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2025

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Articles 1381 - 1410 of 2675

Full-Text Articles in Earth Sciences

Proceedings Of The 12th Research Symposium At Mammoth Cave National Park, Pat Kambesis Editor, Lee Anne Bledsoe Editor, Ana K. Celis Editor May 2025

Proceedings Of The 12th Research Symposium At Mammoth Cave National Park, Pat Kambesis Editor, Lee Anne Bledsoe Editor, Ana K. Celis Editor

Mammoth Cave Research Symposia

Proceedings of the 12th Research Symposium at Mammoth Cave National Park: Celebrating 100 Years of Scientific Research & Resource Management in the Mammoh Cave Region.


Remotely Sensed High-Resolution Soil Moisture And Evapotranspiration: Bridging The Gap Between Science And Society, Jingyi Huang, Vinit Sehgal, Laura V. Alvarez, Luca Brocca, Shuohao Cai, Rui Cheng, Xinghua Cheng, Jinyang Du, Bassil El Masri, K. Arthur Endsley, Yilin Fang, Jie Hu, Mahesh Jampani, Md Golam Kibria, Gerbrand Koren, Lingcheng Li, Laibao Liu, Jiafu Mao, Hernan A. Moreno, Angela Rigden, Mingjie Shi, Xiaoying Shi, Yaoping Wang, Xi Zhang, Joshua B. Fisher May 2025

Remotely Sensed High-Resolution Soil Moisture And Evapotranspiration: Bridging The Gap Between Science And Society, Jingyi Huang, Vinit Sehgal, Laura V. Alvarez, Luca Brocca, Shuohao Cai, Rui Cheng, Xinghua Cheng, Jinyang Du, Bassil El Masri, K. Arthur Endsley, Yilin Fang, Jie Hu, Mahesh Jampani, Md Golam Kibria, Gerbrand Koren, Lingcheng Li, Laibao Liu, Jiafu Mao, Hernan A. Moreno, Angela Rigden, Mingjie Shi, Xiaoying Shi, Yaoping Wang, Xi Zhang, Joshua B. Fisher

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

This paper reviews the current state of high-resolution remotely sensed soil moisture (SM) and evapotranspiration (ET) products and modeling, and the coupling relationship between SM and ET. SM downscaling approaches for satellite passive microwave products leverage advances in artificial intelligence and high-resolution remote sensing using visible, near-infrared, thermal-infrared, and synthetic aperture radar sensors. Remotely sensed ET continues to advance in spatiotemporal resolutions from MODIS to ECOSTRESS to Hydrosat and beyond. These advances enable a new understanding of bio-geo-physical controls and coupled feedback mechanisms between SM and ET reflecting the land cover and land use at field scale (3–30 m, daily). …


Temperature-Driven Air Circulation In Caves With Blind Passages, Chris Hendy Dr, David J. Merritt, Shannon Corkill, Cross Cross May 2025

Temperature-Driven Air Circulation In Caves With Blind Passages, Chris Hendy Dr, David J. Merritt, Shannon Corkill, Cross Cross

International Journal of Speleology

Two blind-passage show-caves in the Waitomo district of New Zealand, Ruakuri Cave and Aranui Cave, have been monitored for the impact of visitors on their environment, especially focusing on partial pressures of carbon dioxide because high levels cause speleothem degradation. In Ruakuri Cave, annual cycles of daily mean pCO2 correspond with annual cycles of visitor numbers, both peaking in summer. The origin of the high pCO2 had been assumed to be anthropogenic due to respiration from visitors. Prolonged intervals with no visitation during the Covid-19 pandemic saw the daily mean pCO2 continuing to show the annual cycle, …


Evaluating Subduction Zone Processes In Early Paleozoic Rocks Of The Northern Appalachian Orogen, John Mark Brigham May 2025

Evaluating Subduction Zone Processes In Early Paleozoic Rocks Of The Northern Appalachian Orogen, John Mark Brigham

