Life Sciences Commons^™

Yield And Nutritive Quality Of Fresh And Ensiled Reduced Lignin Alfalfa In Monoculture And Diculture With Novel Tall Fescue, Morgan Boss

All Theses

The objectives of this research were to: (1) evaluate the yield, nutritional value, and digestibility of fresh and ensiled reduced lignin alfalfa (RLA; Medicago sativa L.) in monoculture and when mixed with novel endophyte-infected tall fescue (F; Festuca arundinacea) in comparison to a conventional alfalfa (CA) cultivar; and (2) evaluate ensiled samples under varying DM concentrations; with or without inoculant. A trial was prepared as a randomized complete block design with 4 replicates per treatment. Treatments included reduced lignin alfalfa (RLA), conventional alfalfa (CA) and tall fescue (F) plots as well as RLA/F and CA/F plots. Plots were harvested on …

Forage Grass Growth Habit And Allelopathy In Birdsfoot Trefoil Germination And Establishment, Nathan El Blake

Graduate Theses, Dissertations, and Problem Reports

Birdsfoot trefoil (Lotus corniculatus L.) (BFT) is a high quality, tanniniferous forage legume that has been shown to mitigate gastrointestinal nematode (GIN) infection in sheep. Reliable establishment of birdsfoot trefoil in existing pastures is difficult due to BFT’s poor seedling vigor, susceptibility to crown and root rot, and, perhaps chiefly, competition from other pasture plants. Most existing pastures in the Northeastern United States are primarily composed of cool-season grasses, many of which can be highly competitive. A common form of interplant competition is allelopathy, which occurs when secondary metabolites produced by a plant inhibit a necessary growth process of …

Unmanned Ground Vehicle Proximal Sensing For Forage Biomass Production Estimations, Curtis Erwin

All Theses

A large increase in productivity could be realized by small increases in efficiency and utilization on grasslands due to their large area. Pre-harvest biomass estimations can help forage producers make better informed management decisions. Producers of dry hay and hay silage can better identify plant growth stages and the optimal time to harvest. Grazers can better determine the most efficient number of animals and stocking density. The goal of this study was to create a novel pre-harvest biomass estimation method utilizing compressed height combined with an unmanned ground vehicle (UGV). A compression plate named a “compression ski” was constructed and …

Manipulating Species Diversity: Environmental Impacts In Row Crop, Livestock, And Grassland Agroecosystems, Alayna A. Jacobs

Theses and Dissertations--Plant and Soil Sciences

The diversity of living species in an agroecosystem affects both natural resources and agricultural production efficiency. The rise of managed plant monocultures has allowed agricultural yields to increase over time. However, simplifying agroecosystems affects the capacity of the system to sustainably provide clean air, water, and productive soils essential for continued food and fiber production. This dissertation manipulates species diversity in row crop and forage agroecosystems prevalent in the Eastern United States and tracks the associated environmental and agricultural production consequences.

In row crop agroecosystems, increasing plant diversity with winter cover crops has been suggested as a strategy to increase …

Estancia Vs. Kentucky 31: Examining Leaf Nutrient Content Of Established Tall Fescue, Macie W. Clark

MSU Graduate Theses

In 2020 Missouri ranked third in beef cattle production and second in hay production. As part of the fescue belt of the United States, Missouri’s agricultural industries rely on tall fescue (Lolium arundinaceum Schreb.) as a main forage crop. Two major disorders in cattle grazing tall fescue are fescue toxicosis and grass tetany. Fescue toxicosis occurs when animals consume toxic ergot alkaloids produced by an endophyte within the tall fescue plants. The most commonly grown tall fescue variety, Kentucky 31, is infected with the toxic endophyte. Varieties containing a novel non-toxic endophyte, such as Estancia, have been developed to …

Forage Species Selection For Transitional Organic Production In The Southeastern United States, Jonathan Kubesch

Masters Theses

Despite the vast production markets for forage and organic products nationally, so far limited work has been done to develop organic forages specifically for Middle Tennessee or the mid-South in general. The present organic research field focuses on vegetable and grain production; however, forage production offers an easier transition for producers moving into certified organic agriculture. The present study seeks to evaluate several forage blends for optimizing forage production under low-input transitional organic conditions. Ideally a forage system could be tailored to the beef cattle operations of Middle Tennessee, the dominant forage consumption market in this region of the mid-South. …

Forage Quality Of Cool Season Perennial Grass Horse Pastures In The Transition Zone, Annmarie Christine Riley

Theses and Dissertations--Plant and Soil Sciences

Cool season perennial grasses are the foundation of equine nutrition in the transition zone. The objective of this study was to evaluate forage quality using ADF, NDF, IVTDMD, CP, WSC, and ESC and changes in vegetative swards seasonally, diurnally, across species (Kentucky bluegrass, tall fescue, orchardgrass, and perennial ryegrass) and cultivar. This study was conducted in 2015 and 2017 and plots were maintained vegetatively with two to four week mowing. Morning and afternoon sample collection occurred monthly during the growing season. Samples were flash frozen; freeze dried, ground, and scanned using Near Infrared Reflectance Spectroscopy (NIRS) to predict forage quality. …

Alternative Feeding Strategies For Growing Cattle Grazing Endophyte-Infected Tall Fescue During The Summer, Kerri A. Johnson

MSU Graduate Theses

Two experiments were conducted to determine animal performance of alternative feeding strategies to heifers grazing endophyte-infected tall fescue during summer months. In Experiment 1, 40 Limousin heifers (261± 40kg initial BW) were stratified by weight and assigned to either a spring harvested tall fescue silage diet or grazing endophyte-infected tall fescue pasture with grain supplement having either natural or artificial shade for 80 days. In Experiment 2, 40 Limousin heifers (277 ± 44kg initial BW) were stratified by weight and assigned to either a traditional grain supplement or feather-meal supplement (rumen bypass arginine supplement) with natural or artificial shade while …

Can Increasing Grass-Fungal Endophyte Symbiotic Diversity Enhance Grassland Ecosystem Functioning?, Mahtaab Bagherzadeh

Theses and Dissertations--Plant and Soil Sciences

The relationship between biodiversity and ecosystem functioning is important in maintaining agroecosystem sustainability. Plant-microbe symbioses, such as exists between the grass tall fescue (Schedonorus arundinaceum) and the asexual fungal endophyte Epichloë coenophiala, can be utilized to enhance agroecosystem functions, such as herbivore resistance. “Novel” E. coenophiala strains that vary in the production of mammal- and insect-toxic compounds have been identified, inserted into tall fescue cultivars, and are planted in pastures globally. Novel fungal endophyte-tall fescue associations may have divergent ecosystem function effects. This study assessed effects of different fescue-endophyte symbiotic combinations on pasture ecosystem function, including aboveground …

Physiological Changes Associated With Pregnant Or Nonpregnant Mares Grazing Pastures Of Orchardgrass-Bluegrass, Kentucky 31 Tall Fescue Infected With Epichloë Coenophiala, Or Kyfa9821 Tall Fescue Infected With The Novel Endophyte Ar584, Victoria A. Taylor

Theses and Dissertations--Veterinary Science

Kentucky 31 tall fescue (KY31) infected with the common toxic endophyte strains of Epichloё coenophiala produces toxic alkaloids that improve plant vigor, but cause numerous adverse effects in grazing animals. Researchers developed a variety of KY31 containing an alternative strain of E. coenophiala, termed novel endophyte (NE). Adverse health effects in mares have not been evaluated.

Experiments in this thesis tested the hypothesis that the NE pasture does not cause adverse effects typically associated with KY31. Specific aims were to: 1) compare forage ergovaline concentrations between KY31 vs NE pastures; 2) evaluate palmar artery diameters in mares grazing KY31, …

The Effects Of Phosphorus And Nitrogen Fertilization On Tall Fescue Nutrient Content, Yield And Baleage Quality, Cheyenne Adele Arthur

MSU Graduate Theses

Tall fescue (Festuca arundinacea Schreb.) is a cool season perennial grass commonly used in year-round forage production systems. Producers often wrap large round bales of tall fescue in plastic. The fermented product of this practice, termed baleage, allows the forage to be stored for later feeding. During periods of rapid growth in the spring and the fall, the nutrient content of tall fescue can be imbalanced and cause nutritional disorders in grazing animals. To improve the nutrition of tall fescue, it is known that fertilization of phosphorus (P) can help improve leaf nutrient content of P, magnesium (Mg), and calcium …

