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Nebraska Grazing Conference Proceedings, 2017, Center For Grassland Studies, University Of Nebraska-Lincoln

Nebraska Grazing Conference Proceedings

Fences and Water Points: Where They Should Go by Jim Gerrish

Beef Systems Initiative by Archie Clutter

Grass-based Health and the Ruminant Revolution by Peter Ballerstedt

The Good, Bad, and Ugly of Weedy Plants by Chris Helzer

2016 Leopold Conservation Award Winner by Nancy Peterson

Managing Grassland Vegetation to Benefit Livestock and Wildlife by Patricia Johnson

What is Plant Cover, and How Can We Manage it for Wildlife Needs? by Dwayne Elmore

Producer Panel: Annual Forages vs Row Crops Under Irrigation moderated by John Maddux

Producer Panel: Economics of Grazing Strategies moderated by Jim Jankins

It Costs How Much!? by …

Evaluating Ventilation Rates Based On New Heat And Moisture Production Data For Swine Production, Yanxi Lu, Morgan D. Hayes, John P. Stinn, Tami M. Brown-Brandl, Hongwei Xin

Biosystems and Agricultural Engineering Faculty Publications

Heat and moisture production (HMP) rates of animals are used for calculation of ventilation rate (VR) in animal housing. New swine HMP data revealed considerable differences from previously reported data. This project determined new design VRs and evaluated differences from previously recommended VRs. The swine production stages evaluated included gestation, farrowing, nursery, growing, and finishing. The ranges of ambient temperature and ambient relative humidity (RH) evaluated for VR were -25°C to 15°C in 10°C increments and 15% to 75% in 15% increments, respectively. Indoor set points for temperature and RH were, respectively, 15°C, 20°C, 25°C and 60%, 70%, 80% for …

Physically Adjusted Neutral Detergent Fiber System For Lactating Dairy Cow Rations. I: Deriving Equations That Identify Factors That Influence Effectiveness Of Fiber, Robin R. White, Mary Beth Hou, Jeffrey L. Firkins, Paul J. Kononoff

Department of Animal Science: Faculty Publications

Physically effective neutral detergent fiber (peNDF) is the fraction of neutral detergent fiber (NDF) that stimulates chewing activity and contributes to the floating mat of large particles in the rumen. Multiplying dietary NDF by particle size has been used as an estimate of peNDF. In re-evaluating the concept of peNDF, we compared the use of peNDF as dietary NDF × particle size with the use of individual NDF and particle size descriptors (physically adjusted NDF; paNDF) when used with other physical and chemical diet descriptors to predict dry matter (DM) intake (DMI), rumination time, and ruminal pH in lactating dairy …

Expression Of Cytokine Genes And Receptors In White Blood Cells Associated With Divergent Body Weight Gain In Beef Steers, Amanda K. Lindholm-Perry, Virginia M. Cederberg, Jeremy R. Miles, Andrew P. Foote

Department of Animal Science: Faculty Publications

Previous work examining the transcriptome of steer tissue samples from animals with divergent gain have shown a relationship with the expression of genes with functions in immune and inflammatory pathways. The process of mounting an immune or inflammatory response is energetically expensive and variation in cytokine responses may affect cattle production traits. In addition, a previous study has identified variation in the transcript abundance of numerous genes, including the cytokine gene IL6ST, in the circulating white blood cells of pigs associated with high and low residual feed intake (RFI) lines. The aim of this study was to determine whether …

Genomics Symposium: Using Genomic Approaches To Uncover Sources Of Variation In Age At Puberty And Reproductive Longevity In Sows, Hiruni R. Wijesena, Clay A. Lents, Jean-Jack Riethoven, Melanie D. Trenhaile-Grannemann, Jennifer F. Thorson, Brittney N. Keel, Phillip S. Miller, Matt Spangler, Stephen D. Kachman, Daniel C. Ciobanu

Department of Animal Science: Faculty Publications

Genetic variants associated with traits such as age at puberty and litter size could provide insight into the underlying genetic sources of variation impacting sow reproductive longevity and productivity. Genomewide characterization and gene expression profiling were used using gilts from the University of Nebraska–Lincoln swine resource population (n = 1,644) to identify genetic variants associated with age at puberty and litter size traits. From all reproductive traits studied, the largest fraction of phenotypic variation explained by the Porcine SNP60 BeadArray was for age at puberty (27.3%). In an evaluation data set, the predictive ability of all SNP from highranked 1-Mb …

Effect Of Partially Replacing A Barley-Based Concentrate With Flaxseed-Based Products On The Rumen Bacterial Population Of Lactating Holstein Dairy Cows, E. Castillo-Lopez, J. Moats, N. D. Aluthge, H. A. Ramirez Ramirez, D. A. Christensen, T. Mutsvangwa, G. B. Penner, S. C. Fernando

Department of Animal Science: Faculty Publications

Aims: The effects of partial replacement of a barley-based concentrate with flaxseed-based products on the rumen bacterial population of lactating Holstein dairy cows were evaluated. Methods and Results: Treatments fed were CONT, a normal diet that included barley silage, alfalfa hay and a barley-based concentrate that contained no flaxseed or faba beans; FLAX, inclusion of a nonextruded flaxseed-based product containing 55-0% flaxseed, 37-8% field peas and 6-9% alfalfa; EXT, similar to FLAX, but the product was extruded and EXTT, similar to FLAX, but product was extruded and field peas were replaced by high-tannin faba beans. The rumen bacterial population was …

A Potential Role For Mtorc1/2 In Β2 Adrenergic Regulation Of Skeletal Muscle Glucose Oxidation In Models Of Intrauterine Growth Restriction, Robert J. Posont, Caitlin N. Cadaret, Taylor L. Barnes, Dustin T. Yates

Department of Animal Science: Faculty Publications

The epidemic of intrauterine growth restriction (IUGR) continues to be a leading cause of perinatal morbidity and mortality throughout the world. This condition has been linked to the development of metabolic health problems such as obesity, hypertension, glucose intolerance, and type 2 diabetes at all ages. Previous studies have demonstrated that IUGR fetal adaptations impair proper glucose homeostasis in part via changes in insulin responsiveness in key tissues including skeletal muscle and liver, and that these deficits persists into adulthood. Many components of insulin signaling pathways associated with glucose metabolic regulation have been evaluated in IUGR tissues for adaptive changes. …

Identification Of Candidate Cellulose Utilizing Bacteria From The Rumen Of Beef Cattle, Using Bacterial Community Profiling And Metagenomics, Lee Opdahl

Electronic Theses and Dissertations

The ruminal microbiome allows ruminant animals to convert cellulosic biomass into food products. A majority of ruminal microorganisms remain uncharacterized due, in part, to the complexity of ruminal microbial communities. In order to gain further insight, selection-based batch culturing from bovine rumen fluid, in combination with metagenomics, was used to identify and characterize previously uncharacterized rumen bacteria capable of metabolizing cellulose, which was supplemented as a purified substrate. 16S rRNA-based population analysis was used to identify rumen bacteria enriched within 14 days of culturing. As a result of 4 independent experiments, seven different candidate cellulose-utilizing species-level operational taxonomic units (OTUs) …

Evaluation Of The Deadwood Bighorn Sheep Herd Translocation, Ty J. Werdel

Electronic Theses and Dissertations

From 2015-2017, we evaluated a newly established bighorn sheep (Ovis canadensis) herd in the Deadwood Region of the Black Hills, South Dakota. Our objectives were to 1a) determine annual survival rates, 1b) determine cause-specific mortality, 1c) estimate population size, 2a) assess genetic diversity, 2b) assess disease prevalence, 3) evaluate movement patterns post-release, 4a) evaluate 3rd-order habitat selection, and 4b) estimate herbaceous biomass at foraging sites post-release of translocated bighorn sheep. In February 2015, we captured and translocated 26 bighorn sheep from the Luscar Mine near Hinton, Alberta, Canada to the Deadwood Region of the Black Hills, South Dakota. Overall annual …

An Evaluation Of Nitrogen Supplementation And Processed Soy Fractions On The Performance Of Cultured Fishes, Brandon M. White

Electronic Theses and Dissertations

World population growth has resulted in an increased demand for a sustainable food supply. This rapid growth coupled with an increased per capita consumption of seafood, has resulted in many of the world’s marine fisheries being over-exploited in an effort to meet the global demand for seafood. Aquaculture has attempted to fill the supply and demand gap created by the dwindling supply of fish in the world’s oceans. Fishmeal (FM) has traditionally been the primary protein ingredient in aquafeeds fed to farm-raised fish, however its unstable supply and increasing price have driven researchers to identify alternative protein sources. Soybean meal …

The Effects Of A Blend Of Essential Oils On Rumen Efficiency Of Lactating Dairy Cows, Kali Linville

