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Two-Level Design Optimization Of Ac Machines With Dc Stator Excitation And Minimal Torque Ripple Using Reluctance Rotor Profile Shaping, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Torque ripple mitigation in electric machines is important for a smooth and stable operation, minimize mechanical vibrations, and enhance the overall performance. In this paper, a novel two-level optimization method is proposed for the design of synchronous flux-switching and hybrid excitation machines with an innovative multi-point spline shaping method to minimize the torque ripple. This study uses models that are validated by experimental tests from a prototype with similar topology, and exemplifies the aforementioned optimization process on a 28 pole machine. The analysis results indicate that the torque ripple can be substantially reduced with improved electromagnetic torque of the electric …

Design Of High-Power Polyphase Pcb Coil Systems For Wireless Power Transfer, Donovin D. Lewis, Lucas Gastineau, Omer Onar, Malcolm Mcculloch, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Printed circuit board (PCB) coils have been pro- posed prior for implementation as inductive wireless charging coils to minimize size and cost. Utilization of PCBs can allow for a reduced cost, improved manufacturability, and a wide range of geometric customization options. To circumvent material limitations on insulation and thermal performance, parallel paths can be implemented to divide the current per path accordingly. Within this paper, an unconventional high power PCB coil is designed employing all possible techniques for wiring with axial and radial parallel paths with equivalent transposition to minimize circulating currents. Design studies are simulated in 3D finite element …

Model Predictive Control Of 5l-Anpc Inverter Fed Coreless Afpm Motor With Mitigated Cmv In Electric Aircraft Propulsion, Farzad Y. Notash, Matin Vatani, Jiangbiao He, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper proposes a fast model predictive control (FMPC) method without weighting factors and mitigated common-mode voltage (CMV) for a five-level active neutral point clamped (5L-ANPC) inverter-fed electric aircraft propulsion system with a coreless axial flux permanent magnet (CAFPM) motor. This motor is specifically designed for electric aircraft propulsion through a combined electromagnetic and thermal evaluation, benefiting from a high specific power density, efficiency, and integrated thermal management system. The proposed method utilizes the deadbeat approach to calculate the reference voltage vector and compensate for the one-time interval delay between the predicted and applied switching commands. The angle and amplitude …

Analytical And Fe Modeling For The Design Of Coreless Axial Flux Machines With Halbach Array And Surface Pm Rotors, Matin Vatani, Yaser Chulaee, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper introduces a rapid analytical modeling approach for coreless axial flux permanent magnet (AFPM) machines featuring surface-mounted and Halbach PM array rotors. The methodology employs a 2D model at an arbitrary diameter of the machine and converts AFPM machines into an equivalent linear machine. Initially, equations for PM flux density, accounting for harmonic content, are developed for both rotor types. Subsequently, a force equation is derived for the 2D equivalent machine based on the Lorentz force equation and the stator winding factor. In the final step, a torque equation at an arbitrary diameter—specifically, the average diameter in this paper—is …

Multi-Disk Coreless Axial Flux Permanent Magnet Synchronous Motors With Surface Pm And Halbach Array Rotors For Electric Aircraft Propulsion, Matin Vatani, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents multiple single- and multi-disk coreless axial flux permanent magnet (AFPM) motors, focusing on specific power density and reliability for electric aircraft propulsion. Several 3D finite element analysis (FEA) parametric studies were conducted to assess the geometric impacts on a single-disk coreless AFPM motor featuring two separate stators and a double-sided Halbach array rotor configuration. These studies form the foundation for the design of both single and multi-disk machines. Single-disk coreless AFPM motors with rotor back iron embedded between the stators, offering magnetically decoupled stators, are subsequently introduced. The paper concludes by presenting four multi-disk coreless AFPM motor …

Multi-Wound Axial Flux Generators With Halbach Array Rotors, Matin Vatani, Yaser Chulaee, John F. Eastham, Xiaoze Pei, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents three coreless axial flux permanent magnet (AFPM) generator topologies that feature magnetically and electrically decoupled outputs using a single prime mover. The proposed topologies include: (1) two separate generators mounted on the same shaft, (2) a nested configuration with a smaller generator inside a larger one, and (3) a multi-wound generator with two sets of windings and different pole numbers for each rotor side. The multi-wound generator is selected for further investigation due to its superior power-to-volume ratio and the advantage of utilizing a single structure for stator cooling. The airgap magnetic flux density equation is derived …

The Undergraduate Engineering Mental Health Help-Seeking Instrument (Ue-Mh-Hsi): Development And Validity Evidence, Joseph H. Hammer, Courtney J. Wright, Melanie E. Miller, Sarah A. Wilson

Chemical and Materials Engineering Faculty Publications

Background: Undergraduate engineering students experiencing distress are less likely than peers to ask for professional help. A population-specific instrument to facilitate the identification of factors that influence mental healthcare utilization could guide development and testing of interventions to increase help seeking.

Purpose: We used mixed methods guided by the Integrated Behavioral Model (IBM) to develop and evaluate the Undergraduate Engineering Mental Health Help-Seeking Instrument (UE-MH-HSI).

Method: First, we adapted existing measures of mental health help-seeking intention and mechanisms (i.e., attitudes, perceived norm: injunctive, perceived norm: descriptive, personal agency: autonomy, personal agency: capacity). Second, we coded qualitative interviews (N = 33) …

Impact Of Maternal Moringa Oleifera Leaf Supplementation On Milk And Serum Vitamin A And Carotenoid Concentrations In A Cohort Of Breastfeeding Kenyan Women And Their Infants, Suzanna Labib Attia, Silvia A. Odhiambo, Jerusha N. Mogaka, Raphael Ondondo, Aric Schadler, Kristen Mcquerry, George J. Fuchs, Janet E. Williams, Michelle K. Mcguire, Carrie Waterman, Kerry Schulze, Patrick M. Owuor

Biostatistics Faculty Publications

Background: Childhood vitamin A deficiency leads to increased morbidity and mortality. Human milk is the only source of vitamin A for exclusively breastfed infants. Dried Moringa oleifera leaf powder (moringa) is a good food source of provitamin A and other carotenoids. Its effect during lactation on human milk vitamin A and carotenoid content is unclear. Objectives: Our objective was to investigate the effect of maternal moringa consumption on human milk retinol and carotenoid concentrations and maternal and infant vitamin A status. Methods: We conducted a 3-month pilot single-blinded cluster-randomized controlled trial in breastfeeding mother–infant pairs (n = 50) in Kenya. …

A Small Molecule P38Α Mapk Inhibitor, Mw150, Attenuates Behavioral Deficits And Neuronal Dysfunction In A Mouse Model Of Mixed Amyloid And Vascular Pathologies, Hilaree N. Frazier, David J. Braun, Caleb S. Bailey, Meggie J. Coleman, Verda A. Davis, Stephen R. Dundon, Christopher J. Mclouth, Hana C. Muzyk, David K. Powell, Colin B. Rogers, Saktimayee M. Roy, Linda J. Van Eldik

Biostatistics Faculty Publications

Background: Inhibition of p38 alpha mitogen activated protein kinase (p38α) has shown great promise as a treatment for Alzheimer's disease (AD) in preclinical tests. However, previous preclinical studies were performed in “pure” models of AD pathology. A vast majority of AD patients have comorbid dementia-contributing pathologies, particularly some form of vascular damage. The present study therefore aimed to test the potential of p38α inhibition to address dysfunction in the context of comorbid amyloid and vascular pathologies. Methods: An amyloid overexpressing mouse strain (5xFAD) was placed on an 8-week long diet to induce the hyperhomocysteinemia (HHcy) model of small vessel disease. …

Bacillus Thuringiensis Cry14a Family Proteins As Novel Anthelmintics Against Gastrointestinal Nematode Parasites, Duy Hoang, Kelly Flanagan, Qian Ding, Nicholas R. Cazeault, Hanchen Li, Stefani Díaz-Valerio, Florentina Rus, Esther A. Darfour, Elizabeth Kass, Katherine H. Petersson, Martin Krarup Nielsen, Heiko Liesegang, Gary R. Ostroff, Raffi V. Aroian

Veterinary Science Faculty Publications

Bacillus thuringiensis crystal (Cry) proteins have been expressed in commercial transgenic crops for nearly 30 years, providing safe and effective control of insect pests and significantly reducing the application of hazardous chemical pesticides. B. thuringiensis crystal proteins have also been shown to target parasitic nematodes, including plant parasitic nematodes. Recently, transgenic soybean crops expressing Cry14Ab have been shown to provide control against the soybean cyst nematode Heterodera glycines, marking the first time a crystal protein is being commercialized in transgenic crops for control of a nematode pest. However, apart from H. glycines and the free-living nematode, Caenorhabditis elegans, the breadth …

