Animal Sciences Commons^™

Effects Of Hot Water Dipping And Sub-Zero Saline Chilling On The Microbial Safety Of Broiler Carcasses And Recycled Chilling Water, Elen Zhu

Master's Theses

Broiler meat became the most widely consumed meat within the United States and across the world in 2019. The trend of increasing broiler consumption is expected to continue due to affordability, health benefits, and production efficiency. To meet the growing demand of broilers, a substantial number of birds need to be produced and processed while minimizing bacteria contamination, water consumption and wastewater generation.

In this study, the microbial safety (mesophilic aerobic bacteria, coliforms, and Escherichia coli) of broiler carcasses and post-chill water (red water) was assessed, using innovative processing techniques and red water recycling. A total of 144 broilers …

Independent And Combined Effects Of Early-Life Iron Deficiency And Antibiotic Exposure On Growth And Hematological Outcomes In A Piglet Model, Ginger M. Fitzpatrick

Master's Theses

Iron deficiency (ID) affects over 2 billion individuals globally. Children under 5 are at increased risk of ID due to rapid growth and are especially vulnerable to its negative consequences because of iron’s essential role in cognitive development and immune maturation. ID is the leading cause of iron deficiency anemia (IDA), with IDA affecting approximately 40% of children in this age group. Antibiotic (abx) exposure is also prevalent during early life and may disrupt growth and through gut dysbiosis, with increasing use posing additional risk in younger populations. Geographically, there is overlap in regions with high anemia prevalence and those …

Serum Concentrations Of Inflammatory Markers And Selected Nutrient Metabolites In Holstein And Jersey Cows Across The Transition Period, Avery Orr

Master's Theses

The transition period, spanning the weeks surrounding parturition, requires dairy cows to undergo synchronized metabolic, endocrine, and immunological adjustments that support the onset of lactation but also heighten disease susceptibility. Although individual inflammatory or metabolic biomarkers have been extensively studied, the integrated immunometabolic dynamics that occur across this period and the difference between breeds is not fully understood. The objective of this study was to characterize longitudinal patterns in key nutrient metabolites and inflammatory markers in Holstein and Jersey cows and assess how these systems interact across the transition period.

A total of 63 Holstein and Jersey cows were sampled …

Associations Between Feed Efficiency And Feeding Behavior In Yearling Angus Bulls In A Competitive Environment, Amelia Katz

Master's Theses

Feed efficiency in beef cattle is a complex trait shaped by physiological, behavioral, and social factors that influence how animals access and utilize feed resources. This study examined feed efficiency classification and how it is influenced by feeding behavior, competitive interactions, and bunk approach patterns in yearling Angus bulls housed in a drylot over two years. Bulls were grouped into high and low feed efficiency categories using residual feed intake and feed conversion ratio within pen and year (n = 40 per year; n = 40 per treatment). Continuous electronic monitoring quantified feeder visitation, feeding duration, intake, and rate. A …

Coyote (Canis Latrans) And Non-Target Wildlife Responses To Livestock Guardian Dogs At Sheep Grazing Sites On The California Central Coast, Tricia T. Nguyen

Master's Theses

Livestock depredation is one of the oldest and most widespread forms of human-wildlife conflict. The coyote (Canis latrans), a midsized canid, represents a significant proportion of domestic sheep depredations in the United States, costing livestock producers an estimated 24.6 million dollars annually. Management strategies for coyote-sheep depredation vary widely in their effectiveness and in their level of public support. Identifying appropriate strategies for farms, ranches, and other sheep grazing sites remains a pressing need due to the potentially negative consequences for surrounding ecosystems and socioeconomic outcomes for sheep producers. The livestock guardian dog (LGD) is a nonlethal control …

Effects Of Spirulina And Nannochloropsis Supplementations On The Meat Quality And Sensory Properties Of Broiler Carcasses, Shreyash S. Patel