Electronic Theses and Dissertations

The objective of this study was to evaluate the effects of SS a blend of commercially available essential oils (EO) on rumen microbial efficiency and kinetics, and consequently, effects on production parameters of dairy cows fed a low-starch diet and in vitro analysis of varying doses of SS on ruminal fermentation at different stages of lactation. The study consisted of two experiments, the in vivo Experiment 1, was conducted on a commercial robotic dairy in southwest Minnesota outfitted with two Lely Astronaut A4robotic milking units (Goter’s Clay & Dairy Equipment of MN, INC., Pipestone, MN). One hundred-seven Holstein cows were …

Effect Of Ultrasonication On Biofilm Forming Ability Of Common Dairy Sporeformers, Taghreed Almalki

Electronic Theses and Dissertations

Sporeformers are common dairy contaminants, which are of a great concern to the dairy industry. Quality of dairy products is affected by these sporeformers such as Bacillus species, which are a significant cause of spoilage of dairy products. Thermal processes such as pasteurization have been used to inactivate pathogens, but some of the sporeformers and their endospores are resistant to such heat treatments. Beside thermal treatments, various new approaches are being developed to improve the quality of dairy products. Amongst these, ultrasonication is a promising non-thermal technique for the inactivation of thermoduric sporeformers and their endospores. Current study was carried …

Effects Of Phase Feeding During Gestation On Gilt Performance, Offspring Quality And Robustness, Agatha Ampaire

Electronic Theses and Dissertations

A total of 51 gilts in 6 blocks were randomly assigned to one of 3 feeding regimens: Constant (Constant-f), 2.21 kg/d of a standard diet from breeding to d 112 of gestation (1.7 g Lys/kcal ME; 3276 kcal ME/kg); Bump feeding (Bump-f), the standard diet at 2.21 kg/d from breeding to d 89 and 2.61 kg/d from d 90 - 112; Phase feeding (Phase-f ), 2.21 kg/d from breeding to d 89 (1.5 g Lys/kcal ME; 3275 kcal ME/kg) and 2.61 kg/d from d 90 - 112 (2.1 g Lys/Kcal ME; 3290 Kcal ME/kg) over 2 reproductive cycles. Sows received …

Propensity Of Predator Mimicry In Wild Steller's Jays, Trinity C. Tippin

Cal Poly Humboldt theses and projects

Avian vocal mimicry has been described in a variety of contexts, suggesting its function is multifaceted within and across species; however, basic empirical data describing mimetic signal prevalence and context is lacking for numerous species. I examined occurrence and context of mimicked red-shouldered hawk (Buteo lineatus) calls over a 12-month period in a wild population of 49 individually color-marked Steller’s jays (Cyanocitta stelleri) and reviewed the occurrence of the behavior in historic re-sight data. I documented mimicry of red-shouldered hawk calls in 14 of 49 (28.6%) jays during the study. Hawk mimicry occurred more often during …

Integrated Stress And Community Perceptions: Toward An Understanding Of Human-Cougar Tolerance, Lara Brenner

Graduate Student Theses, Dissertations, & Professional Papers

Evidence suggests that cougars (Puma concolor) are beginning to recolonize their traditional range in the Midwestern and Eastern US, returning to a landscape and a social environment that have changed drastically in a century of absence. Any hope of the cougar’s persistence depends on both human tolerance of their presence and on cougar tolerance of disrupted habitat. In this thesis, we took advantage of diverse cougar policy in place in the Western US to explore variation in human attitudes and acceptability of cougars and in the cougar stress response. We validated a process to identify and extract cortisol …

Morphology And Variation In The Gargle Call In A Chickadee Hybrid Zone In Central Illinois, Shannon Marie Regan

Masters Theses

Black-capped (Poecile atricapillus) and Carolina Chickadees (P. carolinensis) have distributions that span the northern and eastern portions of the United States. The areas where these distributions meet are called contact zones and extend from Kansas to New Jersey. Contact zones often have a narrow range of hybridization and usually within these zones of hybridization we will see a mixture of genetic, morphological, and cultural traits. One focus of this project was to compare morphology and genetics of chickadees within and near the largest Illinois contact zone, which has not been done previously. This contact zone was …

Local And Systemic Actions Of Gnrh Relating To Estradiol And Associated Reproductive Parameters In Beef Cattle, Jerica J.J. Rich

Electronic Theses and Dissertations

In cattle, estradiol is responsible for modulating many mechanisms involved in successful reproduction. Specifically estradiol is the primary signal for the initiation of standing estrus (Allrich, 1994), and cattle expressing estrus prior to fixed time AI (FTAI) have been reported to have increased preovulatory estradiol concentrations (Perry and Perry, 2008) and increased pregnancy success compared to animals that did not exhibit estrus (Richardson et al., 2016). Gonadotropin releasing hormone, classically, stimulates estradiol production via the two-cell two-gonadotropin hypothesis (Fortune and Quirk, 1988), and GnRH administered systemically in small doses (5 μg) has been reported to elicit an LH pulse similar …

Genetic Factors Associated With Thermal Tolerance In Grow-Finish Pigs As Measured By Feeding Behavior, Amanda Jeanne Cross

Electronic Theses and Dissertations

The objectives of this study were: one, use electronic monitoring to determine feeding behavior patterns of grow-finish pigs throughout the year and to identify changes that occurred during heat stress events, and second, identify genetic markers associated with changes in feeding behavior due to heat stress. Pigs were placed in a grow-finish barn at approximately eight to ten weeks of age in 6 pens of 40 animals and monitored for 4-months. Gilts and barrows were from three different sire breeds, Duroc, Landrace, and Yorkshire. Each pen had one feeder, designed to feed 5 animals at a time. Feeders were fitted …

Biofilm Formation By Common Dairy Sporeformers On Native And Modified Stainless Steel Surfaces, Shivali Jindal

Electronic Theses and Dissertations

Aerobic sporeformers can be traced in a variety of dairy products such as milk powders, evaporated milk, and canned products, which demonstrates their capability of resisting high temperature treatments such as pasteurization and Ultra high temperatures. These bacilli also actively attach to the stainless steel surfaces, consequently resulting in the formation of biofilms. Product quality as well as its safety is undesirably affected by the growth of these sporeforming bacteria. Therefore, creating an ideal environment for the processing of dairy products is a critical challenge for the dairy industry. Hence, the objective of this research was to analyze various surface …

Lysine Bioavailability Of Two Lipid Coated Lysine Products After Exposure To Silages With Different Acidity, Jessica N. Reiners

Electronic Theses and Dissertations

Three experiments were conducted to determine bioavailability of 2 lipid coated Lys products (EB and EC). In an initial experiment, Lys disassociation from 2 lipid coated Lys products was best described by a first-order kinetic model after incubation in alfalfa- or corn-silage at 2 different amounts of acidity. Greater amounts of Lys immediately disassociated from EC (15.7%) than EB (4.9%; P < 0.05). Lysine that initially disassociated in corn silage at low pH (0.5%) was less than corn silage at a more neutral pH (18.7%), whereas Lys that initially disassociated in alfalfa silage was not affected (P = 0.26) by pH. Lysine that slowly disassociated from lipid coated Lys differed by product (P = 0.01), and acidity (P < 0.01) affected amounts of Lys that slowly disassociated differently within alfalfa- or corn-silage (pH × silage = 0.02). Greater amounts of Lys disassociated from acidic corn silage (79%) than neutral corn silage (32%; P = 0.01). However, amounts of Lys that slowly disassociated from alfalfa silage was not impacted by acidity (P = 0.40). Additionally, amounts of Lys that did not disassociate (P < 0.04) within 24 h were greater (P < 0.04) when lipid coated Lys was mixed with neutral silages (44%) compared to acidic silages (21%). However, rate of Lys disassociation from lipid coated Lys products was not affected by acidity or exposure to alfalfa- or corn-silage (P = 0.21). In a second experiment, we measured in vitro ammonia release from EB and EC after mixing with alfalfa- or corn-silage at different amounts of acidity with or without monensin. Ammonia release from Lys increased (Quadratic < 0.01) with greater amounts of time; however, differences between in vitro cultures with added Lys and negative control were not detected until 36 h of incubation. By 36 h, all cultures containing added Lys were greater than the negative control. After 42 h of incubation, ammonia release from Lys was greatest from EC and when lipid and Lys-HCl in amounts identical to EB were provided to cultures; EB, Lys-HCl, and lipid and Lys in amounts identical to EC were intermediate. After 48 h of incubation, ammonia release from Lys in EB was greatest and Lys-HCl was least, but EC and amounts of lipid and Lys-HCl identical to either EB or EC were intermediate. Ammonia release from Lys were less from cultures containing monensin after 48 h of incubation. In experiment 3, 9 white-faced ewes (70.1 ± 5.2 kg BW; 5.3 ± 0.6 yr) were used to measure Lys bioavailability by a slope-ratio analysis from 2 lipid coated Lys products and Lys-HCl after mixing in corn silage. Plasma Lys concentrations increased (Linear < 0.01) in response to abomasal infusion of Lys, and bioavailability of EB, EC, and Lys- HCl were calculated to be 10.74%, 18.82%, and 11.87%, respectively. However, increases in plasma Lys from EB (Linear = 0.41) and Lys-HCl (Linear = 0.36) were not different from plasma Lys supported by diet alone, but the rate of increase in plasma Lys in response to EC tended (Linear = 0.15) to be greater than plasma Lys levels from diet. Evidently, manufacturing method among lipid coated Lys products as well as physical and chemical characteristics of diet can impact availability of Lys from lipid coated Lys products.

