Animal Sciences Commons^™

Beef Production Systems In The Nebraska Sandhills, Mckay Reed Erickson

Department of Animal Science: Dissertations, Theses, and Student Research

Four studies were conducted to determine the effectiveness of improving production systems of beef cattle in the Sandhills region of Nebraska. These studies were to determine impacts of modified estrus synchronization protocols, genomic testing heifer calves for longevity, and evaluation of 2 differing calving systems (March or May) for improving biological outcome and improved production. Experiment 1 utilized 180 yearling heifers to determine the effectiveness of a second dose of prostaglandin F_2α(PGF) with those females not expressing estrus after an initial 14 d MGA-PG estrus synchronization protocol. The treatment of PGF did increase estrus expression, but did not …

Evaluation Of Microbial Community Dynamics Impacting The Shelf-Life Of Processed Meats, Chad G. Bower

Department of Animal Science: Dissertations, Theses, and Student Research

The objective of this study in its entirety was to utilize high next-generation genetic sequencing to evaluate the microbial communities involved with processed meat spoilage. High throughput 16S rRNA gene sequencing on the Illumina MiSeq© platform was used alongside traditional plating methods to characterize the growth and composition of bacterial communities in processed meats. Previous results from this lab indicated a relatively high prevalence of Pseudomonas in cooked, sliced, and vacuum packaged deli meats, which was contrary to conventional wisdom. Therefore, four studies were designed to further evaluate the factors that may influence microbial communities in processed meats. Study 1 …

Evaluation Of Protein Utilization In Low And High Protein Forage Sources And The Economic Value Of Supplementing Field Peas (Pisum Sativum) To Growing Cattle Grazing Crested Wheatgrass Pastures, Braden C. Troyer

Department of Animal Science: Dissertations, Theses, and Student Research

Field peas are widely grown in the panhandle of Nebraska; however, markets quickly become saturated. A two year experiment was conducted comparing field peas to dry distillers grains with solubles (DDGS) as a protein supplement. The objective was to establish a price producers could pay for field peas relative to DDGS. There was a significant difference in ADG due to type of supplement (P = 0.02). Field pea supplemented heifers had 10% lower ADG compared to DDGS supplemented heifers. Economically, this means if DDGS is priced at or $124.58/ 909 kg DM a producer could pay $2.89/27 kg, for …

The Utilization Of Brown Midrib Corn Silage Hybrids And Kernel Processing To Improve Corn Silage Value And The Use Of High Protein Distillers' Grains To Evaluate Starch Digestion, Lauren A. Ovinge

Department of Animal Science: Dissertations, Theses, and Student Research

Three studies evaluated the effects of corn silage hybrid, inclusion level and kernel processing in growing and finishing diets. Two more studies were conducted on high protein dried distillers' grains and its effect in finishing diets. Experiment 1 and 2 evaluated three corn silage hybrids; standard (CON; hybrid-TMF2H708), brown midrib (bm3; hybrid-F15579S2) and Unified™ brown midrib with SilaSoft™ kernel technology with a floury endosperm (bm3-soft; hybrid-F15578XT) harvested with or without kernel processing on growth and metabolism. Experiment 3 evaluated a brown midrib hybrid (bm3; hybrid-F27F627; Mycogen® Seeds) or a control (CON; hybrid-TMF2H708) in the diet …

Selective Harvest Methods And Chemical Treatment Of Baled Corn Residue For Utilization In Growing Calf And Dry Cow Diets, Ashley C. Conway

Department of Animal Science: Dissertations, Theses, and Student Research

Three studies were conducted to evaluate baled corn residue using selective harvest method and anhydrous ammonia treatments to assess utility in growing calf and dry cow diets. Baled corn residue was harvested using conventional rake-and-bale (CONV) method, or harvested using the New Holland Cornrower in which either eight rows (8ROW), or two rows (2ROW) of corn stalks were chopped into the windrow with tailings. Bales were either not treated or ammoniated at 5.5% DM. When fed to wether lambs in a mixed ration (65% residue, 30% wet corn gluten feed) to determine digestibility, the 2ROW residue had greater apparent DM, …

The Effects Of Butyric Acid On Performance Parameters, Egg Quality And Nutrient Utilization In Young White Leghorn Hens, Dani-El Ruth Hanna

Department of Animal Science: Dissertations, Theses, and Student Research

The objective of this study was to evaluate the effects of Prophorce butyric acid on the performance of White Leghorn laying hens. Hens (180) were placed in 60 conventional cages (3 hens/cage) using a completely randomized design with 30 replicate cages per treatment allowing 722.58cm²/hen. Hens were given the control or butyric acid. The trial spanned 40 weeks (35 weeks old at the start). Water was given ad libitum and hens were fed 110g/day. Egg production and mortality were recorded daily. Egg shell strength, weight, and mass were recorded biweekly; hen weights and egg components were measured monthly; …

