Life Sciences Commons^™

Impact Of Wood-Sourced Biochar On Carbon And Nitrogen Capture In Beef Feedlot Systems, Jessica L. Sperber

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

A feedlot growing and finishing experiment evaluated the effect of including pine-sourced biochar at 0.8 (growing) and 1.0% (finishing) of dietary DM on steer performance, carcass characteristics, and greenhouse gas (GHG) production (Exp 1). Two nutrient mass balance experiments were conducted during winter and summer seasons to evaluate the effect of spreading unprocessed red cedar biochar on the feedlot pen surface on manure nutrient capture and cattle performance (Exp 2). In Exp. 1, the inclusion of biochar in the growing diet did not impact steer performance. The inclusion of biochar in the finishing diet significantly reduced intake and gain, resulting …

Management Of Late Summer Planted Annual Forages For Grazing And The Impacts Of Novel Sweet Bran Plus Products On Performance And Carcass Characteristics Of Beef Finishing Steers, Devin Jakub

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

Two separate grazing studies were conducted to evaluate: 1) the effects of rapeseed inclusion into late summer planted oats on the performance of growing steers during late fall and winter (Exp. 1) and 2) the effects of forage allocation on forage utilization and performance of steers grazing a late summer planted oat-rapeseed mix (Exp. 2). Variation in the corn wet milling process can result in negative effects on animal performance, nonetheless, there remains interest in further exploration and refinement of corn wet milling byproducts to achieve optimal byproduct compositions and cattle performance. Thus, another experiment was conducted to evaluate the …

Utilizing Online Resources To Enhance Distribution Of Competitive Animal Evaluation Knowledge And Benefits, Brooke L. Parrish

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

In recent years, the shift toward online education has revealed new challenges for learners to retain information, and for educators to find new and engaging ways to present content. This mixed methods, action research study explores the need and creation of online resources for competitive horse judging through surveys and pilot groups. The study was broken into four cycles. The first was an adult learner analysis survey, distributed through email Listservs and extension social media pages, to aid in answering the research questions: what expert horse judging instructors indicate their students should be learning, and what resources they need. Based …

Greenhouse Gas Emissions From Two Contrasting Beef Systems From Birth To Slaughter In Eastern Nebraska, Levi Mcphillips

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

Over the last 15 years, the increase in land use for corn and soybean has come at the expense of acres of grasslands and perennial forages employed in conventional beef-production systems. Implementing alternative cow-calf production systems into existing cropping systems may be a solution for reduced land availability and reducing total greenhouse gas emissions (GHG). Therefore, GHG from a conventional (CONV) pasture-based cattle production system with cows wintered on corn residue and summer grazing of brome pasture were compared to partial-confinement system (ALT) with cows and calves in a drylot during the summer and grazing cover crops and corn residue …

Feeding A New Corn Milling Coproduct To Lactating Dairy Cattle; Examination Of Whole Animal Energy And Nitrogen Balance, Addison Carroll

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

New coproducts are continually developed in the ethanol production industry. With that, the new product originates from the dry milling process which is unlike the traditional process as nitrogenous based particles are concentrated from the residual fiber by sieving post fermentation. Although high protein coproducts have been available since the mid 2000’s. These new products must be evaluated for chemical composition so that they can be accurately described in feed libraries that are used in commercial ration formulation software. While chemical composition provides us an initial and useful description of a feed product, in vivo nitrogen and energy balance studies …

Small Grain Cereal Cover Crops For Late Fall Or Early Spring Grazing, Kallie Calus

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

Beef cattle operations are confronted with early spring and late fall forage deficiencies. Producers in integrated crop and livestock systems can fill forage gaps using cover crops as a forage source in between cash crops.

A five-year study evaluating forage production, growing calf performance and economics of grazing an oats cover crop planted after corn silage (CS) and high moisture corn (HMC) corn harvests was conducted. The economic analysis accounted for costs of establishing and grazing the oats and the value of calf gain to determine fall grazing system profitability. Steers had greater average daily gain grazing oats after CS …

Host Genetics And Phenotype Associations Within The Bovine Rumen Microbiome, Waseem Abbas

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

Rumen microbes have a symbiotic relationship with the host where the host provides a suitable environment and microbial fermentation fulfill nearly 70% of the energy needs of the host. Rumen microbes play a central role in host performance and health. To date, most rumen microbiome studies have focused on the influence of diet on microbial species composition. In addition to dietary factors, studies have suggested that host genetic markers could influence the colonization of gastrointestinal microbiota. However, our understanding of the host-microbiome interaction and how host phenotype is influenced by the rumen microbiome is limited. This dissertation demonstrates: (1) host …

Evaluation Of Cattle Management For Systems With Limited Perennial Pasture, Morgan Grabau

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

Due to the conversion of perennial pasture and hay land to cropland in the western corn belt region, alternative methods of cow/calf management are being used to decrease reliance on perennial forages. These include grazing corn residue and feeding cow/calf pairs in confinement. Previous research has shown that limit-feeding a diet of low-quality forage and energy-dense co-products to cows in confinement is cost-effective. However, this strategy may limit the intake of the young calf and thus their performance. A study was conducted to evaluate the impacts of two alternative calf management strategies when pairs are in confinement, early weaning or …

The Effects Of Omega-3 Pufa Infusions During Late Gestation On Developmental Pathologies In The Intrauterine Growth Restricted Fetus, Taylor Lacey

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

Low birthweight due to intrauterine growth restriction is associated with metabolic disorders after birth. Our 1^st study assessed deficits in skeletal muscle glucose metabolism and pancreatic β cell function in IUGR fetal sheep. We aimed to evaluate the effectiveness of daily intravenous infusions of the anti-inflammatory ω-3 polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA), as a means of improving deficits previously observed in the IUGR fetus by targeting fetal systemic inflammation. The presence of systemic inflammation in IUGR fetuses was evident by increased total circulating populations of total leukocytes, lymphocytes, and monocytes. However, these were …

The Role Of Fatty Acids In Ruminant Diets And Novel Feed Ingredients High In Omega– 3 Fatty Acids Fed In Feedlot Diets, Mitchell M. Norman

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

A finishing study evaluated the performance, carcass characteristics and fatty acid profiles of steers fed four inclusions of a novel feedstuff Green Grass. Green Grass is a product comprised of sesame meal, giant kelp, cassava, and sorghum containing high concentrations of polyunsaturated fatty acids. No differences were observed in initial BW, final BW, BW gain, HCW, LM area, 12^th rib fat depth, calculated YG, or liver abscess %. Dry matter intake linearly increased as Green Grass inclusion increased in the diet. Steers fed Green Grass had lower G:F than control cattle, and steers fed 30% Green Grass had a …

Estimation Of Breed Effects And Genetic Parameters For Age At Slaughter And Days To Finish In A Multibreed Beef Cattle Population, Lindsay Upperman

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

Cattle efficiency during the finishing phase is a crucial factor in determining profit in the beef cattle industry. Economically relevant traits associated with efficient production include age at slaughter (AAS) and days to finish (DtF). Selection to reduce the number of days an animal takes to reach a finish endpoint would ultimately reduce production costs, increase net profits, and result in a more sustainable production system. However, most harvested animals are from commercial herds, necessitating the use of indicator traits from seedstock animals for selection. Potential indicator traits include ultrasound measurements that could be genetically correlated to DtF traits. The …

Low-Oxygen Dry Aging Of Beef, Joseph Sonderman

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

The objective of this research project was to determine the effects of removing oxygen from the beef dry aging process. Boneless upper 2/3 Choice beef strip loins (n=18) were randomly assigned to three aging treatments: wet aging, traditional (aerobic) dry aging, and low-oxygen dry aging. All treatments were aged for 41 days at 2 ± 1°C. The dry-aged treatments were held at 50% relative humidity (RH) with a fan speed of 2,200 revolutions per minute (RPM). Low-oxygen dry-aged samples were aged in chambers housed within an oxygen impermeable film bubble. After aging, yield was determined for the dry-aged samples. There …

Enhancement Of Dry-Aged Beef Quality By Dietary Supplementation Of High Levels Of Vitamin E, David Velazco

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

Crossbred cattle (n = 150; 10/pen) were grain-finished with the dietary addition of 2,200 international units of vitamin E (α-tocopherol) per head per day for 100 days. One low-Choice carcass (n = 12) was selected, and strip loins were collected. Low Choice control carcasses (n = 12) were randomly selected from commercial, fed-cattle production to serve as controls. Strip loins were randomly assigned to wet or dry aging for 42 days. On day 42, control dry-aged and control wet-aged loins had the highest TBARS values and vitamin E wet and dry-aged loins had lower TBARS values (P = 0.043). …

The Effect Of Heat Stress And Beta-Adrenergic Agonists On Fatty Acid Mobilization And Their Individual And Interacting Impact On The Adipose Transcriptome Of Ruminant Livestock, Rachel R. Reith

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

Heat stress reduces livestock efficiency, induces inflammation, and alters adipose tissue metabolism through stress-induced epinephrine acting on beta-adrenoreceptors (β-AR). Supplementation of beta-adrenergic agonists (β-AA) improve livestock growth and carcass traits, also by acting on β-AR located in skeletal muscle and adipose tissue. The binding of β-AR in adipose tissue results in changes in adipose tissue metabolism including increased lipolysis and decreased fatty acid synthesis. Due to their similar effects on stress response pathways, the possible interaction of heat stress and β-AA could negatively impact animal well-being. The purpose of the first study was to understand how ractopamine (RAC), a beta-one …

Quantification And Repeated Measurements Of Conformation Traits In Replacement Females To Optimize Sow Longevity, Melanie D. Trenhaile Grannemann

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

The objectives were to 1) assess the reliability of objective conformation trait measurements between evaluators, 2) evaluate effects of dietary energy and lysine during development and housing system during first gestation on longevity, reproductive performance, and conformation, 3) characterize conformation changes throughout life, 4) identify phenotypic associations between conformation and longevity, 5) estimate heritability of conformation traits, and 6) assess genetic relationships between conformation traits measured throughout life in sows. Sows (n = 622) were fed a standard, energy restricted, or standard energy with increased lysine diet during gilt development and housed in either a group pen or stall during …

Evaluation Of Grain Type And Processing Method On Steer Performance, Carcass Characteristics, And Nutrient Digestion, Caitlin Coulson

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

A feedlot finishing study evaluated the effect of replacing corn with dry-rolled wheat in diets containing wet distillers grains plus solubles (WDGS; Exp 1). Two studies were conducted to evaluate the effect of corn type [dry corn (DC), high-moisture corn (HMC), or a blend of dry and high-moisture corn (BLEND)] processed with either AutomaticRoller Mill (ROLL) or hammer mill (HAMMER) on steer performance, carcass traits, and nutrient digestibility (Exp. 2 and 3). In Exp. 1, steers were fed diets containing 100% dry-rolled corn (DRC) or a 50:50 blend of dry-rolled corn and wheat (WHEAT) in diets containing 12 …

Understanding Rumen Microbial Community Structure And Function Towards Decreasing Methane Emissions, Allison L. Knoell

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

Resource use is continually being limited due to this growth, therefore, production of high-quality animal protein sources, such as meat and milk, are challenged. The rumen microbiome is extensive and serves to provide several metabolic requirements for the animal for growth. Recently, a significant amount of research is being driven towards understanding the rumen microbiome due to its large effect on metabolic requirements.

A study was conducted to replace alfalfa with nonforage fiber sources in dairy cows. It was determined milk yield and intake are maintained when nonforage fibers replace forage sources, while decreasing methane levels. Water consumption decreased when …

The Effects Of Different Feed Supplements On Performance Parameters, Egg Measurements, And Eggshell Integrity In Older White Leghorn Laying Hens, Josephine Foley

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

Two studies were conducted to evaluate the efficacy of multiple feed additives on the performance of older White Leghorn hens. Study 1 examined the effects of 2 vitamin/mineral supplements and 1 medium chain fatty acid. Study 2 examined the effects of a novel butyric acid product, a tributyrin ester. Both studies followed a completely randomized design with repeated measures and data were analyzed using the Glimmix procedure in SAS version 9.4 for Windows.

The first study took place November 2015 to April 2016. Trt 1 was a control diet, Trt 2 was supplemented with a Ca, Fe, Mn, Cu, Zn …

Changes In Whole Blood Parameters In Beef Heifers May Contribute To Delayed Pubertal Attainment, Jessica A. Keane

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

Pubertal development in beef heifers is a transient period that has many contributing factors. Previously in our lab, progesterone (P4) concentrations collected from heifers at weaning (Oct) to breeding (May) were used to identify four distinct pubertal groups: Typical, Early, Start-Stop, and Non-Cycling. There is limited research on heifers and the impacts of whole blood cell populations, particularly WBCs, during pubertal development; however, girls with differing puberty onset displayed altered concentrations of hematocrit, white blood cells (WBC), and hemoglobin concentrations. Thus, our hypothesis was that heifer pubertal groups with delayed or precocious puberty may have increased white blood cells or …

Evaluation Of Condensed Algal Residue Solubles As An Ingredient In Cattle Finishing Diets And Its Effects On Digestibility And Fatty Acid Flow And A Comparison Of Single And Dual Implant Strategies In Finishing Heifers, John Gibbons

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

Two experiments, a performance study (Exp. 1) and digestion study (Exp. 2) were conducted to evaluate a novel liquid feed, condensed algal residue solubles (CARS), in feedlot diets. In Exp. 1 and Exp. 2, steers were fed three inclusions of CARS at 0%, 2.5%, 5%. There were quadratic responses for greater carcass adjusted final BW, ADG, G:F, HCW, 12^th rib fat, and yield grade. There was a linear increase in marbling score and a linear decrease in DMI and LM area as CARS increased. In Exp. 2, CARS did not affect intake or digestibility. Fatty acid flow at the …

Variation In The Genome And Transcriptome Associated With Beef Cattle Production And Investigation Of The Metabolic Consequences Of Beta-Adrenergic Agonist Supplementation, Renae L. Sieck

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

Beta-adrenergic agonists (β-AA) are widely used supplements in livestock production to improve feed efficiency and increase lean muscle mass. Heat stress is one of the largest economic burdens to the livestock industry due to production efficiency losses and morbidity and mortality of animals. Both β-AA and catecholamines released in response to heat stress bind to β-adrenoceptors on the skeletal muscle cell surface to activate downstream signaling pathways. The purpose of this study was to determine if β-AA supplementation and heat stress have an additive effect on the skeletal muscle transcriptome. 3’ RNA sequencing of samples of the longissimus dorsiwas …