Evaluating A Novel Endophytic Grass For Its Potential To Reduce Invertebrate Populations And Associated Bird Strike Risk At Airports, Diana M. Miller

Theses and Dissertations--Entomology

Aircraft strikes are a significant safety hazard on airports worldwide. Wildlife management at airfields is the most effective tactic to reduce airstrike risk – to modify the habitat to be undesirable to animals. Tall fescue grasses containing a fungal symbiont may serve that purpose. They produce alkaloids that convey resistance to some grass-feeding invertebrates, which might in turn reduce incidence of insectivorous birds. A commercial endophytic grass (Avanex™) consisting of ‘Jackal’ tall fescue infected with a unique endophyte (AR 601) is purported to contain especially high levels of alkaloids and to reduce bird populations if planted at airports. I evaluated …

Defining Management Strategies To Maximize Net Soil Carbon And Nitrogen Retention In Turfgrass Systems, Quincy D. Law

Open Access Theses

Soil carbon (C) sequestration has been proposed as a method to reduce atmospheric carbon dioxide (CO2 ). Managed turf areas are both a source and a sink for greenhouse gases (GHGs) including CO 2 , methane (CH4 ), and nitrous oxide (N2 O), among others. Management practices, including turfgrass selection and mowing, influence the amount of C and N stored in the soil, as well as the direct and indirect GHG emissions. Thus, the objective of this research was to determine how turfgrass selection (both species and cultivar) and mowing practices (such as frequency and grass clipping management) influence the …

The Influence Of Tall Fescue Cultivar And Endophyte Status On Root Exudate Chemistry And Rhizosphere Processes, Jingqi Guo

Theses and Dissertations--Plant and Soil Sciences

Tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) is a cool-season perennial grass used in pastures throughout the Southeastern United States. The grass can harbor a fungal endophyte (Epichloë coenophiala) thought to provide the plant with enhanced resistance to biotic and abiotic stress. However, the alkaloids produced by the common variety of the endophyte cause severe animal health issues resulting in a considerable amount of research focused on eliminating the toxic class of alkaloids while retaining the positive abiotic and biotic stress tolerance attributes of the other alkaloids. In doing so, very little attention has been paid to the …

Effect Of Dietary Exposure To Ergot Alkaloids On Contractility Of Bovine Mesenteric Vasculature And Rumen Motility, Amanda M. Egert

Theses and Dissertations--Animal and Food Sciences

Endophyte-infected (E+) tall fescue grass has been associated with fescue toxicosis, a costly syndrome characterized by poor cattle performance and health resulting in significant production losses. The fungal endophyte produces ergot alkaloids, which help the grass thrive in poor conditions but are toxic to mammals. A number of symptoms of fescue toxicosis can be related to vasoconstriction of bovine core, peripheral, and foregut vasculature. The first part of this series of experiments demonstrated ergot alkaloids were also vasoactive in midgut vasculature, with the exception of lysergic acid. Additionally, prior dietary exposure to ergot alkaloids decreased the contractile response of mesenteric …

Preservation Of Nutrients In Cool- And Warm-Season Forages At Different Stages Of Maturity And Management, Jason Allen Shultz

Masters Theses

The overall goals of the studies described in this thesis were to investigate management practices of tall fescue and native warm-season grasses (NWSG) and find the best time to harvest and method to preserve forage quality. Study one investigated the effects of maturity on tall fescue and switchgrass and the effects of preservation method on forage quality. This study confirmed that maturity reduced forage quality in both tall fescue and switchgrass. Both tall fescue and switchgrass were successfully preserved as haylage or hay and did not differ in forage quality. Forages harvested before mid-May met the TDN and CP requirements …

