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Nitrogen Dynamics In Three Contrasting Grassland Systems: Implications For Pasture Productivity And The Potential For Environmental Pollution, B E. Ruz-Jerez, R E. White, P Roger Ball Sep 2024

Nitrogen Dynamics In Three Contrasting Grassland Systems: Implications For Pasture Productivity And The Potential For Environmental Pollution, B E. Ruz-Jerez, R E. White, P Roger Ball

IGC Proceedings (1977-2023)

Nitrogen (N) dynamics were compared in 3 contrasting grassland systems (2 legume-based and I receiving fertiliser N) in a cool temperate region of New Zealand. The study was concentrated on the various N transfers that occurred during and after grazing. Critical periods for N loss by different processes have been identified, allowing a more comprehensive understanding of the role of N in the productivity of different types of pasture, and the potential for environmental pollution, Calculation of N inputs and outputs for the three pastures indicated that the two legume-based systems were more or less in balance, but in the …


Reduction Of Nutrient Losses For Dairy Farms, With Emphasis On Nitrogen, W Luten, D J. Den Boer Sep 2024

Reduction Of Nutrient Losses For Dairy Farms, With Emphasis On Nitrogen, W Luten, D J. Den Boer

IGC Proceedings (1977-2023)

Recently the Dutch government presented several policy papers in which standards are given for maximum allowed emissions to air, groundwater and surface water. Depending on the farm situation an optimum combination of measures in relation to housing, slurry storage, slurry and fertiliser application, and composition of the ration can be taken. In general a better use of nutrients from animal manure by applying slurry with low emission techniques in the growing season and a reduction of the stocking rate by a higher milk production per cow are the most effective and cheapest measures to reach these targets. There is a …


Use Of Pasture As A Receivers For Swine Lagoon Effluent, J P. Mueller, J C. Barker, J P. Zublena, M H. Poore, R W. Harvey, J T. Green Sep 2024

Use Of Pasture As A Receivers For Swine Lagoon Effluent, J P. Mueller, J C. Barker, J P. Zublena, M H. Poore, R W. Harvey, J T. Green

IGC Proceedings (1977-2023)

Swine waste management-cattle grazing systems were monitored on 2 North Carolina farms from 1990-1992, Farmers co-operated directly in the project by furnishing land, labour, equipment and cattle and by maintaining records of grazing and waste applications. Local county agricultural extension agents helped with management decisions, record­keeping and co-ordinating activities among project participants. On a fann where waste was applied to pastures for 5 years, soil N in the upper l m averaged from 230-500 kg/ha, NO3 -N in the forage remained above 10 g/kg for the grazing season and 2 of 4 test wells recorded NO3 levels above 10 mg/I. …


Pastoral Systems Of Central Himalaya: How Long Will They Survive?, K S. Rao, K G. Saxena Sep 2024

Pastoral Systems Of Central Himalaya: How Long Will They Survive?, K S. Rao, K G. Saxena

IGC Proceedings (1977-2023)

Pastoral systems of Central Himalaya are very old and until recent time were in balance with environment, Recent changes in socio­political setup have drastically altered the status of these systems. The change of political power in trans-Himalayan Tibetean plateau has resulted in closure of international boarders, thus taking away the mercantile aspects of pastoralists and reducing pastoral area. Increased human disturbances on fragile Himalayan marginal lands and excessive onslaught on forests for fuel and fodder by the sedentary population has resulted in degradation and non-productive grasslands which do not help pastoralists sustain existing systems. Changes in relations between migratory pastoralists …


A Preliminary Discussion Of The Management And Administration Of Yunwu Mountain Natural Grassland Reserve In China, Zhao Zhiyi, Yang Ailian Sep 2024

A Preliminary Discussion Of The Management And Administration Of Yunwu Mountain Natural Grassland Reserve In China, Zhao Zhiyi, Yang Ailian

IGC Proceedings (1977-2023)

The advantages and problems encountered in the establishment of a grassland reserve are described. The conflicts between local farmers' requirement to feed and water livestock and the conservation strategy of natural grassland are discussed.


