Agriculture Commons^™

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …

Molecular Mechanisms Underlying Aberrant Circulating Steroid Hormones In Gnrhr-Ii Knockdown Boars And Their Control Littermates, Dorothy H. Elsken

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

Swine are the only livestock species that produce a functional protein for both GnRH-II and its receptor (GnRHR-II). Our laboratory reported that the interaction between GnRH-II and GnRHR-II facilitates testosterone production, independent of LH stimulation. To further examine GnRHR-II function, we developed a swine line with 70% reduced GnRHR-II mRNA levels (GnRHR-II KD) compared to control littermates. Mass spectrometry analysis of serum revealed that circulating levels of gonadal steroids were reduced in mature transgenic vs. control boars. Paradoxically, evaluation of testicular tissue indicated no difference between lines for gonadal steroid hormone levels. To address a potential cause for this discrepancy, …

The Invisible Meat Microcosmos: Investigations Of Processed Meats' Specific Spoilage Organisms, Rebecca Furbeck

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

As humankind grows in population, so will our need to compete against bacterial populations which spoil foodstuffs before we are able to consume them. This dissertation aims to identify the bacterial communities responsible for meat spoilage, and the mechanisms that govern the behaviors of these organisms. The literature review summarizes the state of knowledge regarding factors that influence meat microbiome composition, and how analytical methods can influence research outcomes. Study 1 aimed to identify the impact of additional ingredients and processing steps on the microbial ecology of processed turkey products. The main specific spoilage organisms (SSOs) belonged to the orders …

Impacts Of Feeding Biochar To Beef Cattle On Greenhouse Gas Emissions And Performance And Characterizing Yearling Steers Grazing Smooth Bromegrass Pasture Using Gps, Holly A. Heil

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

As global warming continues to rise, the pressure and growing demand for sustainable animal production is increasing. Livestock naturally produce greenhouse gas emissions through enteric fermentation. Dietary manipulation strategies have been sought out to decrease emissions in ruminants using feed additives.

Two independent finishing feedlot experiments evaluated two types of biochar and its effects on animal performance, carcass characteristics and greenhouse gas emissions. Experiment 1 utilized pistachio shell biochar and experiment 2 utilized biochar sourced from ponderosa pine wood waste, both types included at 1% of the diet DM. The addition of biochar to the diet did not impact animal …

The Nebraska 4-H Equine Advancement Level Program’S Role In Positive Youth Development Using The Five Cs Model: An Exploratory Study, Eunhye Mccarthy

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

Positive youth development (PYD) focuses on developing the strengths of youth through positive activities and behaviors rather than reducing negative tendencies. A well-researched model of PYD is the five C’s model that is popularly used in youth development organizations such as 4-H. The Nebraska 4-H Equine Advancement Level program was intended to serve as a guidebook for instruction and assessment of youth as they learn more about horses and horsemanship skills. Each of the four levels has an emphasis in developing a 4-H member’s responsibility, self-discipline, self-reliance, patience, and pride of accomplishments. The program was started approximately 30 years ago …

Variance Component Estimates For Growth Traits In Beef Cattle Using Selected Variants From Imputed Low-Pass Sequence Data, Chad A. Russell

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

A beef cattle population (n = 2,343) was used to assess the impact of variants identified from imputed low-pass sequence (LPS) on the estimation of variance components and genetic parameters of birth weight (BWT) and post weaning gain (PWG). Variants were selected based on functional impact and were partitioned into four groups (Low, Modifier, Moderate, High) based on predicted functional consequences and re-partitioned based on consequence of mutation, such as missense and untranslated region variants, into six groups (G1-G6). Each subset was used to construct a genomic relationship matrix (GRM) for univariate animal models. Multiple analyses were conducted to …

Evaluation Of Nutritional Factors Affecting Sow Reproductive Longevity, J'Nan E. Wittler

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

Sow reproductive longevity is an important trait for swine operations from a production and economic standpoint. Previous research has shown that a sow needs to produce 3 litters before she covers the costs associated with introducing her to the operation. A literature review of research conducted related to sow longevity is discussed in Chapter 1. Chapters 2 and 3 present data from the University of Nebraska – Lincoln’s long-term sow longevity research. The research looks at the effects of energy restriction with soy hulls during gilt development on sow reproductive longevity through 4 parities. Chapter 2 presents data from replications …

Students' Perceptions Of Online Equine Courses And Their Impacts On Learning Outcomes, Blaire L. (Gibbens) Speck

