Digital Commons Network^™

Paradox Lost: Wide Gape In The Ordovician Brachiopod Rafinesquina Explains How Unattached Filter-Feeding Strophomenoids Thrived On Muddy Substrates, Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn

Earth and Environmental Sciences Faculty Publications

Strophomenoid brachiopods had thin, concavo-convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter-fed in a concave-upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore-clogging mud. The paradox is that epi- biont distributions on strophomenoids support a convex-upward life position, as do studies of strophome- noid stability and trace fossils formed by strophomenoid sediment-clearing. A premise of the concave-upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vul- nerable to sediment entrainment. Herein we investigate the gape angle of Rafinesquina using serial …

Joint Environmental And Social Benefits From Diversified Agriculture, Laura Vang Rasmussen, Ingo Grass

Earth and Environmental Sciences Faculty Publications

Agricultural simplification continues to expand at the expense of more diverse forms of agriculture. This simplification, for example, in the form of intensively managed monocultures, poses a risk to keeping the world within safe and just Earth system boundaries. Here, we estimated how agricultural diversification simultaneously affects social and environmental outcomes. Drawing from 24 studies in 11 countries across 2655 farms, we show how five diversification strategies focusing on livestock, crops, soils, noncrop plantings, and water conservation benefit social (e.g., human well-being, yields, and food security) and environmental (e.g., biodiversity, ecosystem services, and reduced environmental externalities) outcomes. We found that …

Guidebook For Project Management, Jill Asher, Keith Caudill, Travis Thompson, Jeff Jasper, Chris Van Dyke, Samantha Wright, Bryan Gibson, Pam Clay-Young, Candice Wallace

Kentucky Transportation Center Research Report

For the Kentucky Transportation Cabinet’s (KYTC) Department of Highways, project development encompasses all the work activities needed to move a transportation project from concept and project initiation to construction letting. Developing projects efficiently requires the adoption of sound project management practices. Although KYTC has a long track record of executing complex projects, doing so is increasingly challenging due to staff attrition and the attendant loss of institutional knowledge. Today’s entry- and mid-level project managers have more responsibilities than ever but lack a trusted source of guidance to help them manage projects from development through completion. The objective of this study …

Reducing Vehicle Licensing And Titling Fraud, Mallory Brown, Andrew Martin, Jeeyen Koo, Jennifer Walton

Kentucky Transportation Center Research Report

This study reviews Kentucky’s vehicle licensing and registration program, evaluates methods of motor vehicle title fraud, examines current anti-fraud mechanisms in Kentucky, reports on vehicle titling and anti-fraud efforts in other states, assesses Ohio’s vehicle inspection program, and develops a proposal for a new Kentucky rebuilt title inspection program. Researchers developed the proposal based on historical Kentucky vehicle registration and titling data, a survey of other states, and other information provided by Kentucky’s Division of Motor Vehicle Licensing and other agency partners. Kentucky historical data revealed consistently high numbers of salvage title applications as well as spatial concentration in rebuilt …

A Multi-Ancestry Genetic Study Of Pain Intensity In 598,339 Veterans., Sylvanus Toikumo, Rachel Vickers-Smith, Zeal Jinwala, Heng Xu, Divya Saini, Emily E Hartwell, Mirko Pavicic, Kyle A Sullivan, Ke Xu, Daniel A Jacobson, Joel Gelernter, Christopher T Rentsch, Million Veteran Program, Eli Stahl, Martin Cheatle, Hang Zhou, Stephen G Waxman, Amy C Justice, Rachel L Kember, Henry R Kranzler

Epidemiology and Environmental Health Faculty Publications

Chronic pain is a common problem, with more than one-fifth of adult Americans reporting pain daily or on most days. It adversely affects the quality of life and imposes substantial personal and economic costs. Efforts to treat chronic pain using opioids had a central role in precipitating the opioid crisis. Despite an estimated heritability of 25-50%, the genetic architecture of chronic pain is not well-characterized, in part because studies have largely been limited to samples of European ancestry. To help address this knowledge gap, we conducted a cross-ancestry meta-analysis of pain intensity in 598,339 participants in the Million Veteran Program, …

Barriers To Opioid Use Disorder Treatment Among People Who Use Drugs In The Rural United States: A Qualitative, Multi-Site Study., T. J. Stopka, A. T. Estadt, G. Leichtling, J. C. Schleicher, L. S. Mixson, J. Bresett, E. Romo, P. Dowd, S. M. Walters, A. M. Young, W. Zule, P. D. Friedmann, V. F. Go, R. Baker, R. J. Fredericksen

Epidemiology and Environmental Health Faculty Publications

BACKGROUND: In 2020, 2.8 million people required substance use disorder (SUD) treatment in nonmetropolitan or 'rural' areas in the U.S. Among this population, only 10% received SUD treatment from a specialty facility, and 1 in 500 received medication for opioid use disorder (MOUD). We explored the context surrounding barriers to SUD treatment in the rural United States.

METHODS: We conducted semi-structured, in-depth interviews from 2018 to 2019 to assess barriers to SUD treatment among people who use drugs (PWUD) across seven rural U.S. study sites. Using the social-ecological model (SEM), we examined individual, interpersonal, organizational, community, and policy factors contributing …

Interaction Between Continuous Pack-Years Smoked And Polygenic Risk Score On Lung Cancer Risk, Meredith S. Duncan, Hector Diaz-Zabala, James Jaworski, Hilary A. Tindle, Robert A. Greevy, Loren Lipworth, Rayjean J. Hung, Matthew S. Freiberg, Melinda C. Aldrich

Biostatistics Faculty Publications

Background: Lung cancer risk attributable to smoking is dose dependent, yet few studies examining a polygenic risk score (PRS) by smoking interaction have included comprehensive lifetime packyears smoked. Methods: We analyzed data from participants of European ancestry in the Framingham Heart StudyOriginal (n = 454) andOffspring (n = 2,470) cohorts enrolled in 1954 and 1971, respectively, and followed through 2018. We built a PRS for lung cancer using participant genotyping data and genome-wide association study summary statistics froma recent study in theOncoArray Consortium. We used Cox proportional hazards regression models to assess risk and the interaction between pack-years smoked and …

Genetic Associations With Dementia-Related Proteinopathy, Yuriko Katsumata, David W. Fardo, Lincoln M.P. Shade, Xian Wu, Shama D. Karanth, Timothy J. Hohman, Julie A. Schneider, David A. Bennett, Jose M. Farfel, Kathryn Gauthreaux, Charles Mock, Walter A. Kukull, Erin L. Abner, Peter T. Nelson, Maria Carrillo, Eric M. Reiman, Kewei Chen, Donna Masterman, Robert C. Green, Carole Ho, Adam Fleisher, Andrew J. Saykin, Kwangsik Nho, Liana G. Apostolova, Shannon L. Risacher, Jonathan Jackson

Biostatistics Faculty Publications

INTRODUCTION: Although dementia-related proteinopathy has a strong negative impact on public health, and is highly heritable, understanding of the related genetic architecture is incomplete. METHODS: We applied multidimensional generalized partial credit modeling (GPCM) to test genetic associations with dementia-related proteinopathies. Data were analyzed to identify candidate single nucleotide variants for the following proteinopathies: Aβ, tau, α-synuclein, and TDP-43. RESULTS: Final included data comprised 966 participants with neuropathologic and WGS data. Three continuous latent outcomes were constructed, corresponding to TDP-43-, Aβ/Tau-, and α-synuclein-related neuropathology endophenotype scores. This approach helped validate known genotype/phenotype associations: for example, TMEM106B and GRN were risk alleles …

Neurological Diagnoses In Hospitalized Covid-19 Patients Associated With Adverse Outcomes, Meghan R Hutch, Jiyeon Son, Trang T Le, Chuan Hong, Xuan Wang, Zahra Shakeri Hossein Abad, Michele Morris, Alba Gutiérrez-Sacristán, Jeffrey G Klann, Anastasia Spiridou, Ashley Batugo, Riccardo Bellazzi, Vincent Benoit, Clara-Lea Bonzel, William A Bryant, Lorenzo Chiudinelli, Kelly Cho, Priyam Das, Tomás González González, David A Hanauer, Darren W Henderson, Yuk-Lam Ho, Ne Hooi Will Loh, Adeline Makoudjou, Simran Makwana, Alberto Malovini, Bertrand Moal