Effect Of Sewage Sludge On The Mineral Composition Of Corn, Arthur E. Peterson, P E. Speth, P L. Schlecht Sep 2024

Effect Of Sewage Sludge On The Mineral Composition Of Corn, Arthur E. Peterson, P E. Speth, P L. Schlecht

IGC Proceedings (1977-2023)

For the past 12 years, digested sewage sludge from the Milwaukee Metropolitan Sewerage District has been applied to a Plano silt loam (prairie) soil near Elkhorn, Wisconsin, and corn raised as the indicator crop. The corn has been harvested as silage and fed to dairy cnttle. The amounts of macro-, micro-, and heavy metals contained in this forage were compared with the amounts contained in the untreated areas, and in the forage produced by a sustainable agriculture study on the same experimental station. None of the heavy metals have moved out of the plough layer (lop 25 cm). The uptake …


Sustainable Direction For Resource Management An Assessment Of The Regional Council Role, Allan Lohrey Sep 2024

Sustainable Direction For Resource Management An Assessment Of The Regional Council Role, Allan Lohrey

IGC Proceedings (1977-2023)

The 1980s has seen an increased world awareness of the concept of sustainability. In 1991 New Zealand enacted the Resource Management Act (RMA) which reflected society's concern for a need to consider future generations when making decisions relating to the use of natural resources. Regional councils have been allocated the role within the Act to promote sustainable management at the regional level. The short term challenge to regional councils is to manage resources in manner which strikes a pragmatic balance between the ongoing needs of society and the need to provide resources for future generations. Regional councils will know they …


Application Of Dairy Manure On Alfalfa, Stephen J. Herbert, Jayarm Daliparthy, P L.M Veneman Sep 2024

Application Of Dairy Manure On Alfalfa, Stephen J. Herbert, Jayarm Daliparthy, P L.M Veneman

IGC Proceedings (1977-2023)

Applying dairy manure to alfalfa (Medicago sativa L.) as ,in alternative 10 excess application to· corn (Zea mays L.) may reduce nitrate pollution of groundwater. Field experiments were conducted at 2 sites in Massachusetts, USA, lo study the impact or dairy manure application to alfalfa on forage yield, weed infestation· and nitrate movement. Treatments were an unfertilized (no N) check.· plot, low and high manure (112 and 336 kg N/ha/year equivalerit), and low and high N fertiliser (112 and 336 kg N/ha/year from NH4NO3),'. Liquid dairy manure was applied 10 • alfalfa immediately· after 1st· cutting during spring …


Axonal Injury, Sleep Disturbances, And Memory Following Traumatic Brain Injury, Emma M. Tinney, Goretti España-Irla, Aaron E. L. Warren, Lauren N. Whitehurst, Alexandra N. Stillman, Charles H. Hillman, Timothy P. Morris, Alzheimer’S Disease Neuroimaging Initiative Sep 2024

Axonal Injury, Sleep Disturbances, And Memory Following Traumatic Brain Injury, Emma M. Tinney, Goretti España-Irla, Aaron E. L. Warren, Lauren N. Whitehurst, Alexandra N. Stillman, Charles H. Hillman, Timothy P. Morris, Alzheimer’S Disease Neuroimaging Initiative

Neurology Faculty Publications

Objectives: Traumatic brain injury (TBI) is associated with sleep deficits, but it is not clear why some report sleep disturbances and others do not. The objective of this study was to assess the associations between axonal injury, sleep, and memory in chronic and acute TBI. Methods: Data were acquired from two independent datasets which included 156 older adult veterans (69.8 years) from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) with prior moderate- to-severe TBIs and 90 (69.2 years) controls and 374 (39.6 years) from Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) with a recent mild TBI (mTBI) and 87 controls …


Nitrate Removal By Floating Treatment Wetlands Under Aerated And Unaerated Conditions: Field And Laboratory Results, Jenna Mccoy, Matt Chaffee, Aaron Mittelstet, Tiffany L. Messer, Steve Comfort Sep 2024