Forage Yield And Quality Of Binary Grass-Legume Mixtures Of Tall Fescue, Orchardgrass, Meadow Brome, Alfalfa, Birdsfoot Trefoil, And Cicer Milkvetch, Steven R. Cox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Managed pasture forms the foundation for much of the U.S. livestock iv production. Increased forage yield and quality can be achieved with nitrogen (N) fertilizer but increases the cost of pasture production. Rising prices of N have led to a return to the use of grass-legume pastures to reduce or replace commercial N fertilizer. There is a need to identify viable grass-legume mixtures and species planting ratios for the region of the Intermountain Western United States The purpose of this study was to identify grass-legume combinations and planting ratios that maximize forage production and forage quality in irrigated pastures. The …

Importance Of Grass-Legume Choices On Cattle Grazing Behavior And Performance, Brody Todd Maughan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Livestock production systems have emphasized low diversity of high-producing forage species dependent upon costly fossil-fuel inputs. However, diversity of plants in natural systems is common, and diverse plant communities enable herbivores to meet needs for nutrition and health. Plants provide herbivores with nutrients and bioactive compounds – plant secondary compounds (SCs), which at appropriate concentrations can reduce internal parasites and greenhouse gas emissions, improve nutrient utilization and enhance meat quality in ruminants. In addition, SCs confer plants more resistance to environmental challenges such as drought or pests.

With my MS program, I sought to explore foraging behavior in cattle grazing …

Effect Of Ergot Alkaloids On Bovine Foregut Vasculature, Nutrient Absorption, And Epithelial Barrier Function, Andrew P. Foote

Theses and Dissertations--Animal and Food Sciences

Ergot alkaloids present in endophyte-infected (E+) tall fescue are thought to be the causative agent of fescue toxicosis, a syndrome affecting cattle in the eastern United States. Many of the observed signs of fescue toxicosis are thought to be attributed to peripheral vasoconstriction; however, there are data indicating that ergot alkaloids can alter blood flow to the gut. An experiment was conducted using right ruminal artery and vein collected from heifers shortly after slaughter. Vessels were mounted in a multi-myograph to determine the vasoconstrictive potentials of ergot alkaloids present in E+ tall fescue. Results indicated ergot alkaloids have the potential …

Utility Of Aminocyclopyrachlor For Control Of Horsenettle And Tall Ironweed In Cool-Season Grass Pastures, William Paul Phillips

Masters Theses

Previous research has shown that management of horsenettle (Solanum carolinense) and tall ironweed (Vernonia gigantea) in cool-season grass pastures and hayfields is difficult. Therefore, research was conducted at Alcoa, Fork Creek, Greenback, Maynardville, and Pulaski, Tennessee, and at London, Kentucky, in 2010 and 2011 to examine efficacy of aminocyclopyrachlor on these two perennial weeds. Research was conducted on naturally-occurring infestations of each weed. Treatments were: aminocyclopyrachlor (49 g ai/ha) with and without 2,4-D amine (371 g ai/ha), aminocyclopyrachlor (98 g ai/ha) with and without 2,4-D amine (742 g ai/ha), and aminopyralid (88 g ai/ha). Treatments were …

Integrated Strategies For Controlling Warm-Season Turfgrass Weeds, Matthew Thomas Elmore

Masters Theses

Herbicidal inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPPD) such as mesotrione, topramezone and tembotrione were evaluated in greenhouse experiments for activity against bermudagrass. While topramezone and tembotrione exhibited greater activity than mesotrione, none of these herbicides provided acceptable bermudagrass control. These herbicides reduced leaf tissue chlorophyll and carotenoid pigment concentrations in bermudagrass. Changes in turfgrass pigmentation were quantified using HPLC analogy as well as evaluations of visual bleaching and measurements of chlorophyll fluorescence yield (F_v/F_m). Results indicated that these more expeditious methods of evaluating HPPD-inhibiting herbicide activity (visual evaluations and F_v/F_m) cannot be used …

Earthworms Of Arkansas And Contributions Of Earthworm Evolutionary Origin And Ecological Group To Nitrogen Cycling In A Model Soil And Tall Fescue System, Peter John Tomlinson