Master's Theses

Microalgae are a promising feed ingredient due to their high content of proteins, lipids, polysaccharides, vitamins, pigments, and enzymes. This study evaluated the effects of algae as a dietary supplementation on the appearance, quality, and sensory attributes of broiler carcasses. In each of experiment I and II, a total of 54 Ross-708 broilers were randomly obtained from the pool of 270 broilers in the 18 floor pens of soybean-mealbased diets at 0, 2.5%, and 5% Spirulina (Experiment I) and Nannochloropsis (Experiment II) supplements in the Poultry Unit at California Polytechnic State University (Cal Poly, San Luis Obispo, CA). Broiler carcasses …

The Effects Of Sirulina And Nannochloropsis Supplementation On Broiler Performance, Intestinal Morphology, And Gut Microbiology, Emily Beckerman

Master's Theses

The poultry industry is constantly searching for new nutritional strategies and better feed conversion ratio to enhance broiler growth and productivity. Microalgae have been shown to improve broiler performance and health depending on species and supplementation levels. The objective of this study was to determine the effects of Spirulina supplementation (Experiment I) and Nannochloropsis supplementation (Experiment II) on broiler production performance, intestinal morphology, and gut microbiology. In Experiment I, a total of 270 broiler chicks (one-day-old Ross 708) were obtained from a local hatchery after vaccinating against Newcastle, Marek’s disease, and Infectious Bronchitis. They were weighed and sorted into 18 …

Seal Counting On Our Plages (S.C.O.O.P.), Kaanan Kharwa

Master's Theses

The Vertebrate Integrative Physiology (VIP) lab monitors the population of northern elephant seals at the largest mainland breeding colony, located at Piedras Blancas (San Simeon, CA). As the population expands, more human-seal interactions and conflicts over land use occur. The VIP lab's work informs California State Parks and helps with the management of the rookery. Currently, members of the VIP lab fly a drone over the beaches, capture multiple images, and manually count the seals, which takes around 14 to 21 hours of analysis per survey. Machine learning methods such as Convolutional Neural Networks (CNN) and Region-based Convolutional Neural Networks …

The Effect Of Probiotic Supplementation On Serum Metabolite Concentrations In Young Holstein Heifers, Emily G. Meissner

Master's Theses

The objective of this trial was to evaluate the effect of a multi-strain probiotic on serum concentrations of selected metabolites in young calves. Holstein heifers (n = 112) from a commercial dairy were enrolled within 48 h of birth and placed into individual hutches. Calves were weaned at 60 d of age and remained in their hutches until 90 d of age, when they were moved to group housing. Calves were placed into 2 treatment groups: 1) control and 2) B. subtilis, B. lichenformis, L. animalis, and P. freudenreichii probiotic (Bovamine Dairy Plus, Chr. Hansen, Milwaukee, WI). Control calves received …

Aged 539 - Graduate Internship, Braidyn R. Cossa

Agricultural Education: Graduate Internship Reports

This report reflects on the Cal Poly Rodeo Program's alignment with the National Standards for Sport Coaches, showcasing a comprehensive approach to athlete development across multiple critical domains. Emphasizing a well-defined coaching philosophy, the program promotes sportsmanship, ethical behavior, and academic success. Personalized coaching addresses the developmental stages of athletes, ensuring a balance between their academic and athletic roles. The program employs effective teaching methods, clear communication, and constructive feedback to foster a positive environment and build strong coach-athlete relationships based on mutual respect and trust.

The coaches possess deep knowledge of rodeo skills and strategies, utilizing psychological techniques to …

Deep Ocean Vehicle Applications And Modifications, Nichole "Nikki" T. Arm

Master's Theses

This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.

I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I …

Effects Of Mature Recombinant Gdf9 And Bmp15 On In-Vitro Maturation Of Bovine Oocytes And Subsequent Embryo Development And Effects Of Antioxidants On Blastocyst Re-Expansion Rates, Jamie Thompson

Master's Theses

In-vitro produced embryos (IVP) differ greatly from in-vivo derived embryos (IVD) in gene expression, metabolism, development, and cryotolerance which limit the widespread use of this technology. In-vitro maturation (IVM) is one of the most important components for successful in-vitro embryo development. Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) have been found to be essential during oocyte maturation and thus female fertility. These proteins are oocyte secreted factors (OSFs) and are produced with pro- and mature protein regions where the pro-regions are thought to aid in protein folding and dimerization where heterodimerization the two proteins has been …

