Large or Food Animal and Equine Medicine Commons^™

Trace-Level Identifications Are Not Positives: The Scientifically Correct And Public Relations-Appropriate Approach To Medication Regulation, Clara Fenger, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

No abstract provided.

30-Day Oral Acetaminophen Tolerance In Adult Horses, Sarah E. Foreman

Celebration of Learning

There are no controlled studies of acetaminophen toxicity in horses. The objective was to test the hypotheses that oral acetaminophen administered at a dosage 25% higher than that sometimes used in horses would result in measurable hepatic toxicity as seen in humans and other species. Six healthy adult horses were administered 25 mg/kg acetaminophen powder in corn syrup twice daily for 30 days. Three other horses served as negative controls receiving only corn syrup. Jugular venous blood samples were obtained on days 7 and 1 before treatment; on treatment days 1, 2, 5, 8, 12, 15, 19, 22, 26 and …

Protozoal Coinfection In Horses With Equine Protozoal Myeloencephalitis In The Eastern United States, Sarah Schale, Daniel Howe, Michelle Yeargan, Jennifer K. Morrow, Amy Graves, Amy L. Johnson

Maxwell H. Gluck Equine Research Center Faculty Publications

Background: Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis.

Hypothesis/Objectives: To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites.

Animals: One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM.

Methods: Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses …

Effects Of Fescue Toxicosis On Whole Blood Gene Expression In Beef Cattle, Julie Atchley

Animal Science Undergraduate Honors Theses

Effects of Fescue Toxicosis on Whole Blood Gene Expression in Beef Cattle

The consumption of endophyte-infected tall fescue causes negative effects on the growth, reproduction, longevity, and overall health of beef cattle; this condition, termed fescue toxicosis by researchers and producers today, costs the United States over $1 billion in losses each year. To mitigate these production losses, it is important for producers to understand how fescue toxicosis affects gene expression and physiological pathways in beef cattle. This study examined the whole blood gene expression and affected pathways in beef cows grazing both endophyte-infected (toxic) tall fescue and (non-toxic) tall …

Downregulation Of Microrna Eca-Mir-128 In Seminal Exosomes And Enhanced Expression Of Cxcl16 In The Stallion Reproductive Tract Are Associated With Long-Term Persistence Of Equine Arteritis Virus, Mariano Carossino, Pouya Dini, Theodore S. Kalbfleisch, Alan T. Loynachan, Igor F. Canisso, Kathleen M. Shuck, Peter J. Timoney, R. Frank Cook, Udeni B. R. Balasuriya

Maxwell H. Gluck Equine Research Center Faculty Publications

Equine arteritis virus (EAV) can establish long-term persistent infection in the reproductive tract of stallions and is shed in the semen. Previous studies showed that long-term persistence is associated with a specific allele of the CXCL16 gene (CXCL16S) and that persistent infection is maintained despite the presence of a local inflammatory and humoral and mucosal antibody responses. In this study, we demonstrated that equine seminal exosomes (SEs) are enriched in a small subset of microRNAs (miRNAs). Most importantly, we demonstrated that long-term EAV persistence is associated with the downregulation of an SE-associated miRNA (eca-mir-128) and with an enhanced …

The Effect Of High Maternal Milk Production During Pregnancy On Neonatal Health And Metabolism, Katelynn Cameron, Maria L. Hoffman Phd

Senior Honors Projects

The efficiency of the dairy industry relies heavily on the production of healthy calves. However, dairy operations experience high rates of calf mortality due to digestive and respiratory issues. One factor that could predispose calves to disease is the effects of maternal programming caused by high maternal milk production during pregnancy. We hypothesized that calves born to high producing dams will exhibit increased oxidative stress as well as increased circulating triglyceride and total cholesterol concentrations. Cows (n = 17) that produced ≥ 14,865 kg of milk during their lactations were classified as high producers. Alternately, cows (n = 18) that …

Rational Reasoning On Ractopamine: Kentucky Regulators Reach Appropriate Responses To Inconsequential Trace-Level Environmental Substance Identifications, Theodore F. Shults, Kimberly Brewer, Jake Machin, Eric Hamelback, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

No abstract provided.

