Veterinary Preventive Medicine, Epidemiology, and Public Health Commons^™

Development Of An Animal Model For Enterovirus For Evaluation D68 For Screening Of Antiviral Therapies, W. Joseph Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enterovirus D68 (EV-D68) virus has become more prevalent over the last 15 to 20 years. EV-D68 attacks the respiratory system and can cause severe disease in individuals who have underlying respiratory problems. There have also been reports of individuals with EV-D68 showing signs of neurological system problems and acute flaccid paralysis. Because of the increase in patients with EV-D68 and also the potential for neurological disease, an animal model is needed to study the disease and to evaluate experimental therapies for EV-D68 infection.

To develop the animal model, 4-week old AG129 mice that lack alpha and beta interferon receptors, making …

Trends In The Environmental Health Job Market For New Graduates, Jason W. Marion, Timothy J. Murphy Phd, Anne Marie Zimeri Phd

EKU Faculty and Staff Scholarship

The question of whether the job market can support future graduates of environmental health programs remains an important and difficult question for environmental health programs, current and prospective students, parents, and other stakeholders. Our previous report using 2014 data from the U.S. Bureau of Labor Statistics demonstrated anticipated growth and higher than average pay in the profession through at least 2022 for baccalaureate degree holders (Marion & Sinde, 2015). Growth in the profession does not necessarily translate into job availability if the market is saturated with job candidates. While university programs produce graduates, local health departments (LHDs) have suffered tremendous …

Trap-Neuter-Return Programs And The Importance Of Associated Public Awareness, Nicolette Sliwa

Biology: Student Scholarship & Creative Works

The focus of this paper is to describe a typical Trap-Neuter-Return (TNR) program and highlight the major pros and cons surrounding this somewhat controversial method of managing the overwhelming free-roaming cat population. The effects of the species’ overabundance on the environment and human health are also discussed. Citing studies completed on TNR programs around the globe as well as mathematical models, the effectiveness of this method is compared to other, currently used alternatives. Finally, it has been suggested that the general awareness level a neighborhood possesses about the true goals of TNR programs has a potentially significant impact on the …

Israel : Translocation Of Rabies, Sarah Baker

Global Public Health

Israel is now faced with a steady growing public health threat as canine rabies has reemerged in the northern region of Israel. While the steady increase in cases is of notable alarm, moreover the close contact most often shared between dog and human populations is of much more concern from a public health prospective. Rabies is a vaccine-preventable disease. Vaccinating dogs has proven to be the most cost-effective strategy for preventing rabies in people. Additionally, education on bite prevention and rabid animal behaviors for both children and adults is an essential extension of the long term rabies vaccination program that …

Relationship Between Dietary Total Digestible Nutrients And Digestible Organic Matter In Beef Cattle Finishing And Growing Diets With Or Without Distillers Grains, Hannah C. Hamilton, Jana L. Gramkow, Jim C. Macdonald Donald, Galen E. Erickson, Andrea K. Watson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

The relationship between organic matter digestibility and total digestible nutrients is unestablished for diets containing distillers grains. Three cattle digestion studies were used to evaluate the relationship between total digestible nutrients and digestible organic matter. Results suggest digestible organic matter is consistent relative to total digestible nutrients content for traditional, corn based diets. In finishing and growing diets containing distillers grains additional digestible energy supplied by distillers grains is not accounted for when evaluating only digestible organic matter. Measuring digestible energy content of diets used in digestion trials is essential.

Evaluation Of The Value Of Fiber In Distillers Grains Plus Solubles On Performance Of Finishing Cattle, Jordan E. Burhoop, Liesel J. Schneider, Curtis J. Bittner Bittner, F. Henry Hilscher, Jim C. Macdonald, Rodney A. Moxley, David R. Smith, Galen E. Erickson

Nebraska Beef Cattle Reports

A finishing study was conducted to determine the value of the fiber in distillers grains plus solubles on cattle performance. Five treatments were evaluated: a corn control diet, 20 or 40% modified distillers grains plus solubles, plus two diets containing corn germ meal and corn bran balanced to equal the fiber content of the two modified distillers grains plus solubles diets. Th ere was a significant improvement in ADG and F:G for cattle fed modified distillers grains plus solubles compared to control. Cattle fed the corn germ meal and bran diets had increased DMI, slightly lower ADG, and poorer F:G …

The Effect Of Supplementing Mannan Oligosaccharide Or Finely Ground Fiber, During The Summer On Body Temperature, Performance, And Blood Metabolites Of Finishing Steers, Bradley M. Boyd, Terry L. Mader, Curtis J. Bittner Bittner, Henry Hilscher, Gene Wijffels, John B. Gaughan, Megan Sullivan, Judy Cawdell- Smith, Galen E. Erickson

Nebraska Beef Cattle Reports

Crossbred beef steers (12 pens, n=96) were used to determine the effect of adding Agrimos or 5% ground (1 in.) wheat straw compared to a control on body temperature, panting score and performance. Th ere were no differences in final BW, ADG, and DMI among treatments. Feed conversion was increased for cattle fed 5% additional ground straw when compared to control and Agrimos. Hot carcass weight, dressing %, LM area, and marbling score were not different among treatments. Cattle fed the control had greater 12th rib fat depth and USDA yield grade than cattle fed straw or Agrimos. Both average …

Effect Of Salt Reduction On The Quality And Shelf Life Characteristics Of Deli-Style Roast Beef, Chad G. Bower, Regan E. Stanley, Samodha Fernando Fernando, Gary A. Sullivan

Nebraska Beef Cattle Reports

Concerns with excessive sodium intake have led to increased pressure on meat processors to reduce added salt in meat products. Quality characteristics and microbial growth were evaluated on deli- style roast beef slices formulated to contain varying concentrations of added salt. Salt concentration had no effect on microbial community composition, however increasing salt slowed microbial growth over time. Increasing salt increased cooking yield and decreased water activity. Salt reduction negatively impacts the texture, yield, and shelf life of deli- style roast beef, however salt concentrations within this range do not significantly alter spoilage flora community composition.

Effect Of Crude Glycerin Concentration On Growing Steer Performance In Forage Diets, Robert G. Bondurant, Galen E. Erickson, Terry J. Klopfenstein Klopfenstein, James C. Macdonald

Nebraska Beef Cattle Reports

The effect of increasing crude glycerin concentration was evaluated in a 91- d growing trial utilizing 60 steers. Crude glycerin was included at 0, 4, 8, and 12% of dietary DM in diets consisting of 50% wheat straw; 22.9- 37.0% wet corn bran, and 8.0- 10.1% soybean meal. Crude glycerin replaced wet corn bran and soybean meal was added to maintain dietary CP. Steer ending BW was not different among treatments. Th ere was a quadratic increase in DMI from 0 to 8% crude glycerin and subsequent decrease at 12%. Th ere was no difference in ADG or feed efficiency …

Development Of Terminal And Maternal Economic Selection Indices In Beefmaster Cattle, Kathleen P. Ochsner, Michael D. Macneil, Ronald M. Lewis, Matthew L. Spangler

Nebraska Beef Cattle Reports

Two economic selection indices were developed for Beefmaster cattle, one for a terminal objective and one for a maternal objective. The terminal index was developed assuming bulls would be mated to mature cows with all resulting progeny harvested. The maternal index was developed assuming bulls would be mated to a combination of heifers and mature cows, with resulting progeny retained as replacements or sold at weaning. Relative economic values for the terminal objective traits hot carcass weight, marbling score, ribeye area, 12th- rib fat and feed intake were 91.29, 17.01, 8.38,- 7.07 and- 29.66, respectively. Relative economic values for the …

Organic Acids And Applications Used For Reduction Of E. Coli On Beef Shoulder Clods Used For Ground Beef, Kelly A. Mccarty, Gary A. Sullivan, Dennis E. Burson Burson

Nebraska Beef Cattle Reports

Small processors normally grind beef shoulder clods for ground beef that have not been previously tested for shiga toxin-producing E. coli. Three antimicrobial solutions were applied using three application methods to beef sub-primals to evaluate the effectiveness of reducing E. coli and the effects on quality attributes. Antimicrobials effectively reduced Rifampicin resistant E. coli. However, none of the treatments changed color attributes or total plate counts compared to a control. These results suggest that an appropriate antimicrobial solution and application method can be selected for use by small meat processors without affecting quality attributes.

The Influence Of Diet And Oxidation On Calcium Retention Of The Mitochondria In Fresh Beef, Emery K. Kunze, Nicolas J. Herrera, Katherine I. Domenech-Perez Perez, Michael D. Chao, Chris R. Calkins

Nebraska Beef Cattle Reports

Feeding dried distillers grains (DG) may influence calcium flux postmortem by disrupting the stability of the sarcoplasmic reticulum (SR) membrane, thus leading to a higher post- rigor calcium leakage, resulting in greater activation of calpains and improved tenderness. Mitochondria provide the opportunity to study calcium flux in a controlled, tightly defined environment as a model system for the SR. Cattle were finished on diets containing either 0% DG or 50% DG. Feeding DG increased proportions of PUFA in the SR and mitochondrial membrane. Oxidized mitochondria retained less calcium than non- oxidized mitochondria. Mitochondria from cattle finished on corn tended to …

Comparison Of Diets Collected From Esophageally Fistulated Cows To Forage Quality Estimated From Fecal Analysis, Bethany M. Johnston, Jay D. Jenkins, Jacqueline A. Musgrave Musgrave, L. A. Stalker, Mitchell B. Stephenson

Nebraska Beef Cattle Reports

Differences in forage quality (crude protein and energy) were analyzed between esophageally fistulated diets, analysis of fecal samples with Nutrition Balance Analyzer (NUTBAL) analysis, and analysis of handclipped forage samples. On upland range sites, hand- clipped samples provided forage quality estimates that were closer to esophageally fistulated diets than samples analyzed with the NUTBAL analysis. Aft er one year of data collection, it appears that there may be some inconstancies with the NUTBAL analysis for estimates on rangeland forage quality in the Nebraska Sandhills. More data is needed to verify these results; however, making management supplementations decisions solely on the …

Summer Cocktail Forage Research In The Panhandle Of Nebraska, Karla H. Jenkins, Cody Creech, Robert Higgins Higgins, Josh Buttle

Nebraska Beef Cattle Reports

Four annual forage mixtures containing brown mid- rib sorghum sudangrass or German foxtail millet, cowpeas or soybeans, and forage collards were compared to the sorghum sudangrass or millet as monocultures in the Nebraska High Plains on dryland acres to determine the tonnage, crude protein, and digestibility available for beef cattle. Th e forage mixtures and the millet resulted in greater crude protein than the sorghum sudangrass. Total digestible nutrients of the mixers were similar. Sorghum sudangrass resulted in the most tonnage. These forage options could have been hayed or windrow grazed in the fall and would have likely resulted in …

Impact Of Inoculum Source For In Vitro And In Situ Digestion Procedures Performed On Corn Residue And Grass Samples, Hannah C. Hamilton, Jana L. Harding, Jim C. Macdonald Donald, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

A study was conducted to assess the effects of inoculum source at time of incubation on neutral detergent fiber digestibility, dry matter digestibility, and organic matter digestibility of corn residue samples. Digestibility of neutral detergent fiber was greater for both grass and corn residue when inoculum source came from steers consuming a high corn residue diet. Digestibility of dry matter and organic matter were not different between grass and corn residue. It is not necessary to maintain two sets of donors for in vitro or in situ procedures involving corn residue. However, donor diet affects neutral detergent fiber digestibility estimates …

Evaluation Of Plant- Waxes To Estimate Forage Intake In Grazing Cattle, Hannah C. Hamilton, Jerry D. Volesky, Robert M. Lewis Lewis

