and crude protein content of leaves and stems. Forage yield peaked in late June with WW-Iron Master, Caucasian, and Super Cauc producing 1280, 11S0 and 930 kg/ho/4 weeks of leaves and S00 200 and …


Herbage Production And Quality Of Rs2, A Quackgrass (Elytrigia Repens [L.]Neski.) X Bluebunch Wheatgrass (Pseudoroegneria Spicata [Pursh.] Love) Hybrid, M R. Haferkamp, D C. Adams, E E. Grings, P O. Currie Sep 2024

Herbage Production And Quality Of Rs2, A Quackgrass (Elytrigia Repens [L.]Neski.) X Bluebunch Wheatgrass (Pseudoroegneria Spicata [Pursh.] Love) Hybrid, M R. Haferkamp, D C. Adams, E E. Grings, P O. Currie

IGC Proceedings (1993-2023)

Fertiliser and mowing effects on herbage quality and yield of the RS2 hybrid were studied. Plants were fertilised with 0, 112 or 224 kg Nlha in spring 1988 and 1989, or with 112+112kg N/ha split in spring-summer, Plants were unmowed or mowed to a SO mm stubble height on selected dates in 1988 and 1989. Maximum standing crops (SC) of unmowed plants averaged 3000 kg/ha in 1988 and 5600 kg/ha in 1989; SC were increased 1000 kg/ha by fertilisation in 1989. Crude protein (CP) exceeded 120 g/kg in unmowed herbage in 1988 and decreased from 200 g/kg in May to …


Utilization Of Tall Fescue In Pure Stand, In Association With White Clover And In Complex Mixtures, S Badoux Sep 2024

Utilization Of Tall Fescue In Pure Stand, In Association With White Clover And In Complex Mixtures, S Badoux

IGC Proceedings (1993-2023)

Tall fescue (Festuca arundinacea Schreb.) was cultivated in pure stand, in association with white clover (Trifolium repens L.) and in various complex grass-legume mixtures. Forage yield and quality were always higher in associations with white clover than in tall fescue pure stands. However, under dry conditions, the balance between the two components was difficult to maintain. In more complex mixtures cocksfoot and tall fescue tended to become dominant and to produce a forage of lower quality. In mixtures of long duration, we replaced meadow fescue by tall fescue. Total yield over 3 years was improved; the digestibility of …


Use Of Plant Height For Determining The Nutritive Value, Yield And The Optimal Use Span Of Lucerne, Lother Schmidt Sep 2024

Use Of Plant Height For Determining The Nutritive Value, Yield And The Optimal Use Span Of Lucerne, Lother Schmidt

IGC Proceedings (1993-2023)

Determining the ·cutting date is important for high yield, good forage quality and longevity of lucerne (Medicago media Pers.) stands. Most recommendations for the optimal use date are based on the development ,stage. The results of research conducted over 9 years show that forage quality and the dry matter (DM) yield of luccrne, at the same, developmental stage, vary considerably, depending on weather conditions during the growth period. A better criterion is the plant height of lucerne. There was a highly significant correlation between plant height and the content of crude fibre, crude protein and DM. We recommend the …


Lamb And Steer Production From Continuously Grazed Alfalfa, Jerry D. Volesky, Daniel P. Mowrey Sep 2024

Lamb And Steer Production From Continuously Grazed Alfalfa, Jerry D. Volesky, Daniel P. Mowrey

IGC Proceedings (1993-2023)

Little is known about livestock production from alfalfa (Medicago saliva L,) under continuous grazing. Objectives were to determine lamb and steer performance, production and leaf-stem selection on continuously grazed alfalfa. Lambs and steers separately grazed 3 replicate pastures from late April through mid-August, 1991. Initial stocking densities were relatively heavy to utilise rapid spring growth after which livestock numbers were reduced to maintain alfalfa with a 20-cm stubble height. Season-long live-weight gains for the lambs and steers were 0.15 and 0.94 kg/day. Total production for lambs and steers was 557 and 529 kg/ha, Lamb diets generally contained a higher …


Impact Of Intermittent Clipping On Productivity, Forage Quality And Legume Persistence Of Reclaimed Mine Soils, M Collins, H B. Rice, R Turley, W O. Thom Sep 2024

Impact Of Intermittent Clipping On Productivity, Forage Quality And Legume Persistence Of Reclaimed Mine Soils, M Collins, H B. Rice, R Turley, W O. Thom

IGC Proceedings (1993-2023)

The materials used as plant growth media during surface mine· reclamation are frequently low in available N, P and K and are drought­prone. Legumes are included in reclamation seeding mixtures . because of their symbiotic N2-fixation ability but competition may prevent establishment or reduce persistence. A field study was conducted to test the hypothesis that intermittent clipping of these sites would reduce grass competition and thereby maintain legume stands. In 1990 and· 1991, 4 clipping treatments were imposed, providing intervals of 2, 4; and 6 weeks between harvests. Clipping at the 2- or 4-week intervals gave equal yields that were …


Sward Height In Grazing Management: Vertical Profiles In Forage Quality, J E. Johnston, A Singh, E A. Clark Sep 2024

Sward Height In Grazing Management: Vertical Profiles In Forage Quality, J E. Johnston, A Singh, E A. Clark

IGC Proceedings (1993-2023)

Vertical and temporal trends in herbage yield and quality were assessed in a study sown in 1989 near Elora, Ontario. In a replicated field trial with 0.1 ha paddocks, Hereford heifers rotationally grazed 2 swards to each of 2 residual grazing heights, namely, SO and 100 mm, with a requisite 200-2S0 mm entry height. Profiles in yield and in in vitro organic mailer digestibility (IVOMD) were developed from 6, 1500 cm2 quadrats per paddock, which were subjected to vertically stratified clipping, using sheep shears with a vacuum attachment. In 1990, obliging entry. at 200-2S0 mm stabilised herbage organic matter on …


Sward Height In Grazing Management: Species Adaptation, A Singh, J E. Johnston, E A. Clark Sep 2024

Sward Height In Grazing Management: Species Adaptation, A Singh, J E. Johnston, E A. Clark

IGC Proceedings (1993-2023)

Under continental, northern conditions, yield potential of species such as perennial ryegrass (Loli11111 pere,me L.) and white clover (Trifolium repe,is L.) is considered to be inferior to that of taller, coarser species such as orchardgrass, bromegrass, timothy and alfalfa. However, recent species evaluation bas stressed management regimes characteristic of conserved feed rather than pasture production, In a replicated trial, species performance and persistence in mixture were evaluated in response to sward height-based grazing management. Starling in 1990, 2 swards constructed predominantly of fine- or coarse-stemmed grasses were grazed rotationally by cattle, using a common 20-25 cm entry height and a …


Manipulation Of Perennial Ryegrass With The Plant Growth Regulator Mefluidide, M H. Foreman, R J. Field Sep 2024

Manipulation Of Perennial Ryegrass With The Plant Growth Regulator Mefluidide, M H. Foreman, R J. Field

IGC Proceedings (1993-2023)

In an attempt to increase the nutritive quality of herbage, the plant growth regulator mefluidide was applied at low rates (0.15-0.30 kg ai/ha) to pure stands of perennial ryegrass (Lolium perenne L.) in early spring. There was a reduction in total dry matter production of 35.8% at 0.3 kg ai/ha, but because reproductive development was significantly reduced there was a useful increase in the green leaf harvest component from 1.3% to 41.6% of total dry matter. High yields of green leaf were maintained for 100 days, in contrast to untreated swards which were composed largely of stem plus inflorescence …


Interaction Among Harvest Frequency, Fertilizer And Herbicide Use With Intensively Managed Alfalfa In The North-Central Usa, O B. Hesterman, J J. Kells, P L. Tiffin Sep 2024

Interaction Among Harvest Frequency, Fertilizer And Herbicide Use With Intensively Managed Alfalfa In The North-Central Usa, O B. Hesterman, J J. Kells, P L. Tiffin

IGC Proceedings (1993-2023)

This research evaluated effects of 2 alfalfa (Medicago sativa L,) cultivars (winter hardy and moderately winter hardy), 3 levels of fertiliser (none, medium, high), 3 levels of herbicide (none, medium, high), and 2 harvest systems ( 4 harvests and 5 harvests per year) on forage yield and quality, Five years (1987-1991) of an experiment in Michigan, USA, have been completed. During the first production year (1988). forage dry matter (DM) production was similar for the 5-harvest (15.2 Mg/ha) and the 4-harvest system (14.8 Mg/ha), During subsequent years, DM production was greater in the 4-harvest than in the 5-harvest system …


Seasonal Changes Of Daily Increase In Extended Sward Height, Dry Matter, Bulk Densities And Digestible Dry Matter Of Temperature Grasses, K Watanabe, K Kita, S Saiga Sep 2024

Seasonal Changes Of Daily Increase In Extended Sward Height, Dry Matter, Bulk Densities And Digestible Dry Matter Of Temperature Grasses, K Watanabe, K Kita, S Saiga

IGC Proceedings (1993-2023)