Nitrate Removal By Floating Treatment Wetlands Under Aerated And Unaerated Conditions: Field And Laboratory Results, Jenna Mccoy, Matt Chaffee, Aaron Mittelstet, Tiffany L. Messer, Steve Comfort

Earth and Environmental Sciences Faculty Publications

Urban and storm water retention ponds eventually become eutrophic after years of receiving runoff water. In 2020, a novel biological and chemical treatment was initiated to remove accumulated nutrients from an urban retention pond that had severe algae and weed growth. Our approach installed two 6.1 m × 6.1 m floating treatment wetlands (FTWs) and two airlift pumps that contained slow-release lanthanum composites, which facilitated phosphate precipitation. Four years of treatment (2020–2023) resulted in median nitrate-N concentrations decreasing from 23 μg L−1 in 2020 to 1.3 μg L−1 in 2023, while PO4-P decreased from 42 μg L−1 to 19 μg …


Coal Ash Triggers An Elevated Temperature Landfill Development: Lessons From The Bristol Virginia Solid Waste Landfill Neighboring Community, Reagan Patton Witt, Marcelo I. Guzman Sep 2024

Coal Ash Triggers An Elevated Temperature Landfill Development: Lessons From The Bristol Virginia Solid Waste Landfill Neighboring Community, Reagan Patton Witt, Marcelo I. Guzman

UK CARES Faculty Publications

Landfills for disposing of solid waste are designed, located, managed, and monitored facili- ties expected to comply with government regulations to prevent contamination of the surrounding environment. After the average life expectancy of a typical landfill (30 to 50 years), a large investment in the construction, operation, final closure, and 30-year monitoring of a new site is needed. In this case study, we provide a holistic explanation of the unexpected development of elevated temperature landfills (ETLFs), such as that in the city of Bristol (United States) on the border of the states of Virginia and Tennessee, including the initial role …


A Framework For Modeling The Impacts Of Adaptive Search Intensity On The Efficiency Of Abundance Surveys., Laura Jiménez, John R Fieberg, Michael Mccartney, Jake M Ferguson Sep 2024

A Framework For Modeling The Impacts Of Adaptive Search Intensity On The Efficiency Of Abundance Surveys., Laura Jiménez, John R Fieberg, Michael Mccartney, Jake M Ferguson

Biology Faculty Publications

When planning abundance surveys, the impact of search intensity on the quality of the density estimates is rarely considered. We constructed a time-budget modeling framework for abundance surveys using principles from optimal foraging theory. We link search intensity to the number of sample units surveyed, searcher detection probability, the number of detections made, and the precision of the estimated population density. This framework allowed us to determine how a searcher should behave to produce optimized density estimates. Using data collected from quadrat and removal surveys of zebra mussels (Dreissena polymorpha) in central Minnesota, we applied this framework to evaluate potential …


Predicting The Association Of Metabolites With Both Pathway Categories And Individual Pathways, Erik D. Huckvale, Hunter Moseley Sep 2024

Predicting The Association Of Metabolites With Both Pathway Categories And Individual Pathways, Erik D. Huckvale, Hunter Moseley

Markey Cancer Center Faculty Publications

Metabolism is a network of chemical reactions that sustain cellular life. Parts of this metabolic network are defined as metabolic pathways containing specific biochemical reactions. Products and reactants of these reactions are called metabolites, which are associated with certain human-defined metabolic pathways. Metabolic knowledgebases, such as the Kyoto Encyclopedia of Gene and Genomes (KEGG) contain metabolites, reactions, and pathway annotations; however, such resources are incomplete due to current limits of metabolic knowledge. To fill in missing metabolite pathway annotations, past machine learning models showed some success at predicting the KEGG Level 2 pathway category involvement of metabolites based on their …


Perspectives On The Clinical Use Of Anti-Amyloid Therapy For The Treatment Of Alzheimer's Disease: Insights From The Fields Of Cancer, Rheumatology, And Neurology, Gregory Jicha, Erin Abner, Elif Pinar Coskun, Mark Huffmyer, Thomas Tucker, Peter T. Nelson Sep 2024