Arthropod Arbiters: Natural Enemy Communities Mediate The Effects Of Landscape And Local-Scale Complexity On Lygus-Induced Crop Loss In Organic Strawberries, Adrian Lu, David J. Gonthier, Amber Sciligo, Karina Garcia, Taiki Chiba, Gila Juárez, Claire Kremen

Entomology Faculty Publications

Sustainable pest management requires growers and regional land managers to consider the relationships among pest management practices, pest and natural enemy communities, crop loss, and multi-scalar habitat complexity. However, the causal links among these variables, in particular potential interactions between landscape and local-scale habitat complexity, remain underexplored. In the context of organically managed strawberry crops in California’s Central Coast, we tested the independent effects of landscape and local habitat complexity gradients on arthropod communities and crop loss using a piecewise structural equation model (PSEM). We found that landscape-scale woody habitat proportion indirectly decreased crop loss through its positive effect on …

Communities That Heal Intervention And Mortality Including Polysubstance Overdose Deaths: A Randomized Clinical Trial, Bridget Freisthler, Rouba A. Chahine, Jennifer Villani, Redonna Chandler, Daniel J. Feaster, Svetla Slavova, Jolene Defiore-Hyrmer, Alexander Y. Walley, Sarah Kosakowski, Arnie Aldridge, Carolina Barbosa, Sabana Bhatta, Candace Brancato, Carly Bridden, Mia Christopher, Tom Clarke, James David, Lauren D'Costa, Irene Ewing, Soledad Fernandez, Erin Gibson, Louisa Gilbert, Megan E. Hall, Sarah Hargrove, Timothy Hunt, Elizabeth N. Kinnard, Lauren Larochelle, Aaron Macoubray, Shawn R. Nigam, Edward V. Nunes, Carrie B. Oser, Sharon Pagnano, Peter J. Rock, Pamela Salsberry, Aimee Shadwick, Thomas J. Stopka, Sylvia Tan, Jessica L. Taylor, Philip M. Westgate, Elwin Wu, Gary A. Zarkin, Sharon L. Walsh, Nabila El-Bassel, T. John Winhusen, Jeffrey H. Samet, Emmanuel A. Oga

Biostatistics Faculty Publications

IMPORTANCE: The HEALing Communities Study (HCS) evaluated the effectiveness of the Communities That HEAL (CTH) intervention in preventing fatal overdoses amidst the US opioid epidemic.

OBJECTIVE: To evaluate the impact of the CTH intervention on total drug overdose deaths and overdose deaths involving combinations of opioids with psychostimulants or benzodiazepines.

DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial was a parallel-arm, multisite, community-randomized, open, and waitlisted controlled comparison trial of communities in 4 US states between 2020 and 2023. Eligible communities were those reporting high opioid overdose fatality rates in Kentucky, Massachusetts, New York, and Ohio. Covariate constrained randomization stratified …

Cerebrovascular Disease Is Associated With Alzheimer's Plasma Biomarker Concentrations In Adults With Down Syndrome, Andreas Engvig, Karl Trygve Kalleberg, Lars T. Westlye, Esten Høyland Leonardsen, Alzheimer’S Disease Neuroimaging Initiative Consortium

Neurology Faculty Publications

DNA methylation age (MA), brain age (BA), and frailty index (FI) are putative aging biomarkers linked to dementia risk. We investigated their relationship and combined potential for prediction of cognitive impairment and future dementia risk using the ADNI database. Of several MA algorithms, DunedinPACE and GrimAge2, associated with memory, were combined in a composite MA alongside BA and a data-driven FI in predictive analyses. Pairwise correlations between age- and sex-adjusted measures for MA (aMA), aBA, and aFI were low. FI outperformed BA and MA in all diagnostic tasks. A model including age, sex, and aFI achieved an area under the …

Integrin Α6Β4 Upregulates Ptprz1 Through Uchl1-Mediated Hif-1Α Nuclear Accumulation To Promote Triple-Negative Breast Cancer Cell Invasive Properties, Min Chen, Parvanee A. Karimpour, Andrew Elliott, Daheng He, Teresa Knifley, Jinpeng Liu, Chi Wang, Kathleen L. O’Connor

Markey Cancer Center Faculty Publications

Integrin α6β4 drives triple-negative breast cancer (TNBC) aggressiveness through the transcriptional regulation of key genes. Here, we investigated how integrin α6β4 regulates protein tyrosine phosphatase receptor type Z1 (PTPRZ1). Using stable re-expression of integrin β4 (ITGB4) in cells naturally devoid of integrin α6β4 or knockdown or knockout (KO) of ITGB4, we found that integrin α6β4 regulates PTPRZ1 expression. To gain mechanistic insight, we focused on Hif-1α due to the impact of integrin α6β4 on a hypoxia-associated signature. We found that nuclear localization of Hif-1α, but not Hif-2α, was substantially enhanced with integrin α6β4 signaling. Hif-1α knockdown by shRNA or chemical …

Knockdown Of Ketohexokinase Versus Inhibition Of Its Kinase Activity Exert Divergent Effects On Fructose Metabolism, Se-Hyung Park, Taghreed Fadhul, Lindsey R. Conroy, Harrison A. Clarke, Ramon Sun, Kristina Wallenius, Jeremie Boucher, Gavin O'Mahony, Alessandro Boianelli, Marie Persson, Sunhee Jung, Cholsoon Jang, Analia S. Loria, Genesee J. Martinez, Zachary A. Kipp, Evelyn A. Bates, Terry D. Hinds Jr., Senad Divanovic, Samir Softic

Markey Cancer Center Faculty Publications

Excessive fructose intake is a risk factor for the development of obesity and its complications. Targeting ketohexokinase (KHK), the first enzyme of fructose metabolism, has been investigated for the management of metabolic dysfunction–associated steatotic liver disease (MASLD). We compared the effects of systemic, small molecule inhibitor of KHK enzymatic activity with hepatocyte-specific, N-acetylgalactosamine siRNA–mediated knockdown of KHK in mice on an HFD. We measured KHK enzymatic activity, extensively quantified glycogen accumulation, performed RNA-Seq analysis, and enumerated hepatic metabolites using mass spectrometry. Both KHK siRNA and KHK inhibitor led to an improvement in liver steatosis; however, via substantially different mechanisms, KHK …

Cost-Effectiveness Of Point Of Care Smoking Cessation Interventions In Oncology Clinics., Kerri A. Mullen, Kelly Hurley, Shelley Hewitson, Joshua Scoville, Alyssa Grant, Kednapa Thavorn, Eshwar Kumar, Graham W. Warren

Markey Cancer Center Faculty Publications

BACKGROUND: We examined the cost-effectiveness of providing systematic smoking cessation interventions to oncology patients at point-of-care.

METHODS: A decision analytic model was completed from the healthcare payer's perspective and included all incident cancer cases involving patients who smoke in New Brunswick, Canada (n = 1040), cancer site stratifications, and risks of mortality, continued smoking, and cancer treatment failure over one year. Usual care (no cessation support) was compared to the standard Ottawa Model for Smoking Cessation (OMSC) intervention, and to OMSC plus unlimited cost-free stop smoking medication (OMSC + SSM), including nicotine replacement therapy, varenicline, or bupropion. Primary outcomes were …

Predicting The Pathway Involvement Of All Pathway And Associated Compound Entries Defined In The Kyoto Encyclopedia Of Genes And Genomes, Erik D. Huckvale, Hunter Moseley

Markey Cancer Center Faculty Publications

Background/Objectives: Predicting the biochemical pathway involvement of a compound could facilitate the interpretation of biological and biomedical research. Prior prediction approaches have largely focused on metabolism, training machine learning models to solely predict based on metabolic pathways. However, there are many other types of pathways in cells and organisms that are of interest to biologists. Methods: While several publications have made use of the metabolites and metabolic pathways available in the Kyoto Encyclopedia of Genes and Genomes (KEGG), we downloaded all the compound entries with pathway annotations available in the KEGG. From these data, we constructed a dataset where each …

Upregulation Of Fatty Acid Synthase Increases Activity Of Β-Catenin And Expression Of Notum To Enhance Stem-Like Properties Of Colorectal Cancer Cells, Courtney O. Kelson, Josiane Weber Tessmann, Mariah E. Geisen, Daheng He, Chi Wang, Tianyan Gao, B. Mark Evers, Yekaterina Y. Zaytseva