Nebraska Beef Cattle Reports

Although key to the efficiency of a cattle operation, feed intake is challenging to evaluate in a grazing setting. However, even within forage- based systems, plant- wax markers may be used to predict dietary choices and feed intake. Plant- waxes are a complex mixture of lipids found on the surface of plants. When sufficiently unique among plants, the composition of diets can be determined from the pattern of these compounds in the forages ingested. These markers were used to delineate the parts of the corn plant and, separately, 8 western rangeland grasses and legumes. Using plant waxes, the components of …

Evaluating The Impacts Of Field Peas In Growing And Finishing Diets On Performance And Carcass Characteristics, Hannah L. Greenwell, Karla Jenkins, Jim C. Macdonald Donald, Matt K. Luebbe

Nebraska Beef Cattle Reports

The impact of field peas as a grazing supplement and a component of finishing diets on performance and carcass characteristics was evaluated over two years. During grazing, cattle supplemented with field peas had a greater ending body weight and average daily gain than cattle that received no supplement. However, cattle supplemented with corn had greater average daily gain than both peas and control cattle. Overall, those cattle not supplemented during grazing compensated 53% and 88% when compared to those cattle supplemented corn and peas, respectively. Inclusion of field peas in grower supplement or finishing diets may be advantageous if appropriately …

Effects Of Field Pea Supplementation On Digestibility And Rumen Volatile Fatty Acid Concentration Of Diets Containing High And Low Quality Forages, Hannah L. Greenwell, Jana L. Gramkow, Melissa L. Jolly-Breithaupt Breithaupt, Jim C. Macdonald, Karla Jenkins

Nebraska Beef Cattle Reports

Five ruminally cannulated steers were used to evaluate the effects of supplementation (no supplement, field peas, or dry rolled corn; 0.43% BW) with high and low quality forages on diet digestibility and rumen volatile fatty acid concentrations. Th e inclusion of field peas increased dry matter intake and organic matter digestibility over dry rolled corn and unsupplemented steers. Propionate proportions were less for field peas and control treatments than dry rolled corn, while acetate proportions increased in field peas, and control treatments as compared to dry rolled corn. As a result, acetate to propionate ratio was reduced when dry rolled …

Effects Of Wintering System On Cow And Calf Performance In A Summer- Calving Intensive Production System, Shelby E. Gardine, Jason M. Warner, Curtis J. Bittner Bittner, Robert G. Bondurant, Karla Jenkins, Richard J. Rasby, Matt K. Luebbe, Galen E. Erickson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

A study evaluated the effects of two wintering systems (cornstalk grazing and drylot feeding) on cow- calf performance in a summer- calving intensively managed cowherd at two locations. Grazing cow- calf pairs on cornstalks resulted in lower ending BW of cows and reduced ADG of calves when compared to drylot cow- calf pairs at weaning. A partial budget of incorporating winter cornstalk grazing into an intensive production system suggests that cows wintered on cornstalks were $136.85 more profitable when compared to cows wintered in the drylot.

Effects Of Modified Distillers Grains And Corn Ratios As Supplements In Diets Varying In Forage Quality On Performance Of Growing Beef Steers, Viviane B. Ferrari, Robert G. Bondurant, Galen E. Erickson Erickson, Terry J. Klopfenstein, Jim C. Macdonald

Nebraska Beef Cattle Reports

Distillers grains (DG) have been intensively used for beef production, but prices relative to corn vary such that it may be beneficial to displace a portion of DG with corn in certain circumstances. Four ratios of supplemental energy (40% of diet DM) from modified distillers grains and corn (100:0, 80:20, 60:40, and 40:60) were supplemented in one of 3 forage diets (56% of diet DM) and evaluated for performance. Forages were high (brome hay + sorghum silage) or low quality. Low quality forages were corn residue baled through conventional rake and bale, or by disengaging the spreader on the combine …

Fatty Acid Composition Of Beef Fed Omnigen- Af At Receiving Or Finishing, Katherine I. Domenech, Michael D. Chao, Joe O. Buntyn Buntyn, Ty B. Schmidt, Chris Calkins