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

Post-secondary education is always changing and evolving. Over the last few years, significant changes in education have resulted in an increased number of online courses. Approximately 28% of students seeking higher education participate in at least one online course and 14% are enrolled exclusively in distance or online programs (Allen & Seaman, 2016). However, courses that are typically hands-on, like equine science, may be more challenging online. The hands-on experiences in equine science classes help prepare students for future careers. Due to an increase in students choosing to take courses online, a review of online teaching methods was conducted to …

Arkansas Soybean Research Studies 2021, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading soybean-producing state in the mid-southern United States. Arkansas ranked 11th in soybean production in 2021 compared to the other soybean-producing states in the U.S. The state represented 3.49% of the total U.S. soybean production and 3.49% of the total acres planted in soybean in 2021. The 2021 state soybean average yield was 52.0 bushels per acre, setting a new state record and surpassing the previous yield record of 51.5 bushels per acre set in 2020. The top five soybean-producing counties in 2021 were Mississippi, Phillips, Crittenden, Poinsett, and Arkansas (Table 1). These five counties accounted for …

Seroprevalence And Titer Concentration Testing For Leptospirosis In Equine, Ashley Himmelsbaugh

Honors College Theses

The most common best management practice used to combat diseases in horses is vaccination, which can decrease the incidence or severity of illness. However, the duration of immunity will vary for each vaccination and must be considered for revaccination purposes. Titer concentration, which evaluates antibodies in the blood, may be a helpful way of determining how long an animal has immunity to a disease. Leptospirosis, a zoonotic, bacterial disease, can result in uveitis, potentially leading to blindness, and abortion in mares. One serovar, Leptospirosis pomona (L. pomona), is associated with most cases of clinical disease in horses in North America. …

Successful Creation Of Seedless (Sterile) Leucaena Germplasm Developed From Interspecific Hybridisation For Use As Forage, Daniel Real, Clinton K. Revell Dr, Yong Han, Chengdao Li, Marieclaire Castello, C. D. Bailey

Grain and Other Field Crops Research Articles

Context: The legume shrub/tree leucaena (Leucaena leucocephala (Lam.) de Wit.) is highly regarded as a cattle fodder, although it is considered an environmental weed in many parts of Australia.

Aims: We investigated the feasibility of developing a forage variety of triploid leucaena through interspecific hybridisation that is sterile (without seeds) as a strategy to mitigate its weed risk.

Methods: A conventional breeding strategy was used to create triploid hybrids from hand-crosses between tetraploid and diploid species of leucaena. Molecular markers were developed to confirm successful crosses and flow cytometry was used to confirm the ploidy level. The plants are being …

Environmental Determination Of Gastrointestinal Parasitism In Katahdin Sheep, Brian Arisman

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

Gastrointestinal nematodes (GIN) negatively affect the performance and wellbeing of sheep and are difficult to control due to anthelmintic resistance. Producers are therefore choosing breeds naturally resistant to GIN infection, such as the Katahdin. Katahdin are raised in various climates and management systems in the U.S., and those environmental factors can be combined into eco-management clusters. We hypothesized that GIN challenge varies predictably based on the characteristics of these clusters. Katahdin producers from across the U.S. were surveyed for management information. Body weights (BW), fecal egg counts (FEC) and FAMACHA scores (FAM) were collected on 3,527 Katahdin lambs around 90 …

Nitrification Inhibitor, Nitrogen Source, And Herbicide Effects On Soil Nitrogen Transformations And Corn Yield, William Neels

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen fertilizer management continue to be challenging due to potential nitrogen losses under variable weather conditions. The objective of this was to evaluate the performance of nitrification inhibitors, nitrogen sources and herbicides on in-season nitrogen availability and agronomy indicators. A two site-year field experiment was conducted in silty clay loam soil in corn phase of the corn-soybean rotation at Central Nebraska. The treatments included three herbicide (no pre-emergence, Acuron, Resicore) and five nitrogen treatments: 1) control, 2) anhydrous ammonia, 3) anhydrous ammonia without nitrification inhibitor, 4) urea with nitrification inhibitors, and 5) urea without nitrification inhibitors. Results indicated that nitrogen …

Deciphering The Genetic Architecture Of Key Female Floral Traits For Hybrid Wheat Seed Production, Juan David Jimenez

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wheat (Triticum aestivum L.) is a staple cereal that provides 20% of the calories and proteins in human intake (Ray et al., 2013). Global population is projected to increase to 9.7 billion by 2050. Food production must increase by 70% to feed this future population. Wheat production is in crisis due to political and environmental challenges and is projected to decline by 0.8% in 2022 (FAO, 2022). To ensure food security yield genetic gain must increase by around 1.4% annually. Taking advantage of heterosis, hybrid wheat has the potential to boost grain yield. However, hybrid wheat seed production systems …