Perspectives On The Clinical Use Of Anti-Amyloid Therapy For The Treatment Of Alzheimer's Disease: Insights From The Fields Of Cancer, Rheumatology, And Neurology, Gregory Jicha, Erin Abner, Elif Pinar Coskun, Mark Huffmyer, Thomas Tucker, Peter T. Nelson

Neurology Faculty Publications

Introduction: The advent of disease-modifying therapies for Alzheimer’s disease (AD) has raised many questions and debates in the field as to the clinical benefits, risks, and costs of such therapies. The controversies have resulted in the perception that many clinicians are apprehensive about prescribing these medications to their patient populations. There also remains widespread uncertainty as to the economic impact, cost benefit ratio, and safety oversight for use of these medications in standard clinical care settings.

Methods: To contextualize such issues, the present study compared anti-amyloid biologic therapy (lecanemab) to four commonly used biologic agents in other fields, including trastuzumab …


Analysis Of The Thermal Aging Kinetics Of Tallow, Chicken Oil, Lard, And Sheep Oil, Yun-Chuan Hsieh, Hao Ouyang, Yulin Zhang, Donyau Chiang, Fuqian Yang, Hsin-Lung Chen, Sanboh Lee Sep 2024

Analysis Of The Thermal Aging Kinetics Of Tallow, Chicken Oil, Lard, And Sheep Oil, Yun-Chuan Hsieh, Hao Ouyang, Yulin Zhang, Donyau Chiang, Fuqian Yang, Hsin-Lung Chen, Sanboh Lee

Chemical and Materials Engineering Faculty Publications

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid–base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 ◦C to 180 ◦C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics. The evolutions of the color centers, defects for dynamic viscosity, and electric dipoles follow second-order, first-order, and zero-order kinetics, respectively. …


Checklist And Key To Species Of Stink Bugs (Hemiptera, Heteroptera, Pentatomidae) Of Kentucky, United States Of America, Armando Falcon-Brindis, Raul Villanueva Sep 2024

Checklist And Key To Species Of Stink Bugs (Hemiptera, Heteroptera, Pentatomidae) Of Kentucky, United States Of America, Armando Falcon-Brindis, Raul Villanueva

Entomology Faculty Publications

Stink bugs (Heteroptera: Pentatomidae) have received a lot of attention as there are many economically important pest species. However, the status of species richness, distribution, and taxonomy remain overlooked and outdated in Kentucky (USA). Having such information at a regional scale is crucial to allow the development of suitable pest management and conservation programs. Here, the stink bug fauna of Kentucky was ex- amined from museum specimens, literature, and public online repositories. Overall, 42 species in 28 genera and three subfamilies (Asopinae, Podopinae, and Pentatominae) are listed from Kentucky. Thirteen species are new records for Kentucky, 10 species are considered …


Deciphering Cellular Heterogeneity In Spodoptera Frugiperda Midgut Cell Line Through Single Cell Rna Sequencing, Surjeet Kumar Arya, Douglas A. Harrison, Subba R. Palli Sep 2024

Deciphering Cellular Heterogeneity In Spodoptera Frugiperda Midgut Cell Line Through Single Cell Rna Sequencing, Surjeet Kumar Arya, Douglas A. Harrison, Subba R. Palli

Entomology Faculty Publications

Using the 10x Genomics Chromium single-cell RNA sequencing (scRNA-seq) platform, we discovered unexpected heterogeneity in an established cell line developed from the midgut of the Fall armyworm, Spodoptera frugiperda, a major global pest. We analyzed the sequences of 18,794 cells and identified ten unique cellular clusters, including stem cells, enteroblasts, enterocytes and enteroendocrine cells, characterized by the expression of specific marker genes. Additionally, these studies addressed an important knowledge gap by investigating the expression of genes coding for respiratory and midgut membrane insecticide targets classified by the Insecticide Resistance Action Committee. Dual-fluorescence tagging method, fluorescence microscopy and fluorescence- activated cell …


Hemp Regulates The Fitness Of Corn Earworm (Lepidoptera, Noctuidae) And Its Tachinid (Diptera) Parasitoids, Armando Falcon-Brindis, Raul Villanueva Sep 2024

Hemp Regulates The Fitness Of Corn Earworm (Lepidoptera, Noctuidae) And Its Tachinid (Diptera) Parasitoids, Armando Falcon-Brindis, Raul Villanueva

Entomology Faculty Publications

Pest management on hemp is still in its infancy, and biological control options are limited. Helicoverpa zea (corn earworm) is one of the key pests of hemp cultivated outdoors, especially on cultivars grown for cannabinoids and grain. In a three-year study, we assessed the effect of diet on the performance of H. zea and its tachinid parasitoids. Parasitized (bearing fly eggs) and unparasitized (without eggs) H. zea larvae were fed on hemp flowers or an artificial diet. Five tachinid species parasitized H. zea larvae, but the most abundant species were Winthemia rufopicta (68.8%) and Lespesia aletiae (28.3%). Overall, 55.2% of …


Advancements In Apoe And Dementia Research: Highlights From The 2023 Aaic Advancements: Apoe Conference., Courtney M Kloske, Michael E Belloy, Elizabeth E Blue, Gregory R Bowman, Maria C Carrillo, Xiaoying Chen, Ornit Chiba-Falek, Albert A Davis, Gilbert Di Paolo, Francesca Garretti, David Gate, Lesley R. Golden, Jay W Heinecke, Joachim Herz, Yadong Huang, Costantino Iadecola, Lance A Johnson, Takahisa Kanekiyo, Celeste M Karch, Anastasia Khvorova, Sascha J Koppes-Den Hertog, Bruce T Lamb, Paige E Lawler, Yann Le Guen, Alexandra Litvinchuk, Chia-Chen Liu, Simin Mahinrad, Edoardo Marcora, Claudia Marino, Danny M Michaelson, Justin J Miller, Josh M. Morganti, Priyanka S Narayan, Michel S Naslavsky, Marlies Oosthoek, Kapil V Ramachandran, Abhirami Ramakrishnan, Ana-Caroline Raulin, Aiko Robert, Rasha N M Saleh, Claire Sexton, Nilomi Shah, Francis Shue, Isabel J Sible, Andrea Soranno, Michael R Strickland, Julia Tcw, Manon Thierry, Li-Huei Tsai, Ryan A Tuckey, Jason D Ulrich, Rik Van Der Kant, Na Wang, Cheryl L Wellington, Stacie C Weninger, Hussein N Yassine, Na Zhao, Guojun Bu, Alison M Goate, David M Holtzman Sep 2024

Advancements In Apoe And Dementia Research: Highlights From The 2023 Aaic Advancements: Apoe Conference., Courtney M Kloske, Michael E Belloy, Elizabeth E Blue, Gregory R Bowman, Maria C Carrillo, Xiaoying Chen, Ornit Chiba-Falek, Albert A Davis, Gilbert Di Paolo, Francesca Garretti, David Gate, Lesley R. Golden, Jay W Heinecke, Joachim Herz, Yadong Huang, Costantino Iadecola, Lance A Johnson, Takahisa Kanekiyo, Celeste M Karch, Anastasia Khvorova, Sascha J Koppes-Den Hertog, Bruce T Lamb, Paige E Lawler, Yann Le Guen, Alexandra Litvinchuk, Chia-Chen Liu, Simin Mahinrad, Edoardo Marcora, Claudia Marino, Danny M Michaelson, Justin J Miller, Josh M. Morganti, Priyanka S Narayan, Michel S Naslavsky, Marlies Oosthoek, Kapil V Ramachandran, Abhirami Ramakrishnan, Ana-Caroline Raulin, Aiko Robert, Rasha N M Saleh, Claire Sexton, Nilomi Shah, Francis Shue, Isabel J Sible, Andrea Soranno, Michael R Strickland, Julia Tcw, Manon Thierry, Li-Huei Tsai, Ryan A Tuckey, Jason D Ulrich, Rik Van Der Kant, Na Wang, Cheryl L Wellington, Stacie C Weninger, Hussein N Yassine, Na Zhao, Guojun Bu, Alison M Goate, David M Holtzman