Dissertations - ALL

The study of rocks presently exposed at the surface in mountain ranges such as the Appalachian Mountains can offer insight into the evolution of orogenic and subduction zone processes over geologic time. To better understand the timing, conditions (i.e., pressure and temperature), and tectonic setting of mineral formation in former subduction settings, geologists conduct geochronology, geochemistry, and thermobarometry analyses on rocks and minerals in paleo-subduction zones. This dissertation contains three chapters that focus on serpentinization, hydrothermal alteration of mafic rocks during serpentinization (rodingitization), and high-pressure metamorphism that occurred in a subduction setting during the first phase of the Appalachian Orogeny. …


Body Size Trends Of Late Devonian Dacryoconarid Tentaculitoids And Protocol Development For I/Ca Analysis In Corals By La-Icp-Ms, Ashley Prow-Fleischer May 2025

Body Size Trends Of Late Devonian Dacryoconarid Tentaculitoids And Protocol Development For I/Ca Analysis In Corals By La-Icp-Ms, Ashley Prow-Fleischer

Dissertations - ALL

Paleoclimatology provides context for understanding the timescales and animal responses to environmental change under modern climate change scenarios. The key drivers of climate variability are identified using proxies for environmental conditions. Biological archives are especially useful for linking changing conditions to ecosystem responses. This dissertation establishes the foundation for utilizing dacryoconarid microfossils as biostratigraphic indicators of environmental change in the Paleozoic. It also presents a protocol for measuring iodine-to-calcium (I/Ca) ratios—an established proxy for localized hypoxia—in coral skeletons using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Studying Paleozoic microfossils presents challenges due to the high degree of induration of …


Diel Patterns Of Biogeochemical Indicators In Tidally-Dominated Creeks, Juliana Calderone May 2025

Diel Patterns Of Biogeochemical Indicators In Tidally-Dominated Creeks, Juliana Calderone

Honors Theses

Marshes and swashes are vital environments as a controlling barrier between land affected by various pollutants and the ocean. Eutrophication and the effects of this process can be detrimental for the areas experiencing it. I am interested in ways areas that have little contact with human interactions compare to areas that are heavily urbanized, and whether either of these locations is at a higher risk for eutrophication. Using spectrophotometry and fluorometry, I analyzed samples collected from the relatively undeveloped and restricted-access locations of Waities Island Beach and Dunn Sound monthly for dissolved nutrients, and chlorophyll. At the time of sampling, …


From Fables To Facts: Discovering The World Through Stories And Science, Lucille Helen Vanek May 2025

From Fables To Facts: Discovering The World Through Stories And Science, Lucille Helen Vanek

Graduate Student Portfolios, Professional Papers, and Capstone Projects

From Fables to Facts: Discovering the World Through Stories and Science examines the integration of narrative storytelling and hands-on scientific exploration as a means of cultivating environmental literacy, ethical reflection, and sustained engagement with the natural world. Grounded in environmental philosophy, aesthetics, and ethics, the project draws on theoretical insights from Holmes Rolston III, Marcia Muelder Eaton, Allen Carlson, Arnold Berleant, and C. Thi Nguyen to develop a multidimensional model of education that unites imagination, cognition, and participatory experience. Implemented in diverse Montana community settings—including libraries, early learning centers, science museums, and faith-based organizations—the program paired fables, parables, and literary …


Magma Evolution And Eruptive History Of Three Fingered Jack: A Mafic Composite Volcano In The Central High Cascades Of Oregon, Javaria Aziz May 2025

Magma Evolution And Eruptive History Of Three Fingered Jack: A Mafic Composite Volcano In The Central High Cascades Of Oregon, Javaria Aziz

Dissertations and Theses

The central High Cascades graben in Oregon has been a center for mafic volcanism since its initiation. Three Fingered Jack is one of the larger mafic composite cones in the graben, located 20km south of Mount Jefferson. Three Fingered Jack erupted between 142.1 - 150.8ka, based on Ar40/Ar39 age dates. This study provides stratigraphic, compositional and petrographic evidence to understand the eruptive history of Three Fingered Jack and the processes involved in generating compositionally diverse basaltic andesites here.