An Evaluation Of Pathophysiology And Biomechanics Of Selected Lamenesses In The Horse, Cole Barrett Sandow

LSU Master's Theses

INTRODUCTION-Laminitis and synovitis are two common causes of equine lameness. Laminitis is most often associated with hyperinsulinemia and osteoarthritis is most commonly the result of synovitis. The objective is to evaluate biomechanical and pathophysiologic events regarding laminitis and synovitis.

MATERIALS AND METHODS-The first study evaluated biomechanical effects of insulin on lamellar strength. For this experiment, lamellar explants were harvested, incubated in media only (serving as a control) or media with a high concentration of insulin for 8 hours. After incubation, structural integrity was evaluated with a mechanical testing device. Data included load to failure (N), stress to failure (MPa), elongation …

Streptococcus Equi Infections In Horses: Guidelines For Treatment, Control, And Prevention Of Strangles—Revised Consensus Statement, A. G. Boyle, John F. Timoney, J. R. Newton, M. T. Hines, A. S. Waller, B. R. Buchanan

Maxwell H. Gluck Equine Research Center Faculty Publications

This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and control of strangles. This updated statement emphasizes varying presentations in the context of existing underlying immunity and carrier states of strangles in the transmission of disease. The statement redefines the “gold standard” for detection of possible infection and reviews the new technologies available in polymerase chain reaction diagnosis and serology and their use in outbreak control and prevention. We reiterate the importance of judicious use of antibiotics in horses with strangles. This updated consensus statement reviews current vaccine technology and the …

Effects Of Benzyl Isothiocyanate And Papain On The Hatching And Migration Of Equine Cyathostomes, Jessie Kmietsch

Undergraduate Honors Thesis Projects

Cyathostomes are widespread and can affect horses of any life stage. Many common anthelmintics are no longer effective at treating cyathostomes due to parasitic resistance. The objective of this in vitrostudy was to use egg hatch and larval migration tests to determine if compounds found in papaya seeds (papain or benzyl isothiocyanate) reduce cyathostome egg hatching and migration. The experiments were conducted between August 2016 and March 2018. Cyathostome eggs were obtained from horse fecal samples. Egg hatch tests were performed by adding papain and benzyl isothiocyanate (BITC) to wells separately at different concentrations in triplicate. After incubation, the …

An Epidemiologic Study Of Antimicrobial Resistance Of Staphylococcus Species Isolated From Equine Samples Submitted To A Diagnostic Laboratory, Ronita Adams, Jackie Smith, Stephan Locke, Erica Phillips, Erdal Erol, Craig N. Carter, Agricola Odoi

Veterinary Science Faculty Publications

Background

Antimicrobial resistance limits traditional treatment options and increases costs. It is therefore important to estimate the magnitude of the problem so as to provide empirical data to guide control efforts. The aim of this study was to investigate the burden and patterns of antimicrobial resistance (AMR) among equine Staphylococcus samples submitted to the University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) from 1993 to 2009. Retrospective data of 1711 equine Staphylococcus samples submitted to the UKVDL during the time period 1993 to 2009 were included in the study. Antimicrobial susceptibility testing, that included 16 drugs, were performed using cultures followed …

Phylogenetic Analysis And Characterization Of A Sporadic Isolate Of Equine Influenza A H3n8 From An Unvaccinated Horse In 2015, Chithra C. Sreenivasan, Sunayana S. Jandhyala, Sisi Luo, Ben M. Hause, Milton Thomas, David E. B. Knudsen, Pamela Leslie-Steen, Travis Clement, Stephanie E. Reedy, Thomas Chambers, Jane Christopher-Hennings, Eric Nelson, Dan Wang, Radhey S. Kaushik, Feng Li

Maxwell H. Gluck Equine Research Center Faculty Publications

Equine influenza, caused by the H3N8 subtype, is a highly contagious respiratory disease affecting equid populations worldwide and has led to serious epidemics and transboundary pandemics. This study describes the phylogenetic characterization and replication kinetics of recently-isolated H3N8 virus from a nasal swab obtained from a sporadic case of natural infection in an unvaccinated horse from Montana, USA. The nasal swab tested positive for equine influenza by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR). Further, the whole genome sequencing of the virus confirmed that it was the H3N8 subtype and was designated as A/equine/Montana/9564-1/2015 (H3N8). A BLASTn search revealed …

Effects Of Kernel Processing At Harvest Of Brown Midrib Corn Silage On Finishing Performance Of Steers, Lauren A. Ovinge, F. Henry Hilscher, Curtis J. Bittner Bittner, Bradley M. Boyd, John N. Anderson, Galen E. Erickson

Nebraska Beef Cattle Reports

A 2 × 3 factorial finishing study evaluated kernel processing in three corn silage hybrids on finishing performance of yearling steers fed 40% silage. The three hybrids included a control corn silage (CON), a brown midrib (bm3), and a brown midrib with a softer endosperm (bm3-EXP). No interactions were observed between hybrids and kernel processing (P > 0.45). Feeding both bm3 hybrids increased dry matter intake and average daily gain over CON (P < 0.01). Cattle fed bm3-EXP and bm3 had lower feed to gain than CON (P = 0.04), with no differences between the two brown midrib hybrids. Feeding silage that has undergone kernel processing decreased dry matter intake with similar average daily gain, which decreased feed to gain by 2.6% at 40% inclusion compared to non-processed silage (P = 0.10). The improvement in silage is calculated to be 6.5% (2.6/40) when kernel processing was utilized as compared to not kernel processing the corn silage hybrids.

Impact Of Ramaekers Immune Primer On Finishing Beef Cattle Performance And Liver Abscess Rate, Hannah C. Wilson, F. Henry Hilscher, Bradley M. Boyd Boyd, Jim C. Macdonald, Galen E. Erickson

Nebraska Beef Cattle Reports

A feedlot study was conducted comparing a natural feed additive (Ramaekers Immune Primer) to Tylan or nothing on receiving and finishing performance. There were no differences for final BW, ADG, F:G, HCW, marbling, LM area, or fat thickness due to treatment. Liver abscess incidence and severity were reduced in steers fed Tylan, no differences were noted between Ramaekers Immune Primer and no additive. There was no difference in number of cattle treated for respiratory illness. Steers on the Ramaekers Immune Primer treatment had lower feed intake during the receiving period but had similar ADG and numerically better F:G at day …

Effect Of Backgrounding System On Performance And Profitability Of Yearling Beef Steers, Cody A. Welchons, Robby G. Bondurant, F. Henry Hilscher Hilscher, Andrea K. Watson, Galen E. Erickson, Jim C. Macdonald

Nebraska Beef Cattle Reports

Five summer management strategies were compared following grazing corn residue through winter. Cattle were assigned to be 1) summer finished, 2) graze bromegrass, 3) graze bromegrass and fed distillers grains at 0.6% of BW, 4) backgrounded in a drylot pen to gain 1.70 lb/d, or 5) backgrounded in a drylot pen to gain 2.35 lb/d. Results differed by year, however, in general as backgrounding ADG increased, days required on feed to reach an equal fat endpoint decreased. In year 1, ADG of cattle grazing bromegrass was less than cattle backgrounded in pens. There was no difference in finishing ADG for …

Effect Of Continuous Or Rotational Grazing On Growing Steer Performance And Land Production, Cody A. Welchons, Robby G. Bondurant, F. Henry Hilscher Hilscher, Terry J. Klopfenstein, Andrea K. Watson, Jim C. Macdonald

