Large or Food Animal and Equine Medicine Commons^™

Biology And Detection Of Pregnanes During Late Gestation In The Mare, Michelle Arelia Ann Wynn

Theses and Dissertations--Veterinary Science

Progesterone in the mare declines to almost undetectable concentrations in late gestation. It’s metabolized into several pregnanes, some circulating at very high concentrations. Although the function of many pregnanes remains unclear, 5α-dihydroprogesterone and allopregnanolone are bioactive. Measurements of pregnanes in late gestation are typically by immunoassay, although results are confounded by cross-reactivity with related pregnanes. Conversely, liquid chromatography tandem mass spectrometry (LC-MS/MS) allows differentiation of individual pregnanes. The purposes of these studies were: 1) to evaluate the ability of a 5α-reductase inhibitor, dutasteride, to alter pregnane metabolism and pregnancy outcome, 2) to evaluate changes in target pregnanes in late gestation …

An Investigation Into Specific Seminal Plasma Proteins And Their Effect On The Innate Immune Response To Breeding In The Mare, Carleigh Elizabeth Fedorka

Theses and Dissertations--Veterinary Science

The mare experiences a transient innate immune response to breeding, the resolution of which is crucial for optimal fertility. The majority of mares are able to modulate this inflammation in a timely fashion, but a subpopulation exists which fail to do so and are considered susceptible to persistent breeding-induced endometritis (PBIE). Seminal plasma has been shown to modulate aspects of this inflammation. Recently, two seminal plasma proteins have garnered interest for their immune modulating properties: cysteine-rich secretory protein-3 (CRISP-3) and lactoferrin. These proteins have been found to alter the binding between sperm and neutrophils based on sperm viability in vitro …

Analysis Of Humoral Immune Responses In Horses With Equine Protozoal Myeloencephalitis, Catherine-Jane Angwin

Theses and Dissertations--Veterinary Science

Equine protozoal myeloencephalitis (EPM), caused by the protozoan parasite Sarcocystis neurona, is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1% of infected horses. Factors governing the occurrence and severity of EPM are largely unknown, although horse immunity might play an important role in clinical outcome. We hypothesize that EPM occurs due to an aberrant immune response, which will be discernable in the equine IgG subisotypes a, b, and (T) that recognize S. neurona in infected diseased horses versus …

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, …

Effect Of Harvest Method And Ammoniation On Digestibility And Intake Of Corn Residue, Ashley C. Conway, Tasha M. King, Melissa L. Jolly-Breithaupt Breithaupt, Jim C. Macdonald, Terry J. Klopfenstein, Mary E. Drewnoski

Nebraska Beef Cattle Reports

The effects of three harvest methods, both with and without ammonia treatment, on the in vivo digestibility and intake of baled corn residue were assessed in a digestion trial with lambs. Treatments included three corn residue harvest methods (conventional rake and bale, New Holland Cornrower™ with eight rows or with two rows of corn stalks chopped into the windrow containing the tailings [leaf, husk and upper stalk] from eight harvested rows) and the effects of ammoniation at 5.5% of DM compared to no ammoniation of the residue. Th e 2- Row baled residue (51.7%) had greater dry matter digestibility than …

Methods To Increase Productivity Of Spring Calving Production Systems In The Nebraska Sandhills, Devin Broadhead, L. A. Stalker, Jacki A. Musgrave Musgrave, Rick N. Funston

Nebraska Beef Cattle Reports

Feeding supplement to cattle grazing dormant winter range increased cow BW and BCS and calf performance, but not pregnancy rate. Using a CIDR to shorten the post-partum interval in a cow herd with existing acceptable reproductive performance did not improve pregnancy rate. Feeding creep feed to calves increased weaning BW but should be considered within the context of a cost/benefit analysis. Additional years of data collection may be necessary to draw definitive conclusions.

Predicting Feedlot Growth Performance Over The Feeding Period Utilizing Steer Age And Body Weight, Curtis J. Bittner, Andrea K. Watson, Jim C. Macdonald Donald, Galen E. Erickson

Nebraska Beef Cattle Reports

A pooled- analysis of UNL feedlot pens examined the effects of steer age and body weight on feedlot growth performance. For data analysis, pens were divided into 3 subclasses based on steer age (calf- fed, short yearling, or long yearling) and, grouped based upon initial body weight (500 to 1200 lb, in 100 lb increments) within each age class. As initial body weight increased, DMI (lb/d) for the whole feeding period increased quadratically in calf-fed steers and increased linearly in short and long yearlings. A quadratic increase in ADG was observed in calf- feds as initial body weight increased. No …

Acknowledgements

Nebraska Beef Cattle Reports

Appreciation is expressed to the following firms, associations, or agencies who provided grant support for research in the beef cattle program.