The basaltic andesites of Three Fingered Jack show three compositional trends of magma evolution: 1) enrichment, 2) depletion and …


Recent U.S. Government Policy Literature On Critical And Strategic Minerals, Bert Chapman May 2025

Recent U.S. Government Policy Literature On Critical And Strategic Minerals, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Critical and strategic minerals have become increasingly important in U.S. government civilian and military policymaking in recent years. This is demonstrated by the heavy use of such minerals in many critical civilian and military infrastructures. This work will discuss how this subject has been addressed in laws, presidential documents, and works by government agencies along with congressional oversight committees and support agencies. It will stress how the United States is heavily dependent on strategic minerals from adversarial foreign countries such as China and will examine U.S. efforts to increase its ability to produce such materials in the United States by …


Impacts Of Water Conservation Cost-Share Programs On Irrigated Rice Extensification And Intensification In Critical Groundwater Areas Of The Arkansas Delta, Joshua Michael Blackstock, Oladipo S. Obembe, Aaron Shew, Michele Reba, Joseph M. Massey, Phillip R. Owens, Christopher D. Delhom May 2025

Impacts Of Water Conservation Cost-Share Programs On Irrigated Rice Extensification And Intensification In Critical Groundwater Areas Of The Arkansas Delta, Joshua Michael Blackstock, Oladipo S. Obembe, Aaron Shew, Michele Reba, Joseph M. Massey, Phillip R. Owens, Christopher D. Delhom

Geosciences Faculty Publications and Presentations

We analyzed the impact of government cost-shares for irrigation water management (IWM) conservation practices on the expansion and cropping intensity of rice (Oryza spp.) acreage in the Arkansas Delta. We used the correlated random effects probit model to control for unobserved effects and exploit changes in government spending over time. We found that government-spending impacts are heterogeneous across Critical Groundwater Area (CGA) designations. A 10% increase in government spending in counties fully within CGAs would reduce the propensity to expand rice acreage by 1.2 percentage points and the likelihood to rotate rice after rice by 7.6 percentage points. In counties …


Changes In Elephantgrass Plant Components With Maturity: 1. Percentage Dry Yield, P Mislevy, F G. Martin, M B. Adjei May 2025

Changes In Elephantgrass Plant Components With Maturity: 1. Percentage Dry Yield, P Mislevy, F G. Martin, M B. Adjei

IGC Proceedings (1977-2023)

Elephantgrass (Pennisetum purpureum Schum.) biomass can be a source of energy for tropical regions of the world because of its high dry matter production (Mislevy et al., 1986 ; Prine et al., 1987). Research has shown the production of energy (meth­ane) from biomass can be best understood through systems analysis methodology that integrates the availability of land, climate, production inputs, plant quality, etc. To assess avail­able technology and identify information gaps Biomass to Methane (Biomet) models have been developed to determine the impacts of basic growth processes in response to the crops environment (Mishoe et al., 1987). Biomass growth …


Teneurs En Constituants Parietaux Et En Matieres Azotees Des Ligneuz Fourragers D'Afrique Occidentale, A R. Kone, D Richard, H Guerin May 2025

Teneurs En Constituants Parietaux Et En Matieres Azotees Des Ligneuz Fourragers D'Afrique Occidentale, A R. Kone, D Richard, H Guerin

IGC Proceedings (1977-2023)

Dans !es pays intertropicaux d'Afrique, l'elevage est surtout extensif et l'alimentation du betail est essentiellement basee sur le paturage nature! ou la strate ligneuse (arbres, arbustes) fournit des fourrages verts pendant la periode seche de l'annee, periode pendant laquelle le tapis herbace est sous forme de paille sur pied. Les ligneux sont done tres importants dans l'alimentation des ruminants domestiques et ii est necessaire d'en connaitre la composition chimique comme dans le cas des fourrages herbaces.