Markey Cancer Center Faculty Publications

Dysregulated fatty acid metabolism is an attractive therapeutic target for colorectal cancer (CRC). We previously reported that fatty acid synthase (FASN), a key enzyme of de novo synthesis, promotes the initiation and progression of CRC. However, the mechanisms of how upregulation of FASN promotes the initiation and progression of CRC are not completely understood. Here, using Apc/VillinCre and ApcMin mouse models, we show that upregulation of FASN is associated with an increase in activity of β-catenin and expression of multiple stem cell markers, including Notum. Genetic and pharmacological downregulation of FASN in mouse adenoma organoids decreases the activation of β-catenin …

The Absence Of Cxcl10 Activity Does Not Affect The Capability Of Cd8+ T Cells To Migrate And Eliminate The Tissue Cysts Of Toxoplasma Gondii From The Brains Of Chronically Infected Mice, Rajesh Mani, Yasuhiro Suzuki

Markey Cancer Center Faculty Publications

Toxoplasma gondii forms tissue cysts in neurons and astrocytes in the brain to establish chronic infection, and astrocytes express the CXCL10 chemokine in chronically infected mice. Since chemokines mediate the migration of T cells to attack their targets, and since CXCL10 plays key roles in T cell-mediated control of the proliferation of tachyzoites (the acute stage form) of T. gondii during the acute stage of infection, we examined whether CXCL10 is involved in recruiting anti-cyst CD8+ cytotoxic T cells to eliminate the cysts in their brains. We employed adoptive transfer of CD8+ immune T cells to infected, T cell-deficient SCID …

The Impact Of Pdcd4, A Translation Inhibitor, On Drug Resistance, Qing Wang, Hsin-Sheng Yang

Markey Cancer Center Faculty Publications

Programmed cell death 4 (Pdcd4) is a tumor suppressor, which has been demonstrated to efficiently suppress tumorigenesis. Biochemically, Pdcd4 binds with translation initiation factor 4A and represses protein translation. Beyond its role in tumor suppression, growing evidence suggests that Pdcd4 enhances the chemosensitivity of several anticancer drugs. To date, numerous translational targets of Pdcd4 have been identified. These targets govern important signal transduction pathways, and their attenuation may improve chemosensitivity or overcome drug resistance. This review will discuss the signal transduction pathways regulated by Pdcd4 and the potential mechanisms through which Pdcd4 enhances chemosensitivity or counteracts drug resistance.

Environmental Conditions Influencing Seasonal Population Dynamics Of Drosophila Suzukii (Diptera: Drosophilidae) In A Mid-Latitude Organic Farm Data, Eleanor Mccabe, Nicholas M. Teets, Jack J. Devlin, Megan E. Mccabe

Entomology Research Data

1. The local population dynamics of an invasive species are important for predicting impacts and determining proper management approaches. Temporal and spatial distribution can influence monitoring and treatment decisions and understanding climatic variables that affect population size can help predict peak population numbers.
2. Drosophila suzukii (Matsumara, 1931) is an invasive fruit pest, and its seasonal dynamics vary across its range. In this study, we conducted a three-year trapping study in conjunction with various modeling approaches to determine the environmental variables that influence population dynamics of D. suzukii across all seasons in central Kentucky.
3. Both male and female flies …

2024 Kentucky Water Resources Annual Symposium, Kentucky Water Research Institute

Kentucky Water Resources Annual Symposium

The program and proceedings contains details of the 2024 Kentucky Water Resources Symposium, including presentations, award winners, and poster presentations.

This symposium was planned and conducted as a part of the state water resources research institute annual program that is supported by Grant/Cooperative Agreement Number G21AP10631-02 from the United States Geological Survey (USGS). The contents of this proceedings document and the views and conclusions presented at the symposium are solely the responsibility of the individual authors and presenters and do not represent the official views of the USGS or of the symposium organizers and sponsors. This publication is produced with …

2024 Kentucky Water Resources Annual Symposium, Kentucky Water Research Institute

Kentucky Water Resources Annual Symposium

No abstract provided.