Nebraska Beef Cattle Reports

Individual animal performance and animal production per acre were evaluated for steers grazing smooth bromegrass over 2 consecutive years. Treatments consisted of steers continuously grazing smooth bromegrass and initially stocked at either 4.0 animal unit months (AUM)/ac (HI) or 2.8 AUM/ac (LO) or steers rotationally grazing smooth bromegrass and initially stocked at 4.0 AUM/ac (ROT). Average calculated stocking rate for the LO, HI, and ROT treatments was greater than initial stocking rates due to the use of put and take animals. In vitro organic matter digestibility and crude protein of rotationally grazed pastures was relatively constant as the grazing season …

Effects Of Movement And Activity Behavior In A Pasture System Compared To Time, Jace R. Stott, Mitchell B. Stephenson, Kathryn J. Hanford Hanford

Nebraska Beef Cattle Reports

During the summer of 2016 seventeen cows were fitted with Global Positioning System (GPS) tracking collars to evaluate activity characteristics of cattle on rangelands. Data collected included daily distance traveled, average distance from water, daily time spent at water, daily area covered, and percent of day spent active (traveling or grazing). These variables were analyzed weekly to assess changes in behavior as time within pastures increased during three time periods of the growing season. Based on data collected from mid-May to mid-September, cattle showed little changes throughout the grazing season as to levels of activity through different periods of a …

Statistics Used In The Nebraska Beef Report And Their Purpose

Nebraska Beef Cattle Reports

The purpose of beef cattle and beef product research at UNL is to provide reference information that represents the various populations (cows, calves, heifers, feeders, carcasses, retail products, etc) of beef production. Obviously, the researcher cannot apply treatments to every member of a population; therefore he/ she must sample the population. The use of statistics allows the researcher and readers of the Nebraska Beef report the opportunity to evaluate separation of random (chance) occurrences and real biological effects of a treatment. Following is a brief description of the major statistics used in the beef report. For a more detailed description …

Impact Of Winter Supplementation Of May Calving Cows And Heifer Development System In Two Different Breeding Seasons On Subsequent Growth And Reproduction, Shelby A. Springman, Alicia C. Lansford, Jacqueline A. Musgrave Musgrave, John Nollette, Andy Applegarth, Richard N. Funston

Nebraska Beef Cattle Reports

In Exp. 1, May-calving cows were utilized to evaluate the effects of winter supplementation on heifer progeny. Cows grazed either dormant upland winter range with or without a protein supplement or grazed dormant meadow with or without a protein supplement. In Exp. 2, replacement heifers from March and May calving herds were offered ad libitum meadow hay and 4 lb/d supplement or grazed meadow and offered 1 lb/d supplement from mid-January to mid-April. Calf weaning BW and ADG from birth to weaning was less for calves from cows grazing winter range with no supplement compared with all other dam treatments. …

Effect Of Injectable Trace Mineral On Reproductive Performance In Beef Heifers, Shelby A. Springman, John Maddux, Mary E. Drewnoski Drewnoski, Richard N. Funston

Nebraska Beef Cattle Reports

Trace minerals serve an essential role in regulating reproduction. Free-choice trace mineral supplementation is often provided to grazing beef cattle. An injectable trace-mineral solution used with free-choice trace minerals may be beneficial before breeding to improve mineral status. Therefore, Red Angus-based, May-born heifers were utilized to determine the effects of an injectable trace mineral on reproductive performance. Pregnancy rates did not differ between heifers injected with a trace mineral and heifers that received no injection. Injectable trace mineral at CIDR insertion 33 d before artificial insemination did not influence reproductive performance in heifers with adequate trace mineral status.

