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Methane From Lactating Dairy Cattle: Studies For Mitigation, Diurnal Variation, And Role In Energy Metabolism, Jared Vern Judy

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

Reducing methane production in dairy cattle has received an increased interest due to environmental concerns associated with its potency as a greenhouse gas. Methane represents lost energy in cattle and reduction may increase animal efficiency and productivity. Experiment 1 evaluated strategies of mitigating methane production in lactating dairy cattle with inclusion of dried distillers grains and solubles (DDGS), DDGS with added corn oil, and DDGS with added calcium sulfate and effects on energy and nitrogen balance. Inclusion of DDGS, corn oil, and calcium sulfate, increased DMI and milk yield. Methane production was reduced with addition of corn oil …

Evaluation Of Corn Condensed Distillers Solubles In Beef Cattle Diets And Grazing Double-Cropped Forages Following Corn Harvest, Benjamin H. Hansen

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

Corn condensed distillers solubles (CDS) is a protein and energy dense by-product from dry-milled production of ethanol. Recent oil extraction has posed modifications to the nutrient profile of CDS, suggesting that de-oiled CDS needs to be re-evaluated in beef cattle diets. Three experiments were conducted to evaluate the effects of CDS in high-concentrate diets, forage-based diets, as well as evaluate the effects of CDS on diet digestibility and rumen fermentation parameters in forage-based diets. Feeding CDS in high-concentrate diets up to 20% of the diet DM or in combination with wet distillers grains plus solubles (WDGS) improved performance and resulted …

The Effects Of Feed Additives In Beef Finishing Systems And The Effect Of Rumen Degradable Protein Supplementation In Corn Residue Grazing Systems With The Use Of Distillers On Growth Performance, Robert M. Jones

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

One receiving trial evaluated the effect of the feed additive monensin (trade name: Rumensin) on steer growth performance in the receiving period while evaluating the effects of two receiving vaccinations on morbidity and mortality of newly received calves. No differences were observed in growth performance, morbidity rate or mortality rate between treatments for the first 28 d of receiving. A finishing trial evaluated the effect of the feed additive ractopamine hydrochloride (trade name: Optaflexx) on feedlot growth performance and carcass characteristics of crossbred yearling steers fed to differing degrees of finish. Feeding ractopamine hydrochloride at 300 mg improved ADG, G:F, …

Evaluating Long-Term Direct And Correlated Selection Response In White Plymouth Rock Chickens Selected For High Or Low 8-Week Body Weight, Sylvia Harrison

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

The increasing demand for poultry meat has led animal breeders to engage in artificial selection of chickens as a way to increase the productivity of poultry. Long-term experiments have been designed to measure rates of genetic response to a trait under selection, and correlated traits, as well as gauge possible selection limits.

Two studies were conducted to evaluate response to selection for body weight (BW) in chickens. The chickens were selected for high or low BW at 8 weeks of age. Those that met the criterion were selected as parents for the subsequent generation. In the first study the population …

Effect Of Fat And Fiber On Methane Production And Energy Utilization In Lactating Dairy Cows, Olivia Rose Drehmel

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

Due to rising concerns of greenhouse gases and that ruminants are the largest livestock methane producers, an emphasis has been put on developing methane mitigation strategies to reduce methane emissions in ruminants. Other than reducing methane, maximizing the energy utilization of cattle is also important for producer’s overall productivity and profitability.

In the first experiment, fat or cellulose was added to fiber isolated from dried distiller’s grains and solubles. Isolated NDF residue from an in vitro setting was fermented 1) alone (control); 2) with feed grade corn oil at 20%; or 3) with cellulose powder microcrystalline at 20% using the …

The Effects Of Supplemental Rup In Corn Silage Growing Diets And Rup Digestibility Of Corn Silage, The Utilization Of Aggressive Implant Protocols, And The Effect Of Inoculate On Corn Silage And High Moisture Corn, Colton R. Oney

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

Three experiments evaluated the effect of implant strategies on feedlot performance and carcass characteristics of crossbred steers and Holstein steers. Final BW, ADG, and G:F were not different between implant strategies in Exp. 1 and 2. The utilization of more aggressive implant strategies has minimal impact on both feedlot and carcass performance of cross breed steers.

Four experiments evaluated the effects of supplemental RUP in corn silage growing diets and RUP content and RUP digestibility of corn silage. Exp. 1, supplemented five concentrations of RUP to growing calves consuming a corn silage diet. As supplemental RUP increased ADG and ending …

Metabolic Regulation By Stress Mediators In Fetal Ovine Skeletal Muscle And Adult Bovine Myoblasts, Elena Marie Merrick

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

Our objective was to determine the effect of stress mediators such as inflammatory cytokines and β adrenergic agonists on developing skeletal muscle. Fetal sheep exposed to chronic maternal inflammation had decreased skeletal muscle glucose oxidation rates when stimulated with insulin or TNFα. In addition, activation of Akt by insulin was decreased after maternal inflammation when compared to controls and there were not differences in skeletal muscle fiber type ratios between the two treatment groups. This indicates that maternal inflammation does not affect overall oxidative capacity in the developing fetus, but rather insulin signaling pathways are disrupted.