Book Review: Welcome The Wretched: In Defense Of The "Criminal Alien", Matthew Boaz

Law Faculty Popular Media

Prof. César Cuauhtémoc García Hernández has spent more than a decade writing about the intersection of criminal law and immigration law. In his most recent book, Welcome the Wretched: In Defense of the “Criminal Alien,” he offers a bold proclamation – that immigration enforcement in the United States should be untethered from the criminal legal system. Grounding his argument are two equally important assertions: (1) tying deportation to perceived criminal activity does not make the United States any safer, and (2) migrants are people, “complicated and contradictory,” but worthy of consideration beyond their greatest missteps.

Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath

IGC Proceedings (1977-2023)

Level of nnimal production from grassland is determined by the amount of pasture grown, pasture utilisation and animal conversion efficiency. The key components affecting production are pasture growth and animal conversion efficiency. These arc mainly influenced by environment, genetics and through inputs to maintain soil fertility or animal health. Systems development aims to link pasture growth and animal conversion through efficient strategies for pasture utilisation. The means of influencing pasture utilisation is through adjustments to animal feed demand, feed supply or grazing management. Stock policies that adjust the pattern and level of feed demand are of greatest significance in developing …

The Ecology Of Grazing Management, R K. Heitschmidt

IGC Proceedings (1977-2023)

The broad objective of this paper is to review the fundamental principles of grazing management as a means of assessing the inherent value of intensive and extensive grazing systems. Conceptual analyses of intensive and extensive grazing systems reveal that the fundamental differences between intensive and extensive grazing systems are related to differences in non-grazing rather than grazing tactics. Intensive grazing systems employ a wide array of non-grazing tactics in an attempt to overcome the inherent ecological constraints that limit secondary (i.e., livestock) productivity in extensively grazed systems. Moreover, analyses of the ecological or true efficiency of various agricultural production systems …

An Analysis Of The Dry Matter Intake And Rate Of Live-Weight Gain Of Growing Cattle Fed Forage Diets, J G. Buchanan-Smith

IGC Proceedings (1977-2023)

The intake and rate of live-weight gain of 500 growing steer calves fed experimental forage diets in 7 trials were compared with corresponding values predicted using the Na1ional Research Council (NRC) model (1984). The cattle were predominantly weaned calves and most of the experimental diets were alfalfa-grass silage, either unsupplemented or supplemented with various protein sources, but some diets were based on maize silage or maize grain. The feeding period evaluated in this study ranged between the first 84 and 147 days when protein accretion rate in the cattle would be relatively high. Dry matter intakes were overpredicted by the …

Management Of Extensive Pastures For Dairy Youngstock, G.E J. Fisher, D J. Roberts

IGC Proceedings (1977-2023)

The effects of low input systems on the ground cover of species and yield and chemical composition of herbage cul from extensive lowland swards was studied over 3 years. The live-weight gain of dairy heifer replacements offered grazed or conserved forage from these pastures was also assessed, The swards were sown with a mixture of grasses, wildflowers and herbs and received no inorganic fertilizers, Applications of slurry in January and February increased herbage yield by 43%, but reduced the cover of flowers and herbs. Using a 2- cut conservation system improved yield of metabolisable energy/ha in herbage by 33%, and …

Intensive Grazing Of Alfalfa By Beef Steers, M Rasnake, W R. Burris, G D. Lacefield, J Randolph, N Gay, L Davis

IGC Proceedings (1977-2023)

In the temperate region of North America, high temperature and moisture deficit cause low forage growth during the summer of most years, making it difficult to grow beef (Bos taurus), calves through summer grazing. Alfalfa (Medicago sativa), offers some potential to provide high dry matter production during summer if an effective system of grazing can be developed. The objective of this study was to test a system of intensive grazing of beef steers on alfalfa to maximise live-weight gains/ha and maintain plant population. Alfalfa was no-till seeded into a 6.5 ha field in autumn 1988 after …

Variance Across Years In Growth Of Cattle On Annual Pastures In A Mediterranean Climate, K D. Greathead, J Zorrilla Rios

IGC Proceedings (1977-2023)

Annual pastures were continuously grazed by new drafts of yearling cattle each year for 4 years at 2 sites. The variability of weight gained across years at any date was not different between sites. The level of rainfall in April, but strongly influenced weight gained by the cattle in any year. Variances in weight change were small up to April, they increased rapidly from April to late July and were not different after July (P<0.05).