Evaluating Methods Of Estimating Forage Intake By Grazing Cattle, Aaron J. Shropshire, Walter H. Schacht, Jerry D. Volesky Volesky

Nebraska Beef Cattle Reports

Two methods of estimating forage intake of grazing cattle were compared to clipped estimates in 4-pasture rotational grazing systems on Sandhills subirrigated meadow from mid-May through early August over a 4-year period. Clipping standing vegetation samples within a pasture before and after cattle grazing provides for an accurate estimate of forage removal during a grazing period. A less laborious method of intake estimation commonly used is based on a percentage of an animal’s liveweight. University Extension and some federal agencies use a 2.3% factor and others such as the Natural Resources Conservation Service use a 2.7% factor. In this study …

Letrozole: A Steroid-Free Estrous Synchronization Method, Sarah M. Romereim, Sarah C. Tenley, Mohamed A. Abedal-Majed Majed, Jeffrey W. Bergman, Scott G. Kurz, John S. Davis, Jennifer R. Wood, Andrea S. Cupp

Nebraska Beef Cattle Reports

Most bovine estrous synchronization protocols utilize progesterone plus estrogen to control ovulation timing. A drug that inhibits estrogen production (Letrozole) may be an alternative, steroid-free synchronization method (not yet commercially available). However, low estrogen can negatively affect the health of follicles/oocytes and impact fertility. To determine its effects, Letrozole was administered intramuscularly while tracking follicle growth and circulating hormones. Letrozole response was variable. Two of three cows experienced delayed luteolysis/ovulation and extended progesterone production. This preliminary data indicates that Letrozole treatment allows normal follicle progression but drug response may vary and little is known about effects on oocyte quality.

Impact Of Dietary Fat Source On Beef Display Life, Felipe A. Ribeiro, Katherine I. Domenech-Perez, Emery K. Wilkerson Wilkerson, Hope Voegele, Nicolas J. Herrera, Kellen B. Hart, Chris R. Calkins

Nebraska Beef Cattle Reports

This study was conducted to evaluate the effects of dietary fat source with modified distillers grains plus solubles (MDGS) on beef display life. Steers were fed either a corn control, full-fat MDGS, de-oiled MDGS, or de-oiled MDGS plus corn oil diet. Strip loins were aged for 2, 9, 16 and 23 days and placed under retail conditions for 7 days. Results suggest that feeding MDGS to cattle increases polyunsaturated fatty acid content of beef and has the potential to reduce beef color and lipid stability in comparison to corn diets. These data indicate that feeding MDGS to cattle may decrease …

Using A Cured Meat Model System To Investigate Factors That Influence Cured Color Development, Jennifer A. Posthuma, Faith D. Rasmussen, Gary A. Sullivan Sullivan

Nebraska Beef Cattle Reports

Producing cured meats manufactured with natural ingredients could impact cured meat characteristics, including color. The objective of this study was to determine the effects of nitrite source (sodium nitrite or cultured celery juice powder), reducing agents (no reducing compound or sodium erythorbate/ ascorbic acid), and holding times prior to cooking on cured color development in a meat model system. The addition of reducing compounds had the largest impact on cured color development and reduced residual nitrite in a cured meat model system. Treatments cured with sodium nitrite had slightly greater cured color development than treatments cured with celery juice powder. …

Repeated Calm Handling Can Lead To More Docile Cattle, Jamie T. Parham, Amy E. Tanner, Mark L. Wahlberg Wahlberg, W. S. Swecker Jr., Ronald M. Lewis

Nebraska Beef Cattle Reports

Changes in temperament in heifers when handled either frequently or infrequently were evaluated subjectively based on their behavior when restrained in (chute score) and exiting from (exit score) a squeeze chute. Chute scores decreased over time–a favorable direction–with more dramatic declines in heifers handled more frequently. Heifers with higher chute scores on the first day of handling had the largest reduction in score. Exit scores changed less over time. Chute score therefore may be more indicative of acclimation to a novel environment than exit score. Both scores appear to offer a fast, easy and inexpensive way to quantify docility in …