Integrative Analyses Of Genomic And Metabolomic Data Reveal Molecular Mechanisms Associated With Uterine Disease Traits In Transitioning Dairy Cattle, Leanna C. Sanchez, Mohammed Abo-Ismail, Daniel Peterson, Fernando Campos-Chillon

Master's Theses

The metritis complex (MC), characterizing post-partum uterine diseases in dairy cattle has negative implications on animal welfare, production efficiency, and the economic stability of the dairy industry. The studies in this thesis aimed to investigate the genetic architecture of the metritis complex and identify genomic regions and metabolites associated with the development of MC. Thereby enhancing our understanding of the biological pathways and molecular mechanisms involved in the pathophysiology of MC during the transition period in Jersey and Holstein dairy cattle.

Chapter 2 sheds light on the previous work done on MC. The goals of this review were to (1) …

Slo City Riparian Grazing Project Handbook, Jasmine Bramble, Marina Gutierrez

Animal Science

A handbook for future leads on this project. This project is about the vegetation surveying of several segments of Prefumo and San Luis creeks that flow through the city of San Luis Obispo. The city needs to open up the undergrowth in the creeks to allow crews to find and clear out debris for flood and fire prevention. We are mapping the vegetation to help Beth Reynolds plan where to set up temporary grazing units for her goats, and we will be photographing the condition of the creek (riparian) channels before the grazing begins and after in order to document …

Building Artificial Reefs From Recycled Construction Materials: A Feasibility Study, Nicholas H. Lew

Construction Management

Naturally occurring reefs are some of the world’s most biologically diverse ecosystems formed by jagged rocks tucked slightly below sea level. In recent years global warming began to pose a major threat to many reef habitats. Most relevant is the increase in surface seawater temperatures that cause coral to bleach, taking away major food sources for larger marine species. Researchers have combated this by deploying artificial reefs in substitution for naturally formed limestone rock formations in order to promote the expansion of coastal habitats. This project specifically aims to utilize construction waste towards the production of artificial reefs, effectively upcycling …

Beef Bull Selection And Management Affecting Breeding Season Outcomes For California Cattle Producers On Rangelands, Megan Banwarth

Master's Theses

California’s approximately 660,000 head of beef cattle are highly dependent on range bulls used to produce offspring that can perform across the state’s diverse ecological regions. While knowledge of bull breeding behavior and the technology used to monitor cattle movement and behavior is critical to maximize conception rates and the overall efficiency in natural service sires on rangelands. Bulls need to be functional on rugged coastal landscapes, rolling foothills, deserts, and in high-elevation terrain. Few data exist that indicate factors related to selection, maintenance, and longevity of bulls used in rangeland landscapes. Objectives herein, were to assess factors influencing bull …

A Comparative Study Of The Effects Of Microalgae On Poultry Production, Taylor Kaitlyn O'Lear Reid

Master's Theses

Research has shown Spirulina to be a viable feedstuff in poultry production. Other species of microalgae are being studied to determine their effects on poultry production. This project compared four microalgaes: Hydrodictyon, Vaucheria, Uronema, and Spirulina and was broken down into three trials. The first experiment investigated the digestibility of an algae species, Spirulina, in broiler chicken diets. Eighty, 25-day-old Ross 708 broiler chicks were sorted into 20 metabolism cages and received one of two diets: Control Diet or Test Diet (75% basal diet + 25% Spirulina). The apparent ileal amino acid digestibility (AIAAD) of lysine, methionine, cysteine, threonine, isoleucine, …

Cattle Producer Motivations And Willingness To Participate In Industry Animal Welfare Program Verification, Chase Decoite

Master's Theses

As consumers have become increasingly interested in where their food comes from and how it is grown, the cattle and beef industry is without exception. Many consumers are beginning to question traditional animal husbandry practices and on-farm animal welfare protocol. It is essential that the food system meets new demands and understands consumer views. In order to address these concerns, the industry has rallied around the Beef Quality Assurance (BQA) program to set the standard for cattle welfare and beef quality, with the explicit goal of improving consumer confidence. The goal of this research is to determine if cattle producers …

Sensory Stressors Impact Species Responses Across Local And Continental Scales, Ashley A. Wilson