Physiology Faculty Publications

INTRODUCTION: The apolipoprotein E gene (APOE) is an established central player in the pathogenesis of Alzheimer's disease (AD), with distinct apoE isoforms exerting diverse effects. apoE influences not only amyloid-beta and tau pathologies but also lipid and energy metabolism, neuroinflammation, cerebral vascular health, and sex-dependent disease manifestations. Furthermore, ancestral background may significantly impact the link between APOE and AD, underscoring the need for more inclusive research.

METHODS: In 2023, the Alzheimer's Association convened multidisciplinary researchers at the "AAIC Advancements: APOE" conference to discuss various topics, including apoE isoforms and their roles in AD pathogenesis, progress in apoE-targeted therapeutic strategies, updates …


Novel Psychoplastogen Dm506 Reduces Cue-Induced Heroin-Seeking And Inhibits Tonic Gaba Currents In The Prelimbic Cortex, Kassandra Looschen, Shailesh N. Khatri, Malabika Maulik, Colin Salisbury, Alaina F. Carman, Katilyn Corriveau, Colton Smith, Dina Manetti, Maria Novella Romanelli, Hugo R. Arias, Cassandra D. Gipson, Swarup Mitra Sep 2024

Novel Psychoplastogen Dm506 Reduces Cue-Induced Heroin-Seeking And Inhibits Tonic Gaba Currents In The Prelimbic Cortex, Kassandra Looschen, Shailesh N. Khatri, Malabika Maulik, Colin Salisbury, Alaina F. Carman, Katilyn Corriveau, Colton Smith, Dina Manetti, Maria Novella Romanelli, Hugo R. Arias, Cassandra D. Gipson, Swarup Mitra

Markey Cancer Center Faculty Publications

Opioid use disorder is a major public health crisis that is manifested by persistent drug-seeking behavior and high relapse frequency. Most of the available treatments rely on targeting opioid receptors using small molecules that do not provide sustained symptom alleviation. Psychoplastogens are a novel class of non-opioid drugs that produce rapid and sustained effects on neuronal plasticity, intended to produce therapeutic benefits. Ibogalogs are synthetic derivatives of iboga alkaloids that lack hallucinogenic or adverse side effects. In the current study, we examine the therapeutic potential of DM506, a novel ibogalog lacking any cardiotoxic or hallucinogenic effects, in cue-induced seeking behavior …


Depressive Symptoms And Sleep Quality Mediate The Relationship Between Race And Quality Of Life Among Patients With Heart Failure: A Serial Multiple Mediator Model, Jia-Rong Wu, Debra K. Moser, Chin-Yen Lin, Ambrose A. Chiang, Barbara Riegel Sep 2024

Depressive Symptoms And Sleep Quality Mediate The Relationship Between Race And Quality Of Life Among Patients With Heart Failure: A Serial Multiple Mediator Model, Jia-Rong Wu, Debra K. Moser, Chin-Yen Lin, Ambrose A. Chiang, Barbara Riegel

UK CARES Faculty Publications

Background: Black patients with heart failure (HF) report worse quality of life (QoL) than White patients. Few investigators have examined mediators of the association between race and QoL, but depressive symptoms and sleep quality are associated with QoL.

Objective: The aim of this study was to determine whether depressive symptoms and sleep quality are mediators of the relationship between race and QoL among patients with HF.