Evaluation Of Tree Legumes Species At Different Agroclimatic Zones Of Indonesia, Mas'ud Panjaitan, R Jessop, W W. Stur May 2025

Evaluation Of Tree Legumes Species At Different Agroclimatic Zones Of Indonesia, Mas'ud Panjaitan, R Jessop, W W. Stur

IGC Proceedings (1977-2023)

The population of Indonesia is over 145 million and more than 56 % of them earn their living from agriculture (Bi. Stat. Ind., 1983). A major problem in the development of improved animal production has been the shortage of feed and the generally low nutritive value of tropical forages which limit livestock pro­duction in Indonesia (Asian Agriculture Survey, 1969). The production of feed of adequate quality for ruminants is an important consideration particularly for small holders. In many situations, nitrogen fixing legume trees can be used as a high protein feed supplement which improves the utilization of grasses and crop …


Valeur Nutritive D'Un Parcours Mixte A Acacia Cyanophylla, Atriplex Nummularia Et Medicago Arborea, Y Saadani, C Kayouli May 2025

Valeur Nutritive D'Un Parcours Mixte A Acacia Cyanophylla, Atriplex Nummularia Et Medicago Arborea, Y Saadani, C Kayouli

IGC Proceedings (1977-2023)

II existe tres peu de donnees concernant la valeur nutritive des arbustes fourragers ; les rares etudes realisees en Tunisie ont porte surtout sur leur productivite, la charge animale et sur leur appetence (Hamrouni et Sarson, 1975; Ben Boubaker, 1985). L'objectif de ce travail est d'etudier la valeur nutritive des feuilles et brindilles d' Acacia cyanophylla, d' A triplex nummula­ria et de Medicago arborea ainsi que leur contribution dans la ration de caprins et d'ovins.


Utilization Of Native Mediterranean Fodder Trees By Dairy Goats, M Meuret May 2025

Utilization Of Native Mediterranean Fodder Trees By Dairy Goats, M Meuret

IGC Proceedings (1977-2023)

Few data are available on utilization of fodder trees and shrubs by lactating goats. In most cases, predictions of animal performances on the basis of recommendations obtained from standard reference trials, do not correspond with production results achieved on the farm. Using measurements in digesti­bility cages and on rangelands (chromic oxide marker), we recorded intake, apparent digestibility of diets and perform­ances of goats well used to rangelands and browsing fresh oak foliage (Quercus ilex and Quercus pubescens).


Phenols As Defensive Compounds In Birch (Betula Spp.) Metabolism Of Platyphylloside In Goats, Rabbits And Hares, R T. Palo, G Iason, P G. Knutsonn May 2025

Phenols As Defensive Compounds In Birch (Betula Spp.) Metabolism Of Platyphylloside In Goats, Rabbits And Hares, R T. Palo, G Iason, P G. Knutsonn

IGC Proceedings (1977-2023)

Herbivores of the boreal forest like moose (Alces alces), hares (Lepus spp.) and birds (Tetranoidae) use birch as a major feed source. The tree is of medium preference to the animals and is low in available nutrients for most of the year. Apart from a high amount of lignified cell walls it also contains con­siderable amounts oflow molecular phenolic substances (Palo, 1984). A herbivore feeding on birch could thus be excepted to ingest large amounts of phenols. These are in general enough fat soluble to enter animal cells expected to ingest large amounts of …


Forage Production And Nutritive Value Of Leucanea Leucoephala In Southern Puerto Rico, L E. Tergas, R Milton Martinez, A V. Mendez Cruz May 2025

Forage Production And Nutritive Value Of Leucanea Leucoephala In Southern Puerto Rico, L E. Tergas, R Milton Martinez, A V. Mendez Cruz

IGC Proceedings (1977-2023)

Leucaena leucocephala (L.) is a perennial schrub native to Mexico, Central America and the Caribbean, considered by investigators as a valuable forage legume because of its capacity for high production of digestible forage with a high protein content and tolerance to drought in semiarid regions with annual rainfall less than 1,000 mm (Skerman, 1977). The soil fertility of the semiarid region in southern Puerto Rico is adequate, but rainfall distribution is limiting for forage production and nutritive value. There is a demand for a suit­able and inexpensive source of high quality forage to improve the diet of the grazing cattle …


Effect Of Chemical Composition Of Roughages On Their Degradation Characteristics In The Rumen And Their Relationship With The < In Vitro > Organic Matter Digestibility, S Lopez, Dolores Carro, J S. Gonzales, Conchita Carpintero May 2025

Effect Of Chemical Composition Of Roughages On Their Degradation Characteristics In The Rumen And Their Relationship With The < In Vitro > Organic Matter Digestibility, S Lopez, Dolores Carro, J S. Gonzales, Conchita Carpintero

IGC Proceedings (1977-2023)

The microbial fermentation of feeds in the reticulo-rumen allows ruminants the utilization of feeds with amounts of cell wall components, i.e. roughages. This rumen fermentation can be affected by the feed chemical composition and numerous techniques have been developed for its determination (Van Soest, 1982). The objective of the present work is to investigate the effect of the chemical composition of forages preserved under differ­ent methods on their degradation characteristics in the rumen determined by the « in sacco » method and to study the rela­tionships between the « in vitro» organic matter digestibility (IVOMD) and the rumen degradability.


Rumen Degradation Of Various Grass Species At Different Stages Of Growth, L J. Halliday May 2025

Rumen Degradation Of Various Grass Species At Different Stages Of Growth, L J. Halliday

IGC Proceedings (1977-2023)

The species and cultivars sown depends on the farming sys­tem practiced. These developing swards are however, always invaded by native species including Agrostis, Paa and Festuca spp. which are generally referred to as 'weed' grasses. While the merits of Lolium spp. are well documented (Minson et al. 1960; Norton, 1982) information on the weed grasses is limited (Hag­gar, 1976). The potential for milk and meat production is dependent on the supply of utilizable nutrients to the animal's tissues which in turn is largely governed by the ability of rumen microbes to degrade plant cell walls. Although the degradability of dry …


Apparent Digestibility, Dynamics Of Rumen Fermentation And Sites Of Digestion Of Hays Of Leucaena Leucocephala (Lam) De Wit Cv. Peru, N M. Rodreiguez, I Borges May 2025

Apparent Digestibility, Dynamics Of Rumen Fermentation And Sites Of Digestion Of Hays Of Leucaena Leucocephala (Lam) De Wit Cv. Peru, N M. Rodreiguez, I Borges

IGC Proceedings (1977-2023)

Protein deficiency, among others, is a common problem for livestock production in tropical regions. The use oflegumes has been suggested as a solution and Leucaena leucocephala has shown a great potential due to its capacity of nitrogen (N) fix­ation and dry matter (DM) production (NAS, 1984). However, very little is known about its nutritive value regarding its protein-energy balance and the process of digestion. The present work aimed the evaluation of the nutritive value of hays of Leucaena leucocephala cut at two stages of growth, through trials of apparent digestibility, dynamics of rumen fer­mentation and partition of digestion.


In Situ Degradation Of Cell Wall Neutral Sugars Of Normal And Brown Midrib Sorghum X Sudangrass Hybrids, K J. Moore, J O. Fritz, E H. Jaster May 2025

In Situ Degradation Of Cell Wall Neutral Sugars Of Normal And Brown Midrib Sorghum X Sudangrass Hybrids, K J. Moore, J O. Fritz, E H. Jaster

IGC Proceedings (1977-2023)

The nutritive value of forage for ruminants is limited by the digestibility of the complex polysaccharides cellulose and hemicellulose by rumen microbes. In grasses, the polysacchar­ide fraction of the cell wall is composed largely of polymers of neutral sugars and to a lesser extent uronic acids. Cellulose is a high molecular weight linear polymer of B-1 ➔ 4) linked D­gluco-pyranose units. Hemicellulose is a complex mixture of linear and branched-chain heteropolymers containing xylose, arabmose, mannose, galactose, glucose, and uronic acids (Van Soest, 1982). Lignification of the cell wall is a primary factor limiting the digestion of cell wall polysaccharides. Close …