Agriculture and Food Research Initiative Competitive Grant/ USDA/NIFA Foundation Program: Animal Reproduction

The Beef Checkoff , Centennial, Colo

Cargill Corn Milling, Blair, Neb.

CSIRO, Commonwealth Scientific and Industrial Research Organization, Dickson, ACT, Australia

Elanco Animal Health, Indianapolis, Ind.

Huvepharma Inc. Peachtree City, GA

Dr. Kenneth and Caroline McDonald Eng Foundation San Antonio, Tex.

Lallemand Animal Nutrition. Montreal, Quebec, Canada

Merck Animal Health, Madison, NJ

National Cattlemen’s Beef Association, Centennial, Colo.

Effect Of Harvest Method On Digestibility Of Corn Residue, Tasha M. King, Melissa L. Jolly-Breithaupt, Jana L. Gramkow Gramkow, Terry J. Klopfenstein, Jim C. Macdonald

Nebraska Beef Cattle Reports

Corn residues can be an economical forage source for producers and advanced harvest methods have increased the quality of baled residue. A digestion study was conducted to evaluate the effects of harvest method of corn residues (low- stem, highstem, and conventional) on digestibility in lambs. Samples from total fecal collection were dried 1 of 3 ways to determine effects on digestibility estimates. Corn residue containing low- stem had greatest overall digestibility with high- stem residue being intermediate and conventional harvesting having the lowest digestibility. Drying method had no effect on digestibility estimates.

Comparison Of Titanium® 5 Ph- M Versus Titanium® 5 Plus Nuplura® Ph With The Presence Or Absence Of Monensin On Health And Performance Of Newly Received Feedlot Calves Fed Ramp®, Robert M. Jones, Curtis J. Bittner, F. Henry Hilscher Hilscher, Mallorie F. Wilken, Rick Stock, Galen E. Erickson

Nebraska Beef Cattle Reports

A receiving study was conducted to evaluate the effects of RAMP® with Rumensin® concentration (0 or 25.0 g/ton) given with one of two viral vaccinations (Titanium® 5 PH- M or Titanium® 5 plus NUPLURA® PH) on steer growth performance and morbidity. There were no significant vaccine by diet interactions observed. Neither vaccine treatment nor Rumensin® level affected intake, gain, or feed conversion. Vaccine type did not affect first pull (P = 0.19) or second pull morbidity rates (P = 0.52). These findings suggest that neither vaccine type nor Rumensin® concentration had any effect on steer growth performance or morbidity rate.

Evaluation Of 0 Or 300 Mg Of Optaflexx® On Growth Performance And Carcass Characteristics Of Steers Fed To Different Degrees Of Finish, Robert M. Jones, Curtis J. Bittner, F. Henry Hilscher Hilscher, Mallorie F. Wilken, Galen E. Erickson

Nebraska Beef Cattle Reports

A feedlot study evaluated the effects of ractopamine hydrochloride (Optaflexx®) dosage (0 or 300 mg/steer daily) and days on feed (118, 139, 160, 174 DOF) as a 2 × 3 + 1 factorial (steers fed 174 d were not fed Optaflexx) on performance of big yearlings. No interaction was observed between Optaflexx and days on feed. Feeding Optaflexx improved live final BW, carcass- adjusted ADG, carcass- adjusted feed conversion, and calculated yield grade. Increasing days on feed linearly increased live final BW, carcass-adjusted feed conversion, HCW, dressing percent, and marbling score but not ADG. Furthermore, a quadratic increase in LM …

Corn Residue Quality Throughout The Grazing Season, Shelby E. Gardine, Gavin L. Harsh, Robert G. Bondurant Bondurant, Jana L. Gramkow, Andrea K. Watson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Changes in in vitro organic matter digestibility and digestible organic matter of corn residue were evaluated throughout the fall grazing and spring grazing seasons. In vitro organic matter digestibility and digestible organic matter were greatest at the beginning of fall grazing and declined over time. Slight weathering resulted in lower quality corn residue available at the beginning of spring grazing compared to the beginning of fall grazing. The in vitro organic matter digestibility of available residue declined 21% over the fall grazing season and 51% throughout the spring grazing season. As the availability of nutrients declines over time, adjustments in …

Perceptions Of Crop Consultants And Producers On Grazing Corn Residue In Nebraska, Jordan L. Cox, Kristen M. Ulmer, Manir Rakkar Rakkar, Lisa Franzen-Castle, Humberto Blanco-Canqui, Mary Drewnoski, Jim C. Macdonald, Richard J. Rasby