Nebraska Beef Cattle Reports

Beef fatty acid profiles and superoxide dismutase activity were determined for cattle receiving OmniGen- AF supplementation (a patented nutritional supplement) at receiving (first 28 d at the feedlot) or throughout finishing (all 210 d of finishing) vs. a control group (non- supplemented). Th e most meaningful change in fatty acid composition from inclusion of OmniGen- AF was total poly- unsaturated fatty acid (PUFA) content where beef from the finishing group had more PUFA content in relation to the receiving group and was not different from the control group. Despite this increase in PUFA, cattle supplemented through finishing tended to have …

Effect Of Backgrounding System On Steer Performance And Carcass Characteristics, Jordan L. Cox, Kristin E. Hales, Kristen M. Ulmer Ulmer, Richard J. Rasby, Steven D. Shackleford, Chad Engle, John Rieckman, Harvey C. Freetly, Mary Drewnoski

Nebraska Beef Cattle Reports

The impact of 3 backgrounding systems: grazing corn residue with distillers grains supplementation at 0.86% BW/d, grazing an oats-brassica forage, or feeding a grower ration in a drylot on finishing performance and carcass characteristics were evaluated. Backgrounding phase gains were greatest for steers fed a grower ration in the drylot (3.58 lb/d), intermediate for steers grazing oats-brassica forage and then fed the grower ration for short period (2.65 lb/d), and least for steers grazing corn residue while supplemented distillers grains and then fed the grower ration for short period (2.22 lb/d). These backgrounding treatment differences did not affect ADG during …

Shelf Life Of Ground Beef From Cattle Fed Distillers Grains Containing Different Amounts Of Oil, Faith D. Rasmussen, Chad G. Bower, Gary A. Sullivan Sullivan

Nebraska Beef Cattle Reports

Beef shoulder clods were collected from steers fed one of four finishing diets: no distillers grains and three with distillers grains containing different amounts of oil. Raw ground beef patties were evaluated for changes in objective color, discoloration, and lipid oxidation during simulated retail display (7 days). Cooked beef links in refrigerated (18 days) and frozen storage (198 days) were analyzed for lipid oxidation throughout shelf life. Fatty acid profiles were evaluated in lean, subcutaneous fat, and ground composite samples. All distillers grain diets increased C18:2 and polyunsaturated fatty acids in beef. There were no dietary differences in lipid oxidation …

Rumen Undegradable Protein And Bambermycins Supplementation Of Calves Grazing Corn Residue, Cody A. Welchons, Robert G. Bondurant, F. Henry Hilscher Hilscher, Jim C. Macdonald, Galen E. Erickson

Nebraska Beef Cattle Reports

Steer calves grazing non- irrigated corn residue were supplemented with a corn residue and by- product pellet that contained either Soypass, soybean meal, or processed soybean meal at a rate of 4 lb / d. Additionally, a supplement was fed at 1 lb / d that provided 0 or 20 mg / steer daily of bambermycins (Gainpro®). There was no interaction between bambermycins inclusion and pellet type. Likewise, there was no effect of pellet type or bambermycins on ending BW or ADG. In order to maximize gain of calves grazing corn residue it is important to provide a supplement that …

Delineating Complex Forage Mixtures Using Plant-Wax Markers, Napoleón Vargas Jurado, Hannah C. Hamilton, Ronald M. Lewis

Nebraska Beef Cattle Reports

Plant waxes provide a marker profile of individual plants that, when sufficiently distinct, can be used to estimate the diet composition of grazing cattle. They also may provide a tool for reliably predicting feed intake. The traditional method (nonnegative least squares) to use these markers to predict diet composition has limitations. A newer statistical approach (Bayesian linear unmixing) deemed more efficient was tested with simulation. Samples from 8 forage species in Nebraska were analyzed for their plant- wax marker contents. Those concentrations were used to simulate 1000 diets for 4 mixtures containing 2, 3, 5 or 8 plants. The efficiency …