Biostatistics Faculty Publications

Few studies examining the patient outcomes of concurrent neurological manifestations during acute COVID-19 leveraged multinational cohorts of adults and children or distinguished between central and peripheral nervous system (CNS vs. PNS) involvement. Using a federated multinational network in which local clinicians and informatics experts curated the electronic health records data, we evaluated the risk of prolonged hospitalization and mortality in hospitalized COVID-19 patients from 21 healthcare systems across 7 countries. For adults, we used a federated learning approach whereby we ran Cox proportional hazard models locally at each healthcare system and performed a meta-analysis on the aggregated results to estimate …

New Voices For A Better Society, Stephanie J. Diem, Baindu L. Bayon, Hussam Mahmoud, Mary L. Garcia- Cazarin, Michael J. Martin, Clare C. Rittschof, Patricia Silveyra, Umut A. Gurkan, Alison Boland- Reeves, Dalal Najib, Flannery Wasson

Entomology Faculty Publications

No abstract provided.

Antioxidant Properties Of Bovine Liver Protein Hydrolysates And Their Practical Application In Biphasic Systems, Betul Arslan, Youling L. Xiong, Ayla Soyer

Animal and Food Sciences Faculty Publications

BACKGROUND: The influence of protein hydrolysate produced from bovine liver protein hydrolysate (LPH) by enzymatic hydrolysis, using Alcalase/Protamex (1:1), on lipid dispersions was investigated. LPH production was optimized to maximize the antioxidant activity (at 45, 50, and 55 °C for 12, 18, and 24 h). Different concentrations of LPHs (1, 3, and 5 mg/g) were added to emulsions and to liposomes. Lipid oxidation level and particle size of the lipid dispersions were monitored for 14 days of storage at 25 °C. RESULTS: Radical scavenging activity and reducing power were the highest at 45 °C after 24 h of hydrolysis. Electrophoresis …

Foraging Behaviour Of Heifers, Sheep And Goats In Grass-Legume Cafeteria, J P. Singh, Vinod Shankar, V S. Upadhyay

IGC Proceedings (1977-2023)

The paper reports findings of a grazing trial with heifers, sheep and goats in a grass–legume cafeteria involving 45x10 m alternate strips of 18 grasses and 18 legumes. In the first year heifers were grazed. Sheep were introduced in the second year and goats in the third year. The stocking rate was 1.5 ACU/ha. Foraging behaviour of three kinds of animals differed in many respects with grazing and rest durations, choice of species in the forenoon and afternoon and in different seasons. Heifers, by and large, preferred grasses over legumes and browse. Sheep, on the contrary, preferred legumes over grasses …

Intake And Diet Selection By Sheep Grazing Grass/Clover Patches, I J. Gordon, A W. Illius

IGC Proceedings (1977-2023)

The effects of the spatial dispersion of ryegrass (Lolium perenne L) and clover (Trifolium repens L), at the feeding station scale, on diet composition and feeding behaviour were studied for sheep. There were no significant changes in diet composition with changes in the spatial dispersion of sward components. Bite size, bite rate and intake rate did increase as the species became more aggregated.

Western Science And Eastern Zen To Seek The Origin Of Truth: Philosophical Background Of Scale Modeling, Kozo Saito

Progress in Scale Modeling, an International Journal

This article was written to introduce philosophical background of scale modeling, where Zen philosophy was applied to overcome the limitation of logical thinking and hypotheses-driven deductive science. Three specific reasons are as follows. The first is related to the law approach in scale modeling; it uses the kufu principle, originated in Zen Buddhism, together with the other three scientific methods: experimental, theoretical, and computational. The second reason is because scale modeling seeks relativistic understanding by attempting to realize similarity; the concept is closer to Eastern philosophy rather than absolute understanding cultivated by deductive science. The third is in the educational …

Online Instructional Tools For Motor Carriers, Brian Howell, Jennifer Walton, Paul Ross, Andrew Martin

Kentucky Transportation Center Research Report

Commercial motor carrier customers on Kentucky highways must register and pay taxes for licensing and credentialing requirements. The Kentucky Transportation Cabinet (KYTC) provides an online Motor Carrier Portal that offers information and instructions on meeting these requirements, but customers have increasingly resorted to calling into KYTC’s motor carrier help desk, thereby straining limited personnel resources. The Kentucky Transportation Center (KTC) coordinated with KYTC to develop a series of online instructional videos that can better assist customers with applying for and meeting credentialing requirements.