Master's Theses

Pervasive growth in industrialization and advances in technology now exposes much of the world to anthropogenic night light and noise (ANLN), which pose a global environmental challenge in terrestrial environments. An estimated one-tenth of the planet’s land area experiences artificial light at night — and that rises to 23% if skyglow is included. Moreover, anthropogenic noise is associated with urban development and transportation networks, as the ecological impact of roads alone is estimated to affect one-fifth of the total land cover of the United States and is increasing in space and intensity. Existing research involving impacts of light or noise …

Lipid Quantification And Cryopreservation Of In Vitro Produced Jersey Cattle Embryos, Katherine A. Rhodes-Long

Master's Theses

Cryopreservation of in vivo derived Jersey bovine embryos have resulted in a 10% lower pregnancy rate compared to other dairy breeds. Poor embryo survival after cryopreservation has been partially attributed to the high lipid content of Jersey embryos. In vitro-produced (IVP) bovine embryos have darker cytoplasm than their in vivo-derived counterparts because of higher lipid accumulation. High lipid accumulation is associated with impaired embryo quality. Forskolin is an adenylate cyclase activator that regulates cAMP levels in cells and has been shown to induce lipolysis in IVP embryos. L-carnitine is required for transport of fatty acids from the intermembrane space of …

Artificial Night Lighting And Anthropogenic Noise Alter Animal Activity, Body Condition, Species Richness, And Community Structure, Joshua Willems

Master's Theses

Sensory pollution from artificial night-lighting and anthropogenic noise have increased at a dramatic rate over the last several decades. Alterations to the sensory environment have been found to affect wildlife in a wide variety of ways including behavioral changes, physiological responses, changes in species interactions, and altered community structure. Increased levels of light and noise pollution can originate from many sources including roads, energy development and infrastructure, and urbanization. Even remote or protected areas are not immune to the effects of increased sensory disturbances with 63 percent of protected areas within the United States found to have been exposed to …

Saturday Night Live Club Lamb Sale, Tyler P. Wilkerson

Agricultural Education and Communication

“Competition is said to be the backbone of the stock show industry,” (Davis, 1998). A statement spoken in a 1998 thesis paper on the junior livestock industry still holds water in today’s world. Youth livestock exhibition, especially in California, continues to grow in the number of youth participants and the number of livestock entries at shows (Switzer, 2019).

It is the responsibility of livestock breeders to breed, raise, and sell their livestock to maximize the opportunity for youth to acquire livestock to show. In his research, Wendt discusses the capabilities of purchasing livestock through online platforms. He speaks to the …

Maturation And Culture Media Effects On In Vitro Bovine Embryo Developmental Competence, Ciara M. Helland

Master's Theses

In vitro produced bovine embryos are critical to the cattle industry. However, these embryos have altered morphology, epigenetics, and metabolism when compared to their in vivo counterparts. The aim of this thesis was to alter maturation and culture media to improve the developmental competence of in vitro bovine embryos. This thesis is comprised of three experiments and one proof of concept study. Each experiment followed the same general layout: oocyte aspiration from Jersey or Holstein ovaries, oocyte maturation for 24 hours, fertilization with bull semen for 24 hours, then embryo culture for 7-8 days in 38.5 °C in 5% O …

Reduction Of Fat Content In Processed Meats Using Hot-Boning And Cold-Batter Mincing Technology, Morgan P. Wonderly

Master's Theses

Processed meats have received negative publicity due to high fat contents that have been linked to adverse effects on human health. Fat is an essential ingredient in many processed meat products, so reducing this all while maintaining the desired characteristics of the product is a challenge. The purpose of this study was to generate low-fat meat products using a combination of hot-boning/crust-freeze-air-chilling (HB-CFAC) and cold-batter mincing (CBM) technologies. Pork hams were subjected to HB-CFAC or chill-boning/crust-freeze-air-chilling (CB-CFAC) prior to 3 min pre-mincing and 6 min mincing for control gels with back-fat addition or low-fat gels with water addition instead of …

Valorization Of Carrot Processing Waste, Alexandra M. Duval

Master's Theses

Commercial carrot processors produce up to 175,000 tons of carrot waste annually. Carrot Mash (CM) is the term referring to the waste by-product of peeled baby carrot processing. Transportation of carrot processing waste is expensive due to its high- water content (approx. 83-95%). High in bioactive compounds (carotenoids) and dietary fibers, it is expected that its conversion into a value-added by-product is of interest to the carrot processing industry. Hemicellulose-rich plant materials have proven to be a source of oligosaccharides, which are known for their beneficial prebiotic activity. The objectives of this research were to: 1) determine the effect of …

Evaluation Of Chilling Efficiency, Meat Tenderness, And Microbial Analysis Of Broiler Carcasses Using Sub-Zero Saline Solutions, Samira Viliani

Master's Theses

The poultry industry is seeking an advanced chilling system that can improve chilling efficiency, microbial safety, and water consumption without compromising meat quality. The objective of this study was to evaluate the effects of sub-zero saline chilling methods on chilling efficiency, breast fillet tenderness and microbial reduction of broiler carcasses. Following evisceration and rinsing, broiler carcasses were randomly assigned to one of three chilling solutions: 1) 0% salt or ice water control (0% NaCl/0.5^oC), 2) 3% salt (3% NaCl/-1.8^oC), and 3) 4% salt (4% NaCl/-2.41^oC) solutions. Broiler carcasses in sub-zero saline solutions reached the …

Creating Online Training Modules For Student Employees At The California Polytechnic State University Dairy Using Train Trac, Olivia K. Taylor

Agricultural Education and Communication

The purpose of this project was to create training modules for the Cal Poly Dairy. The author’s goal was to incorporate the safety aspect of dairy work into the modules as well. To properly obtain all the necessary information for the modules, the author first had to compile lists from the Cal Poly Dairy’s written standard operating procedures. From here, the majority of time was used to gather video and picture content using a surface tablet that would later be used in the online modules. Once the content was gathered, it had to be organized into files for each module …

The Horse's Back As Influenced By Saddle Fit, Katie Millican

Agricultural Education and Communication

Therefore, this project will use devices called the Lameness Locator and a thermal camera along with facilities at the Equine Center in San Luis Obispo, California. The objective of the project is to utilize a population of sound horses and compare the heat detection images of their backs and saddles after being ridden to provide saddle fit data. This project will provide information contributing to closing the gap of equestrians uneducated about the importance of saddle fit.

The reason for researching and conducting a study to prove this point is simple: a horse owner needs to look at the bigger …

Development Of A Pediatric Model Of Nafld In Neonatal Iberian Pigs, Gabriella Veronica Hernandez, Victoria Alice Smith, Morgan Coffin, Daniel Columbus, Matthew Burd, Kimberly Sprayberry, Mark Edwards, Daniel Peterson, Darin Bennett, Robert Fanter, Christopher Kitts, Michael La Frano, Margaret Rice, Douglas Burrin, Magdalena Maj, Rodrigo Manjarin

Master's Theses

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children has increased over the past decades, creating a need for animal models that recapitulate the features of the pediatric disease. Iberian pigs have a leptin-resistant phenotype characterized by hyperleptinemia, hyperphagia, and extreme adipogenesis. We hypothesized that neonatal Iberian pigs fed a high fat high-fructose (HFF) diet will develop a pattern of liver injury resembling pediatric NAFLD. In addition, we sought to determine if a mixture of probiotics would prevent the disease. Animals were fed 1 of 4 diets containing (g/kg body weight × d) 0 g fructose, 11 g fat …

The Effects Of Providing Social And Nutritional Enrichment To Dairy Calves On Development, Behavior And Learning, Kendra Leigh Kutina

Master's Theses

The objective of this study was to measure the effects of both a nutritional (water nipple) and social (partner calf) enrichment on calf body weight, grain intake, water intake, behavior and learning. The enrichments included 1) water provided from a nipple vs. a bucket (nutritional) and 2) visual and tactile access to a partner vs. isolated rearing with no visual or tactile access to a partner calf (social). A total of 72 Holstein and Jersey dairy calves were pseudo-randomly distributed into 4 treatments at birth [Individual/Bucket (IB), Paired/Bucket (PB), Individual/Nipple (IN), Paired/Nipple (PN)]. Socially and nutritionally enriched calves drank more …