Feed Evaluation Using Mobile Dacron Bags And Influences Of The Diet Composition, H Anzola, F N. Owens May 2025

Feed Evaluation Using Mobile Dacron Bags And Influences Of The Diet Composition, H Anzola, F N. Owens

IGC Proceedings (1977-2023)

The Mobile Nylon Bag (MNB) technique has been used successfully in protein nutrition studies with swine (Sauer et al., 1983) to determine amino acid availability from protein in specific feedstuffs. Canadian researchers also have tested this technique to predict site of digestion in ruminants (Kirkpatrick and Kennelly, 1987). Differences in small intestinal digestion may explain why animal responses differ to dietary protein sources which have similar ruminal escape values (Owens, 1986). The MNB holds promise to appraise the intestinal avail­ability of undegraded dietary protein though further develop­mel).t and testing are needed. The objective of this experiment was to examine the …


Prediction Of Digestibility And Protein From Growing Degree-Days For Crested And Western Wheatgrass, A` B. Franck, J F. Karn May 2025

Prediction Of Digestibility And Protein From Growing Degree-Days For Crested And Western Wheatgrass, A` B. Franck, J F. Karn

IGC Proceedings (1977-2023)

Morphological development of crops, including cool-season forage grasses, is mainly a function of air temperature. Mor­phological development of plants has been predicted from ther­mal units expressed as growing degree-days (GDD) (Franck, 1985 ; Wang, 1960). The use of thermal units also provides a predictive measure for managing forages based on growth stages rather than dates. However, forage digestibility ��nd crude protein (CP) content generally decrease as morphological development and time increase (Kamstra, 1973 ; Kilcher and Troelsen, 1973). The relationship between thermal units and forage digestibility and CP has not been defined for crested and western wheatgrasses. The primary purpose …


Forage Quality Of Coast Cross 1 Bermudagrass On Intestinal Digestion Of Dietary Amino Acids, G Coto, Hanna Meier, Patrica Malgarez May 2025

Forage Quality Of Coast Cross 1 Bermudagrass On Intestinal Digestion Of Dietary Amino Acids, G Coto, Hanna Meier, Patrica Malgarez

IGC Proceedings (1977-2023)

The aim of this work was to study the digestibility of dietary amino acids found in the fibrous material, considering the qual­ity of the forage offered as the sole feeding source.


Sites Of Digestion Of Nitrogen Of Hays Made With The Tropical Legume Neonotonia Wightii, R R. Vera, E A. Pizarro, A Toscano, N M. Rodriguez May 2025

Sites Of Digestion Of Nitrogen Of Hays Made With The Tropical Legume Neonotonia Wightii, R R. Vera, E A. Pizarro, A Toscano, N M. Rodriguez

IGC Proceedings (1977-2023)

Tropical pasture species are of well-known lower quality than temperate species and there is evidence that some tropical legumes may contain antiquality factors that reduce further their nutritive value. Nonetheless, the nutritive value of Neonotonia wightii is generally moderate to high (Pizarro et al., 1983 ; Ribeiro et al., 1980), although there is little information on the factors that affect its quality, and none on the rate and sites of digestion within the gastrointestinal tract of ruminants. The aim of the work reported here was to examine the effect of age on the chemical composition, apparent digestibility and sites of …


Kinetic Study Of The Rumen Microbial Degradation Of Lucerne And Italian Ryegrass Observed By Scanning Electron Microscopy, E Grenet, J Jamot May 2025

Kinetic Study Of The Rumen Microbial Degradation Of Lucerne And Italian Ryegrass Observed By Scanning Electron Microscopy, E Grenet, J Jamot

IGC Proceedings (1977-2023)

For the same digestibility cell wall contents of legumes and grasses differ ; their histological structure is not the same and this may account for the differences in rumen degradation. We studied by scanning electron microscopy (SEM) the histologi­cal structure of these plants with regard to stages of maturity, and their kinetic degradation in the rumen.