Evaluation Of Supplementing Brewer's Yeast To Lactating Dairy Cows, Taylor Christine Aubrey

Electronic Theses and Dissertations

Probiotics have been used as effective, natural feed additives in the dairy industry to improve animal health and performance. Yeast product supplementation can be beneficial in the diet of lactating dairy cows by increasing feed efficiency, alleviating disease, and improving production performance under heat stress. Objectives of this study were to evaluate supplementing a concentrated brewer’s yeast in the ration of a lactating dairy cow by assessing milk yield and composition, blood metabolites, rumen fermentation, and feed intake and efficiency. We hypothesized that diets containing a concentrated brewer’s yeast supplement would increase milk and component yields, benefit rumen fermentation, and …

The Influence Of Chromium Supplementation On The Insulin Pathway, Carcass Traits, And Meat Quality Of Feedlot Steers, Heather Rode

Electronic Theses and Dissertations

Chromium supplementation (Cr) can increase efficiency of growth in livestock by amplifying insulin signaling. Previous research showed Cr increases nutrient utilization and changes in muscle growth and fat deposition. Therefore, the objective of this research was to determine how Cr affects carcass traits, meat quality, and the insulin pathway in feedlot steers. Calf-fed steers were allotted to 0 ppb (CON) or 400 ppb Cr propionate (Cr400) for 210d in experiment 1. Two longissimus muscle (LM) biopsies were collected to examine protein abundance and gene expression after adaptation to a terminal implant and after adaption to ractopamine hydrochloride (RAC). A follow …

Effective Use Of Probiotic-Glyconutrient Combination As An Adjuvant To Antibiotic Therapy For Diarrhea In Rearing Dairy Calves, Gilberto Lopez Valencia, Octavio Zapata-Ramirez, Lilia Núñez-González, Victor Núñez-Benítez, Heriberto Landeros- López, Maria Lopez-Soto, Alberto Barreras Serrano, Victor Gonzalez-Vizcarra, Alfredo Estrada-Angulo, Richard Zinn, Alejandro Plascencia

Turkish Journal of Veterinary & Animal Sciences

Thirty Holstein calves presented with infectious diarrhea during the second week following birth were utilized to evaluate the effects of a standardized product containing a combination of probiotics, ß-glucans, and glyconutrients (GLY) in support of antibiotic therapy during the early rearing phase (day 7 to day 45 following birth). Treatments were 1) antibiotic therapy (trimethoprim and sulfas; ANTIB), and 2) ANTIB plus 5 g/calf per day GLY. Treatments did not affect diarrhea duration, averaging 16.7 days. However, GLY support decreased (P < 0.05) the mortality rate and increased (P < 0.05) live weight gain. Increased weight gain was attributable to enhanced (P < 0.05) consumption of calf starter. Supplemental GLY increased (P < 0.05) serum glucose and lowered (P < 0.05) serum urea nitrogen, nonesterified fatty acids, and cortisol concentration. We conclude that daily provision of 5 g of a standardized product containing probiotics, ß-glucans, and glyconutrients to diarrheic calves under antibiotic therapy will promote health and enhance early growth performance.

News Of The Department Of Animal Science, Department Of Animal Science

Animal Science Newsletters

No abstract provided.