Methods: This was a cross-sectional study. We included 271 outpatients with HF. Self-reported race (White/Black), depressive symptoms (Patient Health Questionnaire), sleep quality (Pittsburgh Sleep Quality Index), and QoL (Kansas City Cardiomyopathy Questionnaire) were collected …


Foraging Strategies Of Ruminant Livestock On Intensively Managed Grasslands: Potential And Constraints, I J. Gordon, C Lascano Aug 2024

Foraging Strategies Of Ruminant Livestock On Intensively Managed Grasslands: Potential And Constraints, I J. Gordon, C Lascano

IGC Proceedings (1977-2023)

All grazed swards exhibit heterogeneity in the spatial (horizontal and vertical) dispersion of species/biomass. A herbivore foraging at random within such a heterogeneous environment would ingest less nutrients than wou Id one which exploited the heterogeneity on offer through selective grazing. The suite of decision-making processes involved in the selective grazing we observe is termed the animal's foraging strategy. On first observation, intensively managed sown swards appear to offer little opportunity for a herbivore to exhibit a foraging strategy; however, opporlunities do exist and there is empirical evidence that herbivores foraging on sown swards tend to have a diet higher …


Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming Aug 2024

Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming

IGC Proceedings (1977-2023)

We review the evolutionary (species-specific) and ecological (individual behavioural) strategies of African grazing ungulates. The contexts considered are free-ranging wild ungulates, traditional livestock pastoralism and extensive commercial ranching. Particularly successful are (1) buffalo, able to digest grass fibre effectively in mesic grasslands; (2) wildebeest, exploiting semi-arid grasslands through migration; (3) megaherbivores (elephant, hippopotamus and white rhinoceros) utilising a wide range of vegetation components. Species-specific adaptations include body size and metabolic rate, digestive efficiency and passage rate, oral and dental anatomy, water dependence and detoxification capacity. Species overlap in grass species se'lected, with dietary differences apparent in grass height favoured, and …


Comparison Of Animal Gains Using Perennial Pastures Exclusively Or Combined With Chicory-Oats-Clover Temporary Winter Pastures, J A. Josifovich Aug 2024

Comparison Of Animal Gains Using Perennial Pastures Exclusively Or Combined With Chicory-Oats-Clover Temporary Winter Pastures, J A. Josifovich

IGC Proceedings (1977-2023)

The increment of winter forage availability using short-rotation pastures could be an interesting way to increase winter carrying capacity. The producer could make good use of higher spring grass production. Sowing oats, rye or chicory alone is quite common in the Argentine Pampa. to evaluate the efficiency of these short-rotation winter pastures a 3 year trial was carried out at Pergamino Experiment Station. The treatments were: a) perennial pastures, 100% of the surface, b) perennial pastures 75%, and chicory-clover 25%, with 2 replications of 3 ha each. The pastures were, for. class II soils, fescue (Festrlca aru11dinacea Schreb.) cv. El …


Influence Of Climatic Factors On Animal Production In The Humid Pampa Of Argentina, J D. Josifovich, E Frutos Aug 2024

Influence Of Climatic Factors On Animal Production In The Humid Pampa Of Argentina, J D. Josifovich, E Frutos

IGC Proceedings (1977-2023)

For any' pasture grazing area it is important lo know the relationship among the climatic parameters, rainfall and temperature, with carrying capacity and minimal gains. The availability of pasture to adjust stocking rates and make provisions for hay or supplementary feed needed for periods of shortage can be estimated from these data. Seven years of monthly rainfall and medium average temperature; and 25 years of forage digestibility and average daily gains were related to cattle i: carrying capacity; Analysis was made using the stepwise regression method. Carrying capacity was evaluated considering animal units (AU) for a 400 kg head gaining …


A New Theory Of Feed Intake Regulation In Ruminants And Its Implications For Forage Quality Research, J.J M.H Ketelaars, B J. Tolkamp Aug 2024

A New Theory Of Feed Intake Regulation In Ruminants And Its Implications For Forage Quality Research, J.J M.H Ketelaars, B J. Tolkamp

IGC Proceedings (1977-2023)