Quantifying The Relationship Between Soil Organic Carbon And Soil Color In Nebraska, Aldi J. Airori

Applied Science Program: Theses

Soil color is easily measured in the field and holds potential to be used as an indirect measurement of soil organic carbon (SOC). The main limitation to this approach is knowledge about the specific color-SOC relationship in a region, which often varies in relation to parent material, soil texture, climate, and land use. Furthermore, the Munsell color data is subjective in nature. The objectives of this study are: 1) to develop and evaluate the accuracy of pedotransfer functions (PTFs) for the prediction of SOC based on soil color and texture in the state of Nebraska and 2) to evaluate digital …

A Glass Bead Semi-Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares, Daniel P. Schachtman, Sophie Alvarez, Karin V. Van Dijk

Department of Agronomy and Horticulture: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, …

Evaluation Of Extended Aging Type And Cooking Practices On Palatability Of Beef Steaks, Katharine Anne Bugenhagen

Graduate Theses and Dissertations

Two studies were conducted to determine if sous vide was a viable way to improve palatability of various beef cuts, and to determine whether extended aging duration and the presence of a bone impacts the consumer ratings of beef short loins.When evaluating the impact of sous vide cooking (SVG) on multiple beef muscles, there was a muscle × method interaction for overall liking (P = 0.04). The traditionally cooked (TRAD) Longisimus lumborum (LL) was rated the highest (P < 0.05). The Chuckeye steak (CHE) was rated next, both TRAD and SVG, with the traditional ranked higher, this was followed by the Triceps brachii (TB) also for both TRAD and SVG, however for the TB the SVG ranked higher (P < 0.05). The TRAD Biceps femoris (BF) rated the lowest (P < 0.05) of all of the muscles. Shear force did no differ between the cooking treatments (P > 0.05), or was there an interaction between muscle × method for shear force measurements (P < 0.05). The LL was rated the highest for tenderness (P < 0.05) while the BF was rated the lowest (P < 0.05). The second study compared subprimals aged over three aging periods (21, 42 63 days), then split into bone-in or boneless steaks, there were no interactions observed within the consumer data (P ≥ 0.05). BI steaks were rated higher (P < 0.05) for juiciness and overall liking by consumers, however BI and BL were rated similarly by consumers for tenderness and flavor (P > 0.05). When evaluated by consumers, aging did …

Investigating Quality Attributes And Wine Production Methods Of Arkansas-Grown Grapes, Amanda Fleming

Graduate Theses and Dissertations

Grapevines (Vitis species) are grown worldwide to produce table grapes, juice grapes, dried grapes, and wine with the United States as one of the world’s largest wine and grape producers. Though not a large contributor to the U.S. grape and wine industry, Arkansas’ industry plays an important role in the state’s agritourism and economy. Most grapes grown in Arkansas’ warm climate include native species, such as muscadines (V. rotundifolia) and hybrids (crosses of Vitis species). Two important hybrid red wine grapes grown in Arkansas are Chambourcin, grown commercially for its positive viticulture and enological quality, and Enchantment, a newer cultivar …

Timing Of Implants Use In Backgrounding System, Kylie M. Butterfield

Applied Science Program: Theses

A study was conducted over two years to determine the interactions of winter rate of gain at a high gain (HG) of 0.91 kg and low gain (LG) 0.45 kg, and implant strategy in the backgrounding and subsequent effects in the finishing phases. There were three phases in this study, the winter phase (~148 days), the summer phase (~60 days) and the finishing phase (~120 days). This was a 2 x 3 factorial design. The first factor is a rate of gain at either 0.91 kg (HG) or 0.45 kg (LG). The next factor is the timing of implant where …

Seeking Of Agriculture Information Through Mobile Phones By Rice Farmers In Ogoja Agricultural Zone, Cross River State, Nigeria, Friday O. Idiku, Ginini Francis Elemi, Ejeje Igwe Agube, Comfort Aya, Anthonia Egem Okem

Library Philosophy and Practice (e-journal)

Seeking agriculture information is common among rice farmers in many parts of the world. The study was aimed at assessing the Seeking of Agriculture Information through Mobile Phone by Rice Farmers in Ogoja Agricultural Zone of Cross River State Nigeria The specific objectives of the study were to; identify the socio-economic characteristics of the farmers, determine factors influencing the seeking of agriculture information through mobile phones by rice farmers, and to examine the constraints to use of mobile phones by rice farmers in Ogoja Agricultural Zone of Cross River State Nigeria. A multistage sampling technique was adopted to select ninety …