Under a regime of frequent cutting, seasonal changes of the daily increase in extended sward height, dry matter (OM) bulk densities and digestible dry matter (DOM) of perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.) and Kentucky bluegrass (Poa pratensis L.) were followed for 5 years. Seasonal changes of the daily increase in extended sward height, DM bulk densities (daily increase in OM/daily increase in extended sward height) and DOM (daily increase in DOM/daily increase in extended sward height) of the grasses had 3 peaks and 2 troughs, as the height and densities were depressed …


Effects Of Applied Nitrogen And Rest Period On Forage Production And Silage Quality, L Juan Carlos Dumont, A Francisco Lanuza Sep 2024

Effects Of Applied Nitrogen And Rest Period On Forage Production And Silage Quality, L Juan Carlos Dumont, A Francisco Lanuza

IGC Proceedings (1993-2023)

An experiment to analyse the effect of nitrogen (N) fertiliser and rest period initiation for silage making on permanent pasture was carried out. N fertiliser increased forage production, crude protein, neutral detergent fibre and ammonia-N. Shortening the intervals, by delaying the initiation of resting period, increased forage quality with only marginal decreases in dry matter (DM) production. Resting periods from the second week of September and cutting at the end of October or first week of November was appropriate in the Osorno area of Chile. The use of 60 kg N/ha is recommended. Two-cutting system must be considered in order …


Long-Term Management Of Vulpia In Pastures, A R. Leys, P M. Dowling, B Plater, M I. Smetham Sep 2024

Long-Term Management Of Vulpia In Pastures, A R. Leys, P M. Dowling, B Plater, M I. Smetham

IGC Proceedings (1993-2023)

Vulpia (Vulpia spp.) is a common weed of subterranean clover (Trifolium subterraneum L.)-based pastures throughout southern Australia, where it reduces productivity, contaminate's wool and injures livestock. Winter-cleaning pastures with simazine, and to a lesser extent spraying paraquat in spring to sterilise seed, gives good short-term control; however, vulpia produces large amounts of seed and can re-invade even dense subterraneum clover pastures. Re­invasion is least in pastures containing a companion grass. An integrated management system utilising grass in mixture with subterranean clover, livestock and the judicious use of herbicides, will be required to keep the vulpia content of pastures …


Vertical Distribution Of Botanical Components In Four Pastures Mixtures Grazed Solely By Goats, M J. Casey, R J. Lucas, D R. Stevens Sep 2024

Vertical Distribution Of Botanical Components In Four Pastures Mixtures Grazed Solely By Goats, M J. Casey, R J. Lucas, D R. Stevens

IGC Proceedings (1993-2023)

Four different grasses (perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth), cocksfoot (Dactylis glomerata L.) and timothy (Phelum pratense L.)) sown with white clover (Trifolium perenne L.) were evaluated under rotational goat grazing lo 10 cm in a cool temperate environment. Detailed measurements of the composition of vertical sward horizons, In spring, summer and autumn, showed significant differences in sward structure between pasture miX:tures. Prairie grass and cocksfoot swards were the tallest (>25 cm) in spring with the top of the sward dominated by grass leaf. The prairie grass sward was also taller …


The Ecosystem Of A Remarkable Glaciovolcanic Cave At Mount Meager, British Columbia, Canada, Christian Stenner, Kathleen Graham, Morgan Cable, Glyn Williams-Jones, Jared J. Clance, Jacob Shaffer, Jill Mikucki, Anna Szynkiewicz, Olivia Vinnes, Michael Paton, Jeremy Nash Sep 2024

The Ecosystem Of A Remarkable Glaciovolcanic Cave At Mount Meager, British Columbia, Canada, Christian Stenner, Kathleen Graham, Morgan Cable, Glyn Williams-Jones, Jared J. Clance, Jacob Shaffer, Jill Mikucki, Anna Szynkiewicz, Olivia Vinnes, Michael Paton, Jeremy Nash

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Effects Of Grazing Management On Grass Tiller Density Characteristics Of Ryegrass-White Clover Dairy Pasture, E R. Thom, A M. Bryant Sep 2024

Effects Of Grazing Management On Grass Tiller Density Characteristics Of Ryegrass-White Clover Dairy Pasture, E R. Thom, A M. Bryant

IGC Proceedings (1993-2023)