Fermentation Characteristics Of Temperate Forage Stems Digested In Vitro, D R. Buxton May 2025

Fermentation Characteristics Of Temperate Forage Stems Digested In Vitro, D R. Buxton

IGC Proceedings (1977-2023)

Digestion of herbage by ruminants is limited primarily by concentration of neutral-detergent fiber (NDF) in herbage and degradability of this cell-wall material. Because mature stems usually contain more NDF than immature stems or leaves the proportion of stems approaching maturity is normally' the dominant morphological factor that determines digestibility of herbage (Buxton and Hornstein, 1986). On the basis of digesti­bility, NDF can be divided into two fractions: potentially digestible NDF (PDNDF) and indigestible NDF (IDNDF; Mertens and Ely, 1982), which is not digested regardless of length of fermentation. Digestion of NDF can be characterized by a two-stage process involving a …


Nitrogen And Organic Matter Disappearance In The Digestive Tract Of Sheep Grazing Three Winter Foggages, W A. Van Niekerk, H H. Meissner, E B. Spreeth, I S. Conradie May 2025

Nitrogen And Organic Matter Disappearance In The Digestive Tract Of Sheep Grazing Three Winter Foggages, W A. Van Niekerk, H H. Meissner, E B. Spreeth, I S. Conradie

IGC Proceedings (1977-2023)

Animal production in the tropics and subtropics is limited by poor intake. This results because of high cell wall content and poor digestibility of tropical forages (Minson & McLeod, 1970). During the dormant (winter) season these negative effects were exaggerated. Also, N declines resulting in a further reduction in intake. The questions addressed here were whether winter foggage of improved subtropical pastures could be ben­eficial and secondly, how three species adapted to the drier areas of South Africa, compare in this regard.


Nutritive Value Of Perennial Ryegrass Swards Grazed By Sheep In Autumn In The Uk, J A. Milne, H Dove, A M. Sibbald May 2025

Nutritive Value Of Perennial Ryegrass Swards Grazed By Sheep In Autumn In The Uk, J A. Milne, H Dove, A M. Sibbald

IGC Proceedings (1977-2023)

A knowledge of the nutrient supply from grazed herbage for ewes in the autumn in N. Europe is required to predict the consequences for their subsequent reproductive performance. Herbage intake has been found to be positively related to sward height over this period at low sward heights but there is no information over a wider range of heights, on the amounts of non-ammonia nitrogen (NAN) available for absorption in the small intestine nor on the digestion of organic matter in the rumen. Experiments on frozen or artificially dried herbage harvested in the autumn have given variable results for the amounts …


Influence Due Niveau De Fertilization Azotee Sur La Degradabilite De L'Azote De La Fetuque Elevee Recoltee En Vert, P Le Goffe, R Verite, G Lemaire May 2025

Influence Due Niveau De Fertilization Azotee Sur La Degradabilite De L'Azote De La Fetuque Elevee Recoltee En Vert, P Le Goffe, R Verite, G Lemaire

IGC Proceedings (1977-2023)

Il est connu que la fertilisation azotee ameliore non seule­ment la biomasse produite mais aussi la teneur en azote de la plante; cependant certains auteurs la soup9onnent de reduire le flux d'azote duodenal (Armstrong, 1974). Cette diminution de la valeur azotee reelle pourrait s'expliquer par la baisse des syntheses de proteines microbiennes et/ou !'augmentation de la degradation ruminale des proteines de l'herbe. Dans ce travail, l'effet de 2 niveaux de fertilisation azotee, appliques sur 4 cycles successifs d'une fetuque, sur la degradabilite de l'azote de la plante verte a ete etudie par 3 methodes differentes ; de plus l'incidence du …