The Role Of Inflammatory Pathways In Development, Growth, And Metabolism Of Skeletal Muscle In Iugr Offspring: Blood Gene Expression Of Inflammatory Factors As Novel Biomarkers For Assessing Stress And Wellbeing In Exotic Species, Robert J. Posont

Department of Animal Science: Dissertations, Theses, and Student Research

Our first study identified the effects of maternal inflammation-induced intrauterine growth restriction (MI-IUGR) on growth and muscle glucose metabolism in offspring supplemented with curcumin. MI-IUGR lambs exhibited asymmetric growth restriction at birth and 30d of age, but normal glucose-stimulated insulin secretion. Hindlimb glucose oxidation was reduced by MI-IUGR and not improved by curcumin supplementation. Ex vivo muscle glucose oxidation was reduced by MI-IUGR but improved somewhat by curcumin. These finding indicate that fetal programming responses to MI contribute to neonatal growth and metabolic deficits. Neonatal curcumin supplementation had minimal effect on growth deficits but may improve glucose metabolism. …

Attainment And Maintenance Of Pubertal Cyclicity May Predict High A4 Cows With Reduced Fertility, Sarah Nafziger

Department of Animal Science: Dissertations, Theses, and Student Research

Puberty attainment was investigated in heifers. Blood samples were collected from weaning until breeding during 6 years from heifers born in 2012-2017. Plasma progesterone concentrations ≥ 1 ng/ml were used to indicate cyclicity, and heifers were categorized into one of four puberty groups using SAS: 1) Early heifers reached puberty before March 12 and cycled continuously during the sampling period, 2) Typical heifers reached puberty on or after March 12 and cycled continuously, 3) Start-Stop heifers had at least one occurrence of progesterone ≥ 1 ng/ml but discontinued cycling during the sampling period, and 4) Non-Cycling heifers had no occurrence …

Assessing The Effects Of Genetic Selection For Porcine Circovirus Type 2 Resistance Or Feed Additives On Nursery And Grow-Finish Pig Performance, Dana Michael Van Sambeek

Department of Animal Science: Dissertations, Theses, and Student Research

The swine industry is ever evolving as it strives to produce healthy, wholesome pork for consumers. As such, the industry is constantly looking for ways to improve production and reduce costs. This includes using novel feed ingredients to reduce cost and improve animal health, genetic selection for increased performance, and vaccines to attenuate or prevent illness. Research plays a significant role in assessing the effectiveness of these strategies. Overall, the objective of this thesis was to assess how genetic selection, vaccines, and feed additives may impact growth performance, health, nutrient digestibility, and the microbiome.

In Chapter 2, pigs were either …

Impact Of Ethanol Process Changes On Distillers’ Grains For Beef Cattle, Shelby A. Garland

Department of Animal Science: Dissertations, Theses, and Student Research

Distillers grains plus solubles (DGS) have been widely utilized in beef cattle diets. Fractionation of the corn kernel pre- and post-fermentation has changed the composition of DGS and allowed for the production of other feed byproducts over time. The use of fractionated DGS and other feed byproducts from the ethanol industry has not been heavily researched in beef cattle diets. Three experiments were conducted to evaluate the effect of feeding high protein distillers grains (HiPro DDG) and corn bran plus solubles (Bran + Solubles) in beef cattle diets. Experiment 1 evaluated the effect of byproduct type on finishing performance and …

Quality Effects On Beef From Cattle Fed High-Protein Corn Distillers' Grains Or Other Ethanol By-Products, Kellen B. Hart

Department of Animal Science: Dissertations, Theses, and Student Research

The objective of this study was to evaluate the effects of feeding high protein corn distillers grains on fresh beef quality. Steers (n = 300) were fed one of five diets (6 pens with 10 head/pen): a corn control, 40% high protein dry distillers grains plus solubles (HP-DDGS), 40% dry distillers grains plus solubles (DDGS), 40% wet distillers grains plus solubles (WDGS), or 40% bran plus solubles (Bran). Eighteen Choice carcasses (3 head/pen) were randomly selected within each treatment (n = 88). Strip loins were aged for 2, 9, or 23 d, after which steaks were placed under …

Risk Of Nitrate Toxicity When Grazing Annual Forages, Mary E. Lenz

Department of Animal Science: Dissertations, Theses, and Student Research

Annual forages provide a valuable grazing resource for producers; however, annuals are prone to accumulating nitrate and toxicity can be a potential challenge. There are multiple publications regarding nitrate toxicity, but few, if any, address grazing high nitrate forages. There is variability on what amount of nitrate is considered toxic to cattle, and information is not available on the frequency producers experience toxicity when feeding annual forages. To understand the incidence of nitrate toxicity in the North Central Region of the U.S., a survey was distributed through the “UNL BeefWatch” newsletter to producers. Though producers appeared concerned about nitrates in …

Surveillance And Evaluation Of Manure Treatment Practices For Mitigation Of The Porcine Epidemic Diarrhea Virus (Pedv) In A Commercial Swine Farm Setting, Erin Boyles

Department of Animal Science: Dissertations, Theses, and Student Research

The emergence of the porcine epidemic diarrhea virus (PEDv) in the United States in 2013 resulted in billions of dollars in annual losses for the U.S. swine industry. Infection with PEDv causes severe diarrhea and vomiting in pigs, spreads rapidly through ingestion of infected manure, and produces nearly 100% mortality in pre-weaned piglets. Because swine manure slurry is a valuable crop nutrient source, concerns about virus persistence in stored manure remain a major barrier to proper manure management. Proper manure handling and application practices are necessary to control the risk of pathogen re-infection at affected production sites or infecting new …

Evaluation Of Growth Promoting Implant Strategies And Days On Feed On Finishing Heifer Performance And Evaluation Of Optimal Reimplant Times For Finishing Heifers And Steers, Caitlin A. Ohnoutka

Department of Animal Science: Dissertations, Theses, and Student Research

Two experiments evaluated the effects of delayed, long-acting coated implants or uncoated implants to non-implanted heifers fed for constant or varying days on feed. In Exp. 1, heifers were implanted with either Revalor-XH on d 1, Revalor-200 on d 1, Revalor-XR on d 1, or Revalor-200 on d 70 compared to non-implanted control heifers when fed for an average of 198 d. In Exp. 2, heifers were implanted with Revalor-200 on d 1 and reimplanted with Revalor-200 on d 100, Revalor-XH on d 1, or not implanted and fed for different days on feed: 151, 165, 179, or 193. Implanting …

Effect Of Corn Silage Harvest, Hybrid, And Concentration On Performance In Growing And Finishing Beef Cattle, Fred H. Hilscher Jr.

Department of Animal Science: Dissertations, Theses, and Student Research

Six studies were conducted to evaluate effects of corn silage harvest, hybrid, and concentration in growing and finishing diets. Experiment 1, evaluated corn silage DM (37 or 43%) and replacing corn grain with silage (15 or 45% of diet DM) in finishing diets. Experiment 2, evaluated corn silage DM (37 or 43%) and response to rumen undegradable protein (RUP) supplementation in growing diets. Experiment 3, evaluated nutrient digestibility of 37 or 43% DM corn silage at two different intakes. Experiment 4, 5, and 6 evaluated three corn silage hybrids: a standard hybrid control (CON), a brown midrib (bm3) …

Utilization Of Depth-Enabled Identification And Tracking System To Identify And Track Individual Pigs And Analyse Individual Pig Activity, Jessica Michelle Lancaster

Department of Animal Science: Dissertations, Theses, and Student Research

Ensuring the health and wellbeing of pigs is of the utmost importance to the swine industry. There is a need for a real-time system that can identify changes in pig activities and activity patterns to accurately identify compromised pigs. The value of a real-time system is the capability to identify compromised pigs prior to observance of visible clinical symptoms by facility personnel. Therefore, a novel computer vision depth-enabled identification and tracking (DeIT) system was evaluated. Evaluation of 10,544 randomly selected frames indicated a 93.9% accuracy rate for identifying pigs’ identity when classified by the system as standing/walking. The accuracy of …

Impact Of Shade On Performance And Heat Stress Of Finishing Cattle And Pooled Analysis Of Individually Fed Finishing Trials, Brett A. Melton

Department of Animal Science: Dissertations, Theses, and Student Research

A commercial feedyard trial in Eastern Nebraska evaluated the effect of shade vs no shade on cattle performance, ear temperature, and panting scores. No differences in overall performance (final BW, DMI, ADG, and G:F) or carcass characteristics (HCW, 12^th rib fat thickness, marbling, LM area, and calculated YG) were observed. Cattle that were provided shade had lower panting scores and ear temperatures, and greater DMI, compared to cattle that had no shade during heat events. Also, a treatment by hour interaction for movement of cattle occurred for one of the heat events. In comparison, the cool event had greater …

Identifying Breed Effects For Cow Mature Weight, Madeline J. Zimmermann

Department of Animal Science: Dissertations, Theses, and Student Research

Mature weight (MWT) in beef cattle has increased over the past 30 yr. In general, larger cows are costlier to maintain than smaller cows, and their profitability depends on their production environment. A wide range of beef production environments exist in the United States. There are also a variety of beef cattle breeds that can be chosen and mated to create a type of cow which will be optimally suited to excel in a given environment. However, there remains a need for tools allowing effective comparison among breeds to facilitate such decision making. Unfortunately, estimated progeny differences ( …