KTC researchers used a three-phase approach to determine the feasibility and requirements for instructional videos. First, they …

Older Adults Using Social Support To Improve Self-Care (Oasis), Brittany L. Smalls, Aaron Kruse-Diehr, Courtney L. Ortz, Key Douthitt, Christopher Mclouth, Rachel Shelton, Zoe Taylor, Edith Williams

Biostatistics Faculty Publications

Introduction The prevalence of type 2 diabetes (T2D) is 17% higher in rural dwellers compared to their urban counterparts, and it increases with age, with an estimated 25% of older adults (≥ 65 years) diagnosed. Appropriate self-care is necessary for optimal clinical outcomes. Overall, T2D self-care is consistently poor among the general population but is even worse in rural-dwellers and older adults. In rural Kentucky, up to 23% of adults in Appalachian communities have been diagnosed with T2D and, of those, 26.8% are older adults. To attain optimal clinical outcomes, social environmental factors, including social support, are vital when promoting …

Quantitative Foveal Structural Metrics As Predictors Of Visual Acuity In Human Albinism, Erica N. Woertz, Gelique D. Ayala, Niamh Wynne, Sergey Tarima, Serena Zacharias, Murray H. Brilliant, Taylor M. Dunn, Deborah Costakos, C. Gail Summers, Sasha Strul, Arlene V. Drack, Joseph Carroll

Biostatistics Faculty Publications

PURPOSE. To assess the degree to which quantitative foveal structural measurements account for variation in best-corrected visual acuity (BCVA) in human albinism. METHODS. BCVA was measured and spectral domain optical coherence tomography (SD-OCT) images were acquired for 74 individuals with albinism. Categorical foveal hypoplasia grades were assessed using the Leicester Grading System for Foveal Hypoplasia. Foveal anatomical specialization (foveal versus parafoveal value) was quantified for inner retinal layer (IRL) thickness, outer segment (OS) length, and outer nuclear layer (ONL) thickness. These metrics, participant sex, and age were used to build a multiple linear regression of BCVA. This combined linear model's …

The Effect Of Sward Height And Bulk Density On Herbage Intake And Grazing Behaviour Of Dairy Cows, C S. Mayne, D Mcgilloway, A Cushnahan, A S. Laidlaw

IGC Proceedings (1977-2023)

The effects of sward height and bulk density on herbage intake and grazing behaviour of dairy cows during 1 hour grazing periods was investigated. Sward factors had a marked effect on dry matter (DM) intake/bite, which ranged from 0.4 to 1.1 g, and this was reflected in hourly intake rates. Intake/bite was largely influenced by sward height, reflecting increased bite depth in taller swards, with inherent differences between swards at low sward heights largely attributable to differences in bulk density (BD). The results indicate that DM intake rates up to 4.0 kg DM/hour can be achieved in short term grazing …

Characterization And Management Of Grassland And Associated Plant Communities On Kodiak Island, Alaska, J David Swanson, M.H. W. Barker

IGC Proceedings (1977-2023)

A range survey on Kodiak Island grazing leases was conducted summers of 1995-96 to update management plans for areas grazed by cattle (Bos tarus) and bison (Bison bison). Ecological site (site) mapping and descriptions were updated, ecological status and grazing use was evaluated. Spatial data were acquired and summarized using Geographic Information System (GIS). New sites were developed for beaches and cliffs to facilitate ecosystem planning and enhance GIS capabilities.

Identification Of Hyperspectral Characteristics Of The Main Plants In Seriphidium Transiliense Desert Grassland, Wenhao Liu, Wanqiang Han, Guili Jin, Ying Li, Ke Gong, Jian Ma, Zhibiao Liu, Jiazin Li, Mengtian Chen

IGC Proceedings (1977-2023)

Ground hyperspectral images of sericite–Artemisia desert grassland in different seasons were obtained by a soc710 VP imaging spectrometer. Analysis of variance was used to extract the main species Seriphidium transiliense, Ceratocarpus arenarius, and Petrosimonia sibirica and the spectral characteristic parameters and vegetation indices of bare land in different seasons. On this basis, Fisher discriminant analysis was used to divide the samples into a training set and test set according to a ratio of 7:3. The spectral characteristic parameters and vegetation indices were used to identify the three main plants and bare land. Results showed that under Fisher discriminant analysis, …

Forage Data Hub – A Platform For Sharing Valuable Datasets For Resilience, Amanda J. Ashworth, L. Marshall, J. J. Volenec, M. Berti, E. Van Santen, C. Williams, V. Gopakumar, J. Foster, V. Picasso, J. Su

IGC Proceedings (1977-2023)

In accord with the necessity to enhance ecosystem services and productivity in food systems, is the increase of data availability at multiple scales and over time. To help meet this need, we discuss the development of a National Forage Data Hub which will act as a platform to curate, share, and analyze data pertaining to forage systems. This centralized hub will leverage existing datasets by bridging multiple sources including forage crop—soil, water, and nutrient availability—yield (animal and crop) potential (and gaps)— climate—management systems at high spatial and temporal resolution enabling system interaction assessments through next-generation analytics. This novel approach to …

Guidelines For Optimal Use Of Near Infrared Spectroscopy (Nirs) With Sample Preparation And Presentation Across Instrument Platforms, D. W. Mcintosh

IGC Proceedings (1977-2023)

Guidelines for optimal use of near infrared spectroscopy (NIRS) with sample preparation and presentation across instrument platforms will cover methods and resources specifically for NIRS analysis. Recommendations for sample preprocessing and scanning required to ensure compatibility across calibrations will be highlighted. Proper calibration determinations, monitoring, and performance will be demonstrated to create a baseline for correct use. Additional materials about the use and reporting of nutritive content predictions for publication will be discussed. Goals of this topic session are to develop an understanding of the basics of NIRS technology and provide the basics to what a laboratory is required to …

Virtual Fencing Predictable For Cattle? A Simple Method To Test Whether And How Fast Cattle Can Learn The Association Between Acoustic Signal And Electric Pulse, D. Hamidi, M. Komainda, N. Grinnell, L. Wilms, F. Reisch, J. Horn, M. Hamidi, J. Isselstein

IGC Proceedings (1977-2023)

Virtual fencing (VF) offers promising future prospects for improved grazing management as it has the potential to simplify fencing. VF lines are easily drawn and shifted via GPS coordinates. A VF collar emits an acoustic signal when the animal approaches the VF line. The signal stops immediately when the animal turns around. If the animal continues to move towards the VF line, a short electric pulse is emitted. A teaching and an operating mode are provided by the VF collars. The animals automatically change mode when they respond correctly to 20 consecutive acoustic signals without receiving an electric pulse. A …

More Than A Fencing System? Testing The Validity Of Virtual Fencing Collars For Animal Monitoring On Pasture, D. Hamidi, M. Komainda, N. Grinnell, F. Reisch, J. Horn, M. Hamidi, I. Traulsen, J. Isselstein

IGC Proceedings (1977-2023)

High labour requirements for fencing and animal monitoring appear to be general obstacles for the wider use of pastureland for grazing livestock. Virtual fencing (VF) enables a less laborious pasture management. Fence lines can be easily drawn and moved using GPS data. The advantages of VF for reducing the labour inherent to controlled grazing management are obvious. Potential additional animal monitoring opportunities arising from such a VF system that uses real-time GPS data have not yet been studied. Lying is seen as an indicator for assessing comfort or restlessness of cattle. Therefore, we focus on lying behavior in this evaluation. …

Modeling The Biomass Production Of Grasslands Of Wallonia According To Their Functional Type, U. Kokah Essomandan, D. Knoden, B. Dumont, J. Bindelle

IGC Proceedings (1977-2023)

Permanent grasslands are complex ecosystems which respond with a great variability - in terms of specific richness - to soil type and management strategies. Modelling is a valuable tool to explore these relationships. Our work consisted in adapting the Moorepark St Gilles grass growth model (MoSt GG) designed to model Lolium perenne plant functional type (PFT) pastures (PFT A) to a different PFT (Dactylis glomerata, PFT B) through literature-based parametrization. The model was evaluated under Walloon (Belgium) conditions using growth trials from 2014 to 2018 in two sites with contrasting pedo-climatic conditions. Three to five cuts were performed …