Effect Of Corn Residue Grazing Or Baling On Subsequent Crop Yield And Nutrient Removal, Kristen M. Ulmer, Jordan L. Cox, Manbir K. Rakkar Rakkar, Robert G. Bondurant, Humberto Blanco-Canqui, Mary Drewnoski, Karla H. Jenkins, James C. Macdonald, Rick J. Rasby

Nebraska Beef Cattle Reports

A 2- year study evaluated the effect of corn residue baling or grazing on subsequent yields, as well as, nutrient removal by baling at five locations in Nebraska. Three treatments were applied to each field: baled, grazed, and control (no baling and no grazing). Grain and stover yields were measured by hand harvest at maturity. No differences were observed among treatments for corn yield with baled having yields of 234 bu grain / acre, grazed with 239 bu grain / acre and control with 223 bu grain / acre. Th ere was no difference in stover yield among treatments (8,326, …

Timed Insemination Vs. Modified Estrus Detection In Beef Heifers, Benjamin T. Tibbitts, Tonya L. Meyer, Dan J. Kelly Kelly, Richard N. Funston

Nebraska Beef Cattle Reports

Th e objective of this study was to compare a modified estrus detection and fixed time AI vs. no estrus detection and fixed time AI on subsequent pregnancy rates. Yearling heifers were estrus synchronized and AI at 72 ± 2 h after prostaglandin injection. In one group estrus was not detected and all heifers received gonadotropin releasing hormone at the fixed- time AI; in the other group estrus was detected at 58 ± 2 and 70 ± 2 h after prostaglandin and inseminated in the following order at 72 ± 2 h: heifers in estrus at 58 h, heifers in …

Growth And Reproductive Performance Of Yearling Beef Heifers Implanted With Revalor G In The Nebraska Sandhills, Benjamin T. Tibbitts, Hazy Rae Nielson, K. H. Ramsay Ramsay, Richard N. Funston

Nebraska Beef Cattle Reports

Th is study evaluated effects of a single stocker implant (Revalor G) on growth and reproductive performance of yearling beef heifers in the Nebraska Sandhills. Crossbred heifers, grazing native Sandhills range, were randomly assigned to either be implanted 82 ± 2 days prior to estrus synchronization, or not implanted, to determine the effects of growth implants on heifer performance. Heifers were bred via artificial insemination followed with clean- up bulls. Implanted heifers gained more and were heavier at the end of the trial, but had a reduced pregnancy rate than non- implanted heifers. Implanted heifers also had a lower pregnancy …

Impact Of Heifer Development System In Two Different Breeding Seasons, Shelby A. Springman, Hazy Rae Nielson, Jacqueline A. Musgrave Musgrave, John Nollette, Andy Applegarth, Richard N. Funston

Nebraska Beef Cattle Reports

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. Heifers fed hay gained more during the treatment; however, heifers grazing meadow experienced compensatory gain, resulting in similar body weight at pregnancy diagnosis in both calving herds. Pregnancy rates were similar between treatment groups in March and May heifers. A reduced input winter management system is a viable option to maintain pregnancy rates in early and late summer breeding seasons.

Effects Of Distillers Grains Or Fiber On Enterohemorrhagic Escherichia Coli In Steers, Liesel G. Schneider, Curtis J. Bittner, Jordan E. Burhoop Burhoop, F. Henry Hilscher, Galen E. Erickson, Terry J. Klopfenstein, Rodney A. Moxley, David R. Smith

Nebraska Beef Cattle Reports

Increased probability for fecal shedding and colonization by Escherichia coli O157:H7 has been observed in previous studies when steers are fed increased inclusions of distillers grains. A feeding study was conducted to determine if distillers grains or fiber from distillers grains in the finishing ration of feedlot steers affected fecal shedding prevalence of seven serogroups of enterohemorrhagic Escherichia coli (EHEC- 7). For EHEC O45 and EHEC O103, the greatest prevalence of shedding occurred when steers were fed increased distillers grains For all EHECs except for O111, fecal shedding prevalence was similar between the corn control and either of the corn …