Subjective Measures Of Temperament In Beef Heifers Are Reliable Indicators Of Physiological Stress And Indicate Acclimation To Repeated Handling, Jamie T. Parham

Department of Animal Science: Dissertations, Theses, and Student Research

Associations between excitable temperament and many economically relevant traits have been established. In being heritable, temperament can be augmented through selection. Current methods to evaluate temperament in a production setting include numerous subjective and objective measurements, which some producers may find cumbersome to navigate. Those who utilize these methods may not do so efficiently if selection criteria are not indicative of an animal's response to stress, or initial evaluations are not strong indicators of future temperament. The objectives of this research were to develop a procedure for evaluation of calf behavior, indicative of physiological stress, and then determine whether stress …

Evaluation Of The Interaction Of Beta-Adrenergic Agonists Supplementation And Heat Stress On Growth Performance And Carcass Composition In Feeder Lambs, Lauren Elisabeth Kett

Department of Animal Science: Dissertations, Theses, and Student Research

Forty-nine crossbred feeder lambs (wethers, n = 49; 53.3 ± 3.7 kg BW) were utilized to evaluate the interaction of b - adrenergic agonist (bAA) supplementation and heat stress on growth performance and carcass composition. Utilizing and 3 x 2 factorial design, lambs were randomly assigned to one of three bAA supplementation: 1) Control, CON, 2) Ractopamine Hydrochloride at 40 mg/hd/d, RHCL, and Zilpaterol Hydrochloride at 2.5 mg/hd/d, ZHCL for a period of 20 d and one of two environmental conditions (Thermal Neutral: TN and Heat Stress: HS). The TN environment had a constant thermal heat index (THI) of 16.6°C. …

Comparison Of Traditional And Alternative Ingredients On Meat Curing Reactions Using A Model System, Faith Rasmussen

Department of Animal Science: Dissertations, Theses, and Student Research

Consumer’s negative perception of “chemical-sounding” ingredients has increased the use of alternative ingredients. The objective of this study was to determine the effect traditional (sodium nitrite with or without sodium erythorbate) or alternative (celery juice powder with or without acerola cherry powder) curing systems with different ingoing concentrations of sodium nitrite using model meat solutions. Curing systems with reducing agents developed the most cured meat pigment (p < 0.001). Using more than 50 ppm of nitrite did not further increase cured meat pigment (p < 0.001). Curing systems with reducing agents and 50 ppm or greater nitrite had the least residual nitrite (p < 0.001). Alternative curing systems had the most residual sulfhydryl groups when formulated with 100 ppm or more nitrite (p < 0.001). Treatments with reducing agents had greater residual reducing capacity than treatments without reducing agents (p < 0.001). Both alternative and traditional curing systems develop similar cured meat pigment but differences in the nitrosation of cysteine exist.

Advisor: Gary A. Sullivan

Evaluation Of Alpha Amylase Containing Corn On Finishing Cattle Performance And Digestibility, Melissa L. Jolly-Breithaupt

Department of Animal Science: Dissertations, Theses, and Student Research

One digestion and four finishing trials were conducted to evaluate the effect of a new corn hybrid containing an α-amylase trait, Syngenta Enogen Feed Corn (SYT-EFC) on site and extent of digestion, ruminal fermentation parameters, and feedlot performance. Experiments utilized corn containing the enzymatic gene compared to controls, the near isoline parental corn (NEG) or commercially available corn grain (CON), processed as dry-rolled corn (DRC) or high moisture corn (HMC) in diets with dry [distillers grains plus solubles (DGS)] or wet (Sweet Bran) milling byproducts. The corn grain of the experimental diets were fed as the sole grain source, comprising …

Corn Residue Grazing As A Component Of Semi-Confined Cow–Calf Production And The Effects Of Post-Weaning Management On Feedlot Performance, Shelby E. Gardine

Department of Animal Science: Dissertations, Theses, and Student Research

Grazing corn residue can be a valuable alternative to harvested winter feed in a cow-calf production enterprise. The objectives of the first study were to: 1) determine the sample size needed to accurately estimate yield of corn grain and residue and 2) evaluate changes in residue quality throughout the fall/winter and spring-grazing seasons. Results suggest that 6-10 plants serve as a representative sample for grain yield while 7-10 plants are needed for a representative sample of residue yield. In vitro OM digestibility was greatest at the beginning of the fall and spring grazing seasons and declined over time (P < 0.01). In vitro …