Nebraska Beef Cattle Reports

A survey was conducted to explore factors influencing corn residue grazing recommendations by crop consultants and producer practices in Nebraska. Approximately 80% of consultants recommended grazing corn residue, while 63% of producers allowed grazing. Of producers who did not graze, about 50% cited concerns related to soil compaction, inconvenience (lack of water, fencing, and land/equipment damage), and lack of access to livestock. Producers who allowed and consultants who recommended grazing were more likely to perceive that grazing residue increased subsequent grain yields. Most consultants (56.0%) and producers (43.8%) reported making decisions in regards to grazing based on their own observation. …

Pooled Gain Analysis Of Steers Grazing Corn Residue And Supplemented With Distillers Grains, Cody A. Welchons, Jim C. Macdonald

Nebraska Beef Cattle Reports

A pooled analysis combined data from three trials in which steer calves grazing corn residue were supplemented with distillers grains at varying amounts as a percent of BW. A regression equation was calculated in order to provide an accurate estimate of gain for calves fed distillers grains at various rates. Steers supplemented with distillers grains in a range from 0.3 to 1.1% of BW (1.5 to 6.5 lb / steer daily) had estimated gains that ranged from 1.07 to 1.94 lb / d. Th is prediction equation provides an estimate of gain for calves supplemented with distillers grains at various …

Effect Of Feeding Field Peas On Fresh Beef Quality, Hope R. Voegele, Katherine I. Domenech, Emery K. Kunze Kunze, Felipe A. Ribeiro, Karla H. Jenkins, Jim C. Macdonald, Chris R. Calkins

Nebraska Beef Cattle Reports

Th is study was conducted over two years to evaluate the use of field peas during two phases of production (grazing and finishing) on overall fresh beef quality. The backgrounding treatments included: no supplement, field peas, or dry- rolled corn and finishing treatments included the presence or absence of field peas. Loin samples (n = 232) were aged for 14 d and placed under retail display conditions for 7 d. Dietary treatments had no effect on tenderness (WBSF or SSF) or visual discoloration and minimal effects on objective color, lipid oxidation and fatty acid composition. These data indicate field peas …

Nutrient Content Of Summer-Planted Oats After Corn Harvest And Grazing Performance, Kristen M. Ulmer, Robert G. Bondurant, Jana L. Gramkow Gramkow, Mary E. Drewnoski, James C. Macdonald

Nebraska Beef Cattle Reports

Annual forages provide producers with an alternative grazing source in the fall. A cover crop grazing study was conducted following corn harvest to evaluate the steer ADG and yield of summer sown oats and turnips planted after either high moisture corn or corn silage production. Th e gain of steers grazing oats aft er silage was 1.29 lb/day, while the gain of steers grazing corn residue and oats aft er high moisture corn was 0.72 lb/day. Average oat forage production aft er silage harvest was 2857 lb/acre, while oat production following corn harvest was 523 lb/ acre. Fall forage production …

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 …

Effect Of Heifer Development System On Reproduction And Subsequent Gain As A Pregnant Heifer, Shelby A. Springman, Hazy Rae Nielson, Tonya L. Meyer, Mike Kirby, Jim Teichert, Richard N. Funston

Nebraska Beef Cattle Reports

Weaned heifers grazed corn residue, upland range, or were fed 1 of 2 drylot diets differing in energy. Heifer development diets did not impact their resulting AI or final pregnancy rates. Cost per pregnant heifer was similar among treatments. A subset of AI- pregnant heifers was placed in a Calan Broadbent individual feeding system during late gestation. As a pregnant heifer, feed efficiency was not impacted by development system. These results indicate producers may utilize their most readily available and/or cost- effective feed resources with no detriment to pregnancy rates or feed efficiency as first- calf heifers.

Effect Of Three Initial Implant Programs With A Common Terminal Revalor®- 200 On Feedlot Performance And Carcass Traits Of Weaned Steers, Colton R. Oney, Galen E. Erickson, Andrea K. Watson Watson, Marshall N. Streeter, Robert J. Cooper, Bill D. Dicke, D. J. Jordon, Tony L. Scott

Nebraska Beef Cattle Reports

A commercial feedlot study utilizing 1,350 calf- fed steers (initial BW = 623 lb; ±23 lb) compared three initial implant strategies: Revalor®- IS (day 1), Revalor®- IS (day 1) and Revalor®- 200 (day 67), or Revalor®- XS (day 1). Each initial implant strategy was followed by a terminal Revalor®- 200 implant (day 133) to determine effects on performance and carcass traits. No differences in final body weight, intake, gain, or feed conversion were observed on either a live, or carcass adjusted basis. Th ere were also no differences in hot carcass weight, USDA quality grade, or USDA yield grade. Results …

The Lowdown Of Out-Of-Competition Testing: What The Rmtc Isn't Telling Us About Its Proposed Regulations, Clara Fenger, Tanya Boulmetis, Kim Brewer, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

No abstract provided.