We sought to determine …

Evaluation Of Distillers Grains Components For Finishing Beef Cattle, Jordan E. Burhoop

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

With the large expansion of the ethanol industry in previous years, there has been an increase in supply of distillers grains plus solubles (DGS) for the feedlot industry. Distiller’s grains are a common byproduct used in feedlot diets for added protein or energy. Recently, ethanol companies have been using different extraction techniques to remove various parts of the DGS to sell separately, such as corn oil and fiber. Previous research trials have tried to determine the contribution of individual nutrients in distillers grains that improve performance in order to predict the impact of removing certain components. In previous studies, fiber …

Assessing Plant-Wax Markers As A Tool To Estimate Intake And Diet Composition In Beef Cattle, Emily J. Hilburger

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

Estimating feed efficiency of ruminants in grazing environments is difficult due to challenges in measuring intake and diet composition of animals that are freely grazing. Plant-wax markers, especially n-alkanes (ALK), have been shown to be a potential tool to calculate intake and diet composition.

Two indoor experiments were conducted in successive years to assess ALK reliability to facilely estimate DMI (EDMI) and diet composition. Heifers were fed a ration of 69.8% corn silage and 30% ground alfalfa with a daily supplement containing a ALK marker (C₃₂). Using a pooled fecal sample increased the …

Evaluation Of Protein And Fiber From Distillers Grains Plus Solubles In Finishing Beef Cattle Diets, Zachary E. Carlson

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

Four studies were conducted to evaluate the components of distillers grains plus solubles in finishing beef cattle diets. Experiment 1 evaluated the effects of five composites of feedstuffs formulated to be similar in nutrient composition to DDGS on finishing performance of cattle. Experiment 2 evaluated isolating the protein from distillers grains using a feedstuff from the wet milling ethanol industry to determine the impacts of protein on the feeding value of WDGS in finishing performance of cattle. Experiments 3 and 4 evaluated the effects of protein from distillers grains with the diets used in Exp. 2 on site of digestion, …

Use Of Byproducts In Forage-Based, Post-Weaning Beef Systems And Effects Of Serial Slaughter On Performance And Profitability, Robert G. Bondurant Jr.

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

Crude glycerin was included in high-forage beef growing diets at 0, 4, 8, and 12% diet DM to determine the effect on fiber digestion by evaluating changes in microbial species abundance, NDF digestibility, and VFA concentrations. Total tract NDF digestibility decreased with increasing inclusion of GLY in high-forage diets. However, there was no decrease in in situ NDF digestibility and Fibrobacter succinogenes microbial populations were unaffected, indicating that fiber digestion was not directly affected by inclusion of GLY. Acetate decreased while propionate and butyrate VFA proportions increased as GLY increased.

Spayed heifers were utilized in a 2-yr study to evaluate …

Backgrounding Calf Management Strategies Using Corn Residue And Double Cropped Forages, Jordan L. Cox-O'Neill

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

Approximately 70% of calves in the U.S. are born in the spring and weaned in the fall, this results in a large supply of calves potentially available for backgrounding over the winter. Backgrounding systems positively impact the beef industry by efficiently using forage resources available. These systems also provide production value by enhancing the calf’s frame size, mature BW (increase HCW), and health prior to entering the feedlot. In Nebraska opportunities to integrate both crop and livestock production, by backgrounding calves abound. Approximately 13,100 metric tons of corn residue or 34,000 Animal Unit Months are available for grazing in Nebraska. …

The Role Of Stress Factors In Skeletal Muscle Development, Growth, And Metabolism; Impacts Of Temporally Spaced Repetition On Long-Term Information Retention In An Anatomy And Physiology Course, Caitlin Cadaret

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

We sought to identify the effect of sustained maternal inflammation at mid-gestation on fetal mortality, skeletal muscle growth, and development at term. Fetal rats had reduced total mass that coincided with impaired myoblast function, as myoD was reduced and myogenin expression was increased in hindlimb muscle. Fetuses also had increased circulating TNFα at term after maternal inflammation, which decreased TNFR and IL6R mRNA in muscle, reducing sensitivity to cytokines. These findings indicate that sustained maternal inflammation at mid-gestation impairs fetal skeletal muscle growth near-term due to changes in myoblast responsiveness to inflammatory regulation.

To evaluate the acute impact of inflammatory …

The Effects Of Xylanase Or An Algal Sourced Zinc Polysaccharide Complex On The Performance Of Laying Hens Fed A Corn And Soybean Diet, Ashley Bigge

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

Two studies were conducted to determine the effects of two different feed additives on the performance of laying hens. Study 1 examined the effects of non-starch polysaccharide degrading enzyme inclusion in a low energy diet. Study 2 examined the effects of supplementing a paramylon zinc polysaccharide complex at increasing concentrations. Both studies utilized a randomized complete block design for treatment assignment, and data were analyzed using the Glimmix procedure in SAS 9.4 for windows.

The first study took place July 2014 to March 2015 and consisted of two phases. Each phase tested a positive control, negative control with lower ME …

Effect Of Backgrounding Management Strategies On The Performance And Profitability Of Yearling Beef Cattle, Cody A. Welchons

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

Performance and profitability of steers grazing smooth bromegrass during the summer was evaluated. Steers grazed bromegrass with no supplement (CON), grazed bromegrass fertilized with 90 kg N/ha (FERT), or grazed bromegrass and were supplemented with distillers grains plus solubles (DGS) at 0.6% of BW (SUPP). Supplemented steers had increased ADG compared to CON and FERT steers. Profitability was greatest for the SUPP steers due to increased ending BW at the end of the grazing season. Steers grazing fertilized pastures were more profitable than CON steers due to increased stocking rate as a result of improved forage growth.

A 2-yr study …