Predicting Forage Provision Of Grasslands Across Climate Zones By Hyperspectral Measurements, F. A. Männer, J. Muro, J. Ferner, S. Schmidtlein, A. Linstädter

IGC Proceedings (1977-2023)

The potential of grasslands’ fodder production is a crucial management measure, while its quantification is still laborious and costly. Remote sensing technologies, such as hyperspectral field measurements, enable fast and non-destructive estimation. However, such methods are still limited in transferability to other locations or climatic conditions. With this study, we aim to predict forage nutritive value, quantity, and energy yield from hyperspectral canopy reflections of grasslands across three climate zones. We took hyperspectral measurements with a field spectrometer from grassland canopies in temperate, tropical and semi-arid grasslands, and analyzed corresponding biomass samples for their quantity (BM), metabolizable energy content (ME) …

Regenera+.Uy: Designing A Co-Innovation Process To Apply The Principles Of Regenerative Livestock Production, Oscar Blumetto, M. Bustamante, A. Castagna, D. Caresani, G. Ciappesoni, R. Baptista, I. De Barbieri

IGC Proceedings (1977-2023)

Consumers around the world are beginning to demand products whose production systems have environmental guarantees. Among them, those derived from regenerative agriculture have a growing demand in many markets. A comprehensive environmental assessment was carried out in 9 case studies of mixed livestock production farms (cattle and sheep) in Uruguay as a basis for the development of a system redesign process following the principles of regenerative agriculture. The results show that emission intensity was 16.0, 10.5, and 49.2 kg CO2 eq kg-1 of beef, sheep meat, and greasy wool, respectively. Also, a simulation exercise shows a significative reduction of emission …

Below Ground Benefits Of Cactus Opuntia Stricta Under Rangeland Conditions In Laikipia, Kenya, K. T. Oduor, Jose C. B. Dubeux, W. O. Owino, M. Ruiz-Moreno, L. M. D. Queiroz, I. L. Bretas

IGC Proceedings (1977-2023)

Cactus Opuntia stricta primarily invades arid and semi-arid lands (ASALs), which form more than 80% of Kenya’s landmass. The ability of the plant to tolerate poor soils and accumulate biomass under low precipitation has resulted in studies into its potential use by pastoral communities for biofuel and livestock feed. However, few studies have assessed the below-ground benefits associated with cactus under rangeland conditions. In this study, we evaluated the root contributions of the invasives cactus Opuntia stricta under rangeland conditions in Laikipia, Kenya. The experiment was laid out in a randomized complete block design with ten (10) replicates, each measuring …

Condensed Tannins And Total Phenols In Stylosanthes Spp., M. V. F. Santos, J. P. Muir, O. F. Oliveira, I. M. Macêdo, W. P. S. Diniz, M. V. Cunha, José C. B. Dubeux Jr., M. A. Lira, R. L. C. Ferrreira

IGC Proceedings (1977-2023)

Rangelands, such as the species of the genus Stylosanthes, are plants highly selected by animals and represent an important forage source for livestock in the Northeast region of Brazil. Plants of this genus are naturally occurring in several places in Brazil and other semi-arid areas. The variability of condensed tannins and total phenols in different Stylosanthes accessions is still poorly characterized. Based on that, the objective of this study was to quantify the content of condensed tannins and total phenols of Stylosanthes accessions collected in different physiographic zones of the State of Pernambuco and cultivated in germplasm banks. The …

Forage Production Is Not Changed In Dwarf Elephantgrass Swards Managed In A Wide Range Of Pre-Grazing Canopy Heights, V. Y. M. Moncada, K. C. Vargas, D. A. Barreta, D. S. Comassetto, F. C. S. Gislon, E. R. Ribeiro, D. Moraes, A. F. Sbrissa

IGC Proceedings (1977-2023)

Height corresponding to the critical leaf area index (LAI) has been successfully used to define pre-grazing management targets in pastures subjected to intermittent stocking. However, studies on short/stoloniferous grasses have demonstrated that it is possible to manage pastures at heights below those corresponding to the critical LAI (with a threshold grazing height of approximately 65% of those corresponding to the critical LAI) and achieve a similar forage yield, provided that the severity of defoliation does not exceed 50 percent of the pre-grazing height. In this study, we hypothesized that in tall tussock grasses (such as elephant grass), the amplitude of …