Rumen Undegradable Protein Content And Digestibility Of Corn Silage And High-Moisture Corn, Colton R. Oney, Jana L. Gramkow, F. Henry Hilscher Hilscher, Elizabeth Schumacher, Andrea K. Watson, Galen E. Erickson, Jim C. Macdonald, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Two studies were conducted to determine rumen undegradable protein (RUP) content and digestibility in corn silage. In Exp. 1, 37 and 42% DM corn silage were incubated in situ with two ruminally and one duodenally cannulated steer to calculate RUP content and RUP digestibility. In Exp. 2, dry rolled corn was reconstituted to 75, 70, 65, and 50% DM and ensiled in mini silos for 30, 90, 180, or 270 days. After ensiling, samples were ruminally incubated to determine RUP content of the grain. The grain within corn silage is less than 50% DM, as moisture content increases and time …

The Effect Of Inoculants On Nutrient Losses Of Corn Silage And High-Moisture Corn Stored In Mini Silos, Colton R. Oney, Jana L. Gramkow, Andrea K. Watson Watson, Galen E. Erickson, Jim C. Macdonald, M. K. Biddlecome

Nebraska Beef Cattle Reports

Two experiments were conducted to determine the effects of inoculants (BONSILAGE CORN 200G and BONSILAGE HMC 200G) containing Lactobacillus buchneri, Lactobacillus plantarum and Pediococcus acidilactici on nutrient losses and aerobic stability of corn silage and high moisture corn. Corn silage and high moisture corn were inoculated and stored in mini silos with nutrient loss and spoilage characterizations at 30, 90, and 120 days with multiple inoculation levels. Longer ensiling times led to greater total acid production. The higher levels of inoculation led to lower total acid production and higher pH. Inoculating corn silage and high moisture corn also affected …

Effect Of Revalor-Xr And Revalor-Xh On Heifer Performance And Carcass Characteristics, Caitlin A. Ohnoutka, Bradley M. Boyd, F. Henry Hilscher Hilscher, Grant I. Crawford, Brandon L. Nuttleman, Galen E. Erickson

Nebraska Beef Cattle Reports

A feedlot study evaluated the effects of 4 implant strategies (Revalor-XR on day 1, Revalor-XH on day 1, Revalor-200 on day 1, and Revalor-200 on day 70) on growth performance and carcass characteristics of feedlot heifers compared to non-implanted heifers fed 198 days. Intake was not impacted by treatments. Implanted cattle had greater carcass-adjusted ADG and lower F:G compared to cattle that received no implant. Implanted treatments had significantly greater HCW, dressing percentages, and lower marbling scores compared to non-implanted cattle. Heifers implanted with Revalor-XR, Revalor-XH, and Revalor-200 on day 70 had larger LM area resulting in lower calculated yield …

Late Summer Planted Oat-Brassica Forage Quality Changes During Winter Grazing, Mary E. Lenz, Jordan L. Cox, Kristin E. Hales Hales, Hannah C. Wilson, Mary E. Drewnoski

Nebraska Beef Cattle Reports

Oat, radish, and turnip samples were taken on pivots being grazed from November through January in Clay Center, Nebraska. The objective was to determine how the quality changed throughout the winter. The forage was observed to be high-quality (highly digestibility with moderate CP content). Digestibility did decline over this period but minimal changes in CP content were observed. From early November to early January, the digestibility of oats appeared to decline more (10% unit decline) than turnip and radish leaves (5% unit decrease). However, digestibility (67% IVOMD) and CP content (15%) of oats in early January were still as high …

Comparison Of Two Alternate Prostaglandin Products In Yearling Beef Heifers, Alicia C. Lansford, Tonya L. Meyer, Richard N. Funston Funston

Nebraska Beef Cattle Reports

Yearling heifers were administered 1 of 2 alternate prostaglandin products (Lutalyse vs. Lutalyse HighCon), which differ in concentration of active ingredient and administration route. Timing of estrus, pregnancy rate to AI, and final pregnancy rate did not differ between treatments. Body weight and ADG were also not affected by prostaglandin treatment. These results indicate producers can utilize Lutalyse HighCon, administered subcutaneously (s.c.), to avoid injection site blemishes and reduce carcass discounts with no impact on estrus synchronization or pregnancy rates.