Graduate Theses and Dissertations

Evolutionary origin and ecological niche may impact how earthworm species affect N cycling. Tall fescue (Lolium arundinaceum (Schreb) S. J. Darbysh) infection with the toxic endophyte Neotyphodium coenophialum Glenn, Bacon & Hanlin (E+) may influence earthworm communities in soil compared to non-toxic endophyte (NE+) infected tall fescue. Conversely, different earthworms may contribute different amounts of N to E+ vs. NE+ tall fescue. A field survey was conducted from January 2007 to January 2008 to determine the impact of E+ and NE+ tall fescue, planting date, and seasonal variables, e.g. soil temperature and moisture, on earthworm species, abundances, and population …

Fertilization Characteristics Of Spermatozoa Collected From Bulls Grazing Tall Fescue Pastures, Jessica Pegan Harris

Masters Theses

Consumption of toxic endophyte-infected (E+) tall fescue pastures is known to have a negative impact on bull reproductive performance. Since decreased cleavage rates of embryos fertilized with spermatozoa from bulls grazing E+ tall fescue pastures have been observed in several studies using differing sets of bulls, technicians, pastures, and other methods of inducing tall fescue toxicosis (ergotamine tartrate), it is hypothesized that spermatozoa function from bulls grazing E+ is impaired in ways undetectable by gross semen examination.

During a three-month grazing study, 6 Angus bulls were utilized to determine the effects of grazing E+ tall fescue pastures on growth performance …

Beef Cattle Grazing Preference Of Tall Fescue As Affected By Endophyte, Herbert Troye Owens Iii

University of Kentucky Master's Theses

Many factors control, contribute to, stimulate and limit forage selection. It is apparent that cattle prefer certain cultivars compared to others. This study sought to test if cattle displayed preferences for certain cultivars over a two-year period in 2008 and 2009. Determining the effect of endophyte status on preference was another objective. Previous research showed rapid increase in the selection of preferred cultivars, i.e., diet learning. We attempted to replicate those results. Forty cultivars (34 tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) cultivars), two festuloliums (Festuca pratensis x Lolium perenne), two meadow fescue (Lolium pratense) and one meadow …

Restoration Of Tall Fescue Pastures To Native Warm Season Grasslands: Does A Fungal Endophyte Symbiosis Play A Role In Restoration Success?, Sarah Lynn Hall

University of Kentucky Doctoral Dissertations

Tall fescue, a cool-season grass native to Europe, central Asia, and northern Africa, has been widely distributed throughout the U.S. for use as turf and forage. Following its widespread planting, its ability to associate with a toxic fungal endophyte, Neotyphodium coenophialum, was discovered. Research has linked this fescue-endophyte association with increased biotic and abiotic stress resistance in endophyte-infected (E+) versus endophyte-free (E-) plants, and these differences may affect the ability of land managers to eradicate tall fescue and restore native grasslands. I conducted three studies to examine whether E+ tall fescue plants respond differently to management than E- plants, …

The Response Of Tall Fescue And Its Fungal Endophyte To Climate Change, Glade Blythe Brosi

University of Kentucky Master's Theses

Tall fescue is the most common cool-season grass in the eastern USA, with broad economic and ecological importance to the region. Tall fescue is known to associate with a fungal endophyte, Neotyphodium coenophialum, whose presence can decrease biotic and abiotic stress experienced by the plant. This thesis evaluates the response of tall fescue and the fungal endophyte symbiosis to predicted climate change. I participated in two multi-factor climate change projects where I investigated the response of tall fescue tissue chemistry and growth to various climate change factors. Endophyte-infected (E+) tall fescue had decreased alkaloid production under elevated CO_{2 …}

Management Strategies To Improve Development Of Replacement Heifers Utilizing Tall Fescue-Based Systems, Margaret Miller

All Theses

Research was conducted to determine the effect of tall fescue and alternative management regimens on reproduction in replacement beef heifers. Angus _ Simmental heifers (n = 48; 318 ± 4.99 kg initial BW) stratified by weight and pubertal status were assigned to one of three replicated grazing treatments: (1) toxic endophyte-infected tall fescue (TF); (2) toxic endophyte-infected tall fescue with a soybean oil supplement (TFO); or (3) mixed winter annual species (cereal rye, annual ryegrass, crimson clover and hybrid turnip) (M). Tall fescue endophyte infection level was between 74 and 94%. Pastures were grazed from December 12 to April 24. …