The low voluntary intake of many roughages is commonly explained by a limited physical capacity of ruminants to process fibrous feeds. Recently, we developed a new theory of feed intake regulation assuming feed consumption to create both benefits for the animal (represented by the intake of net energy for maintenance and gain) and costs (represented by the total oxygen consumption of the feeding animal). For non­reproducing ruminants we have shown that voluntary intake of roughages is close to the optimum feed intake level, i.e., the level at which for the animal the ratio between benefits and costs becomes maximum. According …


Botanical Composition Of Forage Samples Selected By Grazing Sheep On The Mountain Rangeland Of Northern China, Han Jianguo, Liu Fuyuan Aug 2024

Botanical Composition Of Forage Samples Selected By Grazing Sheep On The Mountain Rangeland Of Northern China, Han Jianguo, Liu Fuyuan

IGC Proceedings (1977-2023)

Oesophagus fistulae and microscopic examination were used to determine the botanical composition of forage samples selected by grazing sheep on the mountain rangeland in the Hc-Bci Province of northern China during the growing seasons of 1989 and 1990. Results show a clear preference of sheep for some forage species over others. Sheep selected Cleistogenes squarrosa, Koeleria cristata, Potentilla cihinensis, Lespedeza hedysoroides and Scabiosa comosa in each type of rangeland and from early spring to late autumn. The selection ratio of forbs was more than I , and that of grasses less than 1. Sheep showed strong preference for …


The Independent Effects Of Sward Height And Bulk Density On The Bite Parameters Of Romney Ewes And Red Deer Hinds, R J. Mitchell, J Hodgson, D A. Clark Aug 2024

The Independent Effects Of Sward Height And Bulk Density On The Bite Parameters Of Romney Ewes And Red Deer Hinds, R J. Mitchell, J Hodgson, D A. Clark

IGC Proceedings (1977-2023)

The independenl effects of sward height (I, 2, 3, 5 and 8 cm) x bulk density (0.65, 1.30, 2.90 mg DM/cm3) variation on the ingestive behaviour of Romney ewes and Red deer hinds were examined in seedling swards which simulated a leafy grass sward of low shear strength. Depth of penetration, horizontal area of herbage severed per bite, weight of each bite and the rate of intake all increased with increasing height, while the rate of biting decreased (P


Relationships Between Milk Yield, Pasture On Offer And Diet Selection In Tropical Grass Pastures, T M. Davison, W N. Orr, V J. Doogan, K Lowe Aug 2024

Relationships Between Milk Yield, Pasture On Offer And Diet Selection In Tropical Grass Pastures, T M. Davison, W N. Orr, V J. Doogan, K Lowe

IGC Proceedings (1977-2023)

A 7-year study was conducted with Holstein-Friesian cows to determine responses to different levels of nitrogen and phosphorus fertiliser applied to Gatton panic (Panicum maximum cv. Gatton) pastures. This study was used to develop relationships between milk yield, pasture and diet botanical components. Multiple regression analysis revealed there was: a negative relation between stem yield (SI) on offer in summer (S) and milk yield but a positive association with leaf yield (L) on offer in summer and green dry matter .GDM in autumn (A),, MY = 2279.0+0.529 LS-0.246 StS+0.324 GDMA _(R2 = 0.66; P


A New Ambulatory Data-Logging System For A Long Term Determination Of Grazing And Rumination Behavior On Free Ranging Cattle, Kanji Matsui, Tadakatu Okubo Aug 2024

A New Ambulatory Data-Logging System For A Long Term Determination Of Grazing And Rumination Behavior On Free Ranging Cattle, Kanji Matsui, Tadakatu Okubo

IGC Proceedings (1977-2023)

A new ambulatory apparatus (named "jaw recorder") has been developed. The apparatus has a large data storage capacity (32 768 data points), and enables data to be recorded every minute for a minimum of 22 days in one recording session. A Holstein heifer was fitted with the apparatus and was grazed with 4 other heifers for 13 days on a pasture of 0.36 ha of Italian ryegrass (Lolium nmltiflorum Lam.). Grazing and rumination period could be distinguished by a combination of jaw movements and pauses between jaw movements longer than 3 sec/min. Grazing and rumination time distinctly increased with …