The characteristics of pastures receiving different systems of grazing management during September-May were examined over 3 years from September 1989. Three farmlets (each 10 0.8-ha areas) represented (i) rotational grazing every 30 days (September-May) (RG), (ii) fast rotations during spring (September-November) (SFR) and (iii) fast rotations during spring, summer and autumn (September­May) (SSFR). Pastures were predominantly perennial ryegrass (Lolium perenne L.) and white clover (Trlfolium repens L.) grazed by dairy cows. Large increases in grass tiller density occurred in SFR and SSFR areas after the first year compared with the rotationally grazed pastures, which have been maintained throughout …


Nitrogen Effects Of Barnyard Manure Applied On Andosol Grasslands In Eastern Hokkaido, T Saigusa, M Noshiro Sep 2024

Nitrogen Effects Of Barnyard Manure Applied On Andosol Grasslands In Eastern Hokkaido, T Saigusa, M Noshiro

IGC Proceedings (1993-2023)

Annual changes in the nitrogen (N) effects of barnyard manure (BM) were estimated on grassland of eastern Hokkaido, Japan. In pure' timothy (Phleum pratense L.) grasslands, they were as follows: in the first year after renovation, BM, when ploughed under, supplied an estimated 1 kg Nit manure; this value decreased to 0.5 kg Nit, and 0.3 kg Nit in the second and third year, respectively. When topdressed, BM supplied an estimated 1 kg Nit in the first year, and 0.5 kg Nit in the second year. In timothy-legume mixture, the amount of N supplied by BM to pure timothy …


Growth Kinetics Of Digitaria Decumbens After Defoliation By Cattle At Two Grazing Pressures, M Naves, P Cruz, A Malafosse, J P. Manteaux Sep 2024

Growth Kinetics Of Digitaria Decumbens After Defoliation By Cattle At Two Grazing Pressures, M Naves, P Cruz, A Malafosse, J P. Manteaux

IGC Proceedings (1993-2023)

Two regrowth cycles of an intensively managed Digitaria decumbens stand were studied. One followed high-stocked grazing by cows and their calves, and the other followed regrowth grazing by cows only. after weaning: Biomass, morphological composition, leaf area index and nitrogen were measured on 7 occasions between days O and 27 of growth. Residual biomass after the low grazing pressure (2403 kg DM/ha) was 4 times higher than after the high grazing pressure (633 kg DM/ha), mainly because more stems remained at the low grazing pressure (1220 kg DM/ha vs. 230 kg DM/ha). At both grazing pressures, growth of leaf and …


Productivity And Persistency Of Bromus Wildenowii Kunth Cv. Grasslands Matua In Japan, T Kanno, M Fukuyama, S Sato Sep 2024

Productivity And Persistency Of Bromus Wildenowii Kunth Cv. Grasslands Matua In Japan, T Kanno, M Fukuyama, S Sato

IGC Proceedings (1993-2023)

The study was conducted to evaluate herbage productivity, persistency and suitable management of prairie grass (Bromus willdenowll Kunth cv. Grasslands Matua) in Japan. Dry matter (DM) yields of S temperate grasses including prairie grass were compared. Pield plots were cut every month for 3 years. Annual DM yield of prairie grass was the highest in each year, but prairie grass was less persistent than the remaining grasses. In a grazing experiment, however, 1he seedlings of prairie grass appeared in flushes in autumn, and these ensured the persistency of prairie grass pasture, Under a forage conservation plus grazing regime, …


Forage Quality And Steer Performance On Tifton 78 And Coastal Bermudagrass Pastures, G M. Hill, G W. Burton, P R. Utley Sep 2024

Forage Quality And Steer Performance On Tifton 78 And Coastal Bermudagrass Pastures, G M. Hill, G W. Burton, P R. Utley

IGC Proceedings (1993-2023)

orage quality and weight gains were measured during a 3-year experimenl in which yearling sleers grazed replicated 0.81-ha paslures of Tiflon 78 (T), a Tiflon 44 x Callie Fl hybrid, or Coastal (C) bermudagrass (Cynodon dactylon [L.) Pers.). During 168-day grazing seasons, stocking rales were Increased as forage availability increased in spring and early summer resulting in mean slocking rales of 5.0 and 7.3 steers/ha, respectively, for C and T. Pastures were sampled al 28-day inlervals and in vitro dry matter disappearance (IVDMD) of available forage declined (P<0.01) for each bermudagrass with time, but seasonal mean IVDMD was higher (P<0.05) for T than C (T=57.4, C=56.5%). Steer average daily gains (ADO) were 15% higher (P<0.05) on T than on C pastures (C=0.59, T-0.68 kg), and gain/ha was 38.1%higher (P<0.01) for T than C (C=7l3, T=985 kg/ha). Superiority of Tifton 78 compared with Coastal has been verified in additional grazing experiments.