Species Diversity And Community Structure Of Zooplankton In Threedifferent Types Of Water Body Within The Sakarya River Basin, Turkey, Pinar Gürbüzer, Özge Buyurgan, Çağri Tekatli, Ahmet Altindağ

Turkish Journal of Zoology

The aim of this study was to identify differences between different types of water body within the same river basin by comparing the composition of the zooplankton community. The study was conducted in three types of water body in the Sakarya Basin in northwestern Turkey: an alluvial barrier lake (Lake Poyrazlar), a pond (Sorgun Pond), and a reservoir (Çubuk II Reservoir). The spatiotemporal changes of these three types of aquatic habitats were investigated in terms of the zooplankton organisms by examining their diversity, evenness, and differences in the abundance of species. A total of 81 species were identified. Thirty-eight species …

Food Patch Particularity And Forging Strategy Of Reintroduced Przewalski's Horse In North Xinjiang, China, Zang Sen, Cao Qing, Alimujiang Keremu, Liu Shanhui, Zhang Yongjun, Hu Defu

Turkish Journal of Zoology

In 2001, Przewalski's horse (Equus przewalskii) was reintroduced into a Eurasian desert-steppe transitional area in China. Recent studies of Przewalski's horse have not examined the relationship between food patches and the horse's feeding choice behavior. This study aimed to study the vegetation communities of the reintroduction area and combine this information with feeding time data to explore the foraging strategy of Przewalski's horse. A total of 588 vegetation patches were surveyed, which were divided into 27 vegetation clusters. All vegetation clusters could be divided into feeding clusters, which constituted 59.23% of the study area, and nonforaging clusters, which constituted 11.14%. …

Effects Of Equine Assisted Activities And Therapies On Equine Stress And Welfare, Sarah Jean Reega

Honors Theses and Capstones

Equine assisted activities and therapies (EAATs) are becoming an increasingly popular approach for therapy, therapeutic recreation, and learning for a broad range of human clients and participants. In the EAAT field, most research has been human-centric, focusing primarily on benefits of EAATs for participants and clients. Relatively little research has been conducted on the effects of EAATs on equine stress and welfare for equines engaged in EAAT sessions.

The effects of equine assisted activities and therapies on equine stress and welfare were studied by way of exploring current EAAT professionals’ experiences and views related to equine stress and welfare in …

Precision Dairy Farming Technology Solutions For Detecting Dairy Cow Disease To Improve Dairy Cow Well-Being, Amanda Stone

Theses and Dissertations--Animal and Food Sciences

Dairy cow health is multifactorial and complex. High producing dairy cows have been described as metabolic athletes, but metabolic and infectious diseases around calving affect many cows. These diseases have drastic negative effects on dairy cow well-being, milk production, and dairy farm economics. Early disease detection could potentially improve disease management, treatment, and future prevention techniques. The first objective of this research was to evaluate the use of activity, lying behavior, reticulorumen temperature, and rumination time determined by precision dairy farming technologies to detect transition cow diseases including hypocalcemia, ketosis, and metritis. The second objective was to evaluate the ability …

Influence Of Ergot Alkaloids On Rumen Motility: Time And Concentration Of Ergovaline + Ergovalinine Required To Impact Reticulorumen Motility, Kara Riccioni

Theses and Dissertations--Animal and Food Sciences

Fescue toxicosis is problematic for ruminant livestock, causing weight loss and low productivity when fed endophyte-infected forages. Complete underlying mechanisms of toxicosis are unknown therefore; the objective of the study was to determine if ruminally dosed ergot alkaloids impact rumen motility. Cannulated steers were pair-fed a forage diet and ruminally dosed with endophyte-free (E-) or endophyte-infected (E+) tall fescue seed. An 8-h period of rumen motility collection began 4-h after feeding by monitoring pressure change via a wireless telemetry and transducer system. In experiment 1, steers were paired by weight and assigned to E- or E+ treatment. Overall, E+ steers …

Assessment Of Bovine Vascular Serotonin Receptor Populations And Transport Of Ergot Alkaloids In The Small Intestine, Miriam A. Snider

Theses and Dissertations--Animal and Food Sciences

Prior work using a contractility bioassay determined that the serotonin (5-HT) receptor subtype 5-HT_2A is present in bovine lateral saphenous veins and plays a role in ergot alkaloid-induced vascular contraction in steers grazing endophyte-infected (Epichloë coenophiala) tall fescue (Lolium arundinaceum). A study was conducted to determine what 5-HT receptors are involved in vasoconstriction of bovine gut vasculature. The findings of this study indicate that 5-HT_2A is present and may play a role in ergot alkaloid induced vasoconstriction. A second study was conducted to determine if ergot alkaloids were transported in the small intestine. The …