Life Sciences Commons^™

Effect Of Substrate Dispersion Method And Particle Size On In Vitro Digestibility, Gas Production Kinetics And Composition, And Fermentation Characteristics In Different Feed Types, Luiz C. O. Sousa, Ellem M. A. Matos, Ronald J. Trotta, Edenio Detmann, David L. Harmon

Animal and Food Sciences Faculty Publications

Our objective was to evaluate the influence of substrate dispersion method and particle size on in vitro digestibility, gas production kinetics and composition, and fermentation characteristics of different feed types. Alfalfa hay, tall fescue hay, ground corn, soybean meal, and a total mixed ration (TMR) were used as substrates. Treatments were designed according to a 2 × 2 × 5 factorial arrangement: two substrate dispersion methods (loose substrate and in filter bags), two particle sizes (1 mm and 2 mm), and five feeds. Filter bags decreased (P ≤ 0.001) digestibility and gas production compared with loose samples. Filter bags decreased …

Comparison Of Enrichment Interaction Duration Between Male And Female Panthera Leo Leo, Maegen G. Meldrum

Undergraduate Honors Thesis Projects

African lion (Panthera leo leo) populations have declined significantly over the past century within their natural habitats, increasing the importance of effective management strategies for individuals in human care. Environment enrichment is a critical tool for promoting species typical behavior in human care; however, enrichment practices are often generalized and may not account for sex-specific differences. This study examined how sex, enrichment types, behaviors, and time of day influenced enrichment interaction duration in a small pride of African lions (n = 4) housed at the Columbus Zoo and Aquarium. Two enrichment types were evaluated: cognitive/occupational (CO, a manipulable barrel) …

Taxonomy, Distribution And Ecology, Biology, Nutritional Composition, And Conservation Status Of Critically Endangered Lake Chala Tilapia Oreochromis Hunteri (Günther, 1889): Implications For Aquaculture Development, Jonathan Munguti, Mavindu Muthoka, Domitila Kyule, Esther Magondu, Jacob O. Iteba, Kevin Obiero, Paul Orina, Menaga Meenakshisundaram, Tanga M. Chrysantus

All Peer-Reviewed Publications

Oreochromis hunteri Günther, 1889, commonly known as Lake Chala tilapia, is an endemic cichlid restricted to the small crater lake, Lake Chala, on the border of Kenya and Tanzania. This review synthesizes existing knowledge on the taxonomy, and phylogenetic placement, distribution and ecology, and biology including nutritional composition, and conservation status of O. hunteri and identifies knowledge gaps to assess its potential for aquaculture development. The knowledge gaps include its reproductive biology, population structure, and adaptive capacity to environmental and climatic variability. As the type species of the genus Oreochromis, O. hunteri is a unique, genetically isolated lineage within a …

Do California Rangeland Healthy Soil Practices Offer Co-Benefits For Grassland Birds?, Ximena O. Gil

Cal Poly Humboldt theses and projects

Rangelands are important landscapes in California that support a robust cattle industry and serve as vital grassland habitat for birds. Climate change is projected to impact rangelands, leading to economic and ecological deterioration. In California, the Healthy Soils Program (HSP) incentivizes climate-smart solutions to increase working land resiliency. While the HSP targets soil and range health for livestock, it may also benefit birds. We surveyed rangeland operators to examine whether the implementation and duration of specific range management practices, such as range seeding, prescribed grazing, and silvopasture, are associated with bird community responses, using avian point count data from Point …

Letter From The Dean, Jeff Edwards

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Instructions For Authors, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

The Conservation Value Of Silvicultural Systems For Breeding And Post-Fledging Bird Communities In Northeastern North America, Christopher Andrew Liazos

Antioch University Dissertations & Theses

Forest bird community decline in the eastern United States is partly due to the lack of early-and-late-successional forests stemming from historic land use. Silviculture can create underrepresented forest age classes and structures to support avian communities during the breeding and post-fledging periods. In southwestern New Hampshire, we conducted a case study evaluating avian conservation value indices across silvicultural systems. Our goal was to observe how avian conservation value indexes and abundance differed between recently managed and unmanaged stands. We surveyed 215 breeding and 118 post-fledging points across 22 sites using point counts and vegetation surveys. Conservation values in the breeding …

Geographic Distribution: Pseudacris Sierra (Sierran Treefrog). Usa: Florida: Escambia Co., Justin A. Anto, Logan P. Cutts, Jakira A. Davis, Dyrana N. Russell, Renee M. Shiska, Kayla L. O. Walker, Louis A. Somma

Papers in Herpetology

No abstract provided.

Microbial Mats In Dinosaur Ichnocoenoses, Nora Noffke, Paul C. Murphy, Roger C. Buntin, Martin G. Lockley

OES Faculty Publications

Until now, the significance of microbial mats in preservation of dinosaur tracks and in reconstructing the palaeoenvironment in which dinosaurs roamed was rarely studied. Dinosaur tracks are commonly found close to ancient aquatic bodies where moist sediment had once allowed footstep registration. At such sites, epibenthic or endobenthic microbial mats may have developed as well and may have led to exquisite track preservation. Microbial mats in coastal, lacustrine or flood plain environments cause 'microbially induced sedimentary structures—MISS', which are micobialites found in sandy or evaporitic settings. The microbial structures record environmental parameters including meteorological conditions that existed at the time …

Oligonychus Trichardti (Acari: Tetranychidae) Associated With Urochloa Grasses In Kenya: An Integrative Taxonomic Approach, Paula Espitia-Buitrago, Claudia Perea, Lavender A. Odhiambo, Rosa N. Jauregui, Frank Chidawanyika

All Peer-Reviewed Publications

Spider mites represent a significant constraint to improved forage grass adoption in East Africa, particularly affecting Urochloa cultivars that are crucial for addressing the region’s 40% livestock feed gap. This study employed an integrative taxonomic approach combining morphological and molecular analyses to identify a spider mite species infesting Urochloa interspecific grasses in Kenya. A colony of 80 spider mites was established from symptomatic Urochloa hybrid cv. Cayman plants collected from Mbita Point, Kenya, showing characteristic foliar chlorosis and necrotic spots. Morphological examination of 46 slide-mounted specimens using Hoyer’s medium revealed consistent morphotypical features characteristic of Oligonychus (Reckiella) trichardti Meyer, 1974. …

Crab And Lobster Shell Meal Taste Preferences Of Dairy Heifer Calves, Summer R. Pescinski, Peter S. Erickson

Honors Theses and Capstones

Objective: This preference study was conducted to evaluate the palatability of crab shell meal (CM) and lobster shell meal (LM) when added to calf starter for post-weaned dairy heifer calves.

Materials and methods: Six calves were used for a sequential elimination experiment to rank their taste preferences when offered control calf starter, calf starter mixed with 50 g of CM, and calf starter mixed with 50 g of LM.  The calves were kept on the study for a total of 5-d split into two feeding segments.  Preference was determined by calculating the total intake of each treatment …

Effects Of Perching Behavior In Broilers On Welfare And Production Benefits, Natalie G. Bunn

Honors Theses and Capstones

Broiler chickens are bred for feed efficiency, rapid growth rate, and muscle development. Conventional broiler farms utilize fast-growing breeds that reach market weight rapidly and present welfare concerns. Primarily raised indoors with little enrichment, the genetics and husbandry practices of broilers encourage inactivity and perpetuate health problems such as skeletal deformities, lameness, and pododermatitis. Despite the commonness of these issues, there is little research on the reduction of such health complications through production management. This study investigated methods to promote perching behavior and the effects of riser perch and platform perch utilization in broilers. A mixed flock of slow-growing Gray …

Miscellaneous Notes On Terrestrial Gastropods (Mollusca: Gastropoda) Of Seven Superfamilies Represented In Bhutan, With Two New Genera And Two New Species, Edmund Gittenberger, Sherub, Choki Gyeltshen, Nima Dorji, Kezang Tobgay

Research outputs 2022 to 2026

The species incorrectly referred to as Tropidophora spec. by Gittenberger et al. (2017, A field guide to the common molluscs of Bhutan: 42, fig. 27) is identified as Lagocheilus tomotrema (Benson, 1857). It is known from southern Bhutan, below 2000 m a.s.l. In fresh specimens the periostracum bears spiny or flattened, hitherto overlooked, stalked protrusions. Two species of Veronicellidae are reported as new for Bhutan. One of these was identified by a dna analysis as the pest species Laevicaulis alte. The second species could not be identified. Curvella sikkimensis is reported as new for Bhutan, where it was recorded in …

Biomarkers Of Foraging And Reproduction In Captive Adult Female Hawksbill Sea Turtles (Eretmochelys Imbricata), Joslyn Blessing Kent, Kari Renee Dawson, Shingo Fukada, Masae Makabe, Isao Kawazu, Ken Maeda, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hawksbill sea turtles (Eretmochelys imbricata) are listed as critically endangered by the International Union for the Conservation of Nature (IUCN). To implement best conservation practices for this species, its biology should be well understood. Attempting to characterize the foraging physiology of free-ranging hawksbill sea turtles is complicated by the fact that sampling is typically limited to nesting females during the reproductive season. Without data from non-reproductive periods, it is difficult to determine whether observed physiological values reflect baseline conditions or are specific to the energetically demanding nesting season. Accordingly, in this study, we described the physiology of foraging in …

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 27 2026, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Cross-Domain Antimicrobial Resistance In Poultry Farming: A One Health Assessment Of Antimicrobial Use And Multidrug Resistance In Kiambu County, Kenya, Ann Kangai Munene, Peter Muiruri Mwangi, Lilly Caroline Bebora, Christine Minoo Mbindyo, John Muthini Maingi

All Peer-Reviewed Publications

Background and Aim: Antimicrobial resistance (AMR) has emerged as a major One Health threat driven by inappropriate antimicrobial use (AMU) in humans, animals, and the environment. Poultry production is recognized as a key reservoir of antimicrobial-resistant bacteria, yet few studies in Kenya examine AMU and AMR across interconnected human–animal–environment domains. This study assessed AMU patterns among poultry farmers in Kiambu County and characterized phenotypic resistance in Escherichia coli and Enterococcus spp. isolated from humans, chickens, and chicken environments. Materials and Methods: A cross-sectional study was conducted from May to September 2024, involving 102 poultry farms. Farm demographics and AMU data …

Behavior Of A Komodo Dragon In Relation To Whole-Prey Feeding, Gurkiran Kaur Natt

Williams Honors College, Honors Research Projects

In zoological settings, whole-prey feeding is an enrichment strategy widely used to prompt naturalistic behaviors; yet, the specific behavioral shifts this causes in reptiles are not well-documented. This study focused on the activity budgets and spatial use of a six-year-old male Komodo dragon (Varanus komodoensis) housed at the Akron Zoo, analyzing his movements in direct response to whole-prey feeding sessions. Over an eight-week observation period, instantaneous scan sampling was utilized to quantify behaviors before and after two distinct whole-prey feeding sessions. Although active behaviors and "not visible" instances increased marginally post-feeding, paired t-tests confirmed these shifts were not statistically significant …

Foundations For Trojan-Y Chromosome Development In Sacramento Pikeminnow (Ptychocheilus Grandis): A Novel Strategy For Invasive Species Management In The Eel River, Ca, Raven Mcadams

Cal Poly Humboldt theses and projects

The Sacramento Pikeminnow (Ptychocheilus grandis), an invasive predator in California’s Eel River, contributes to predation pressure on native salmonid populations despite ongoing suppression programs. This study assessed the feasibility of hormonal sex reversal as an initial step toward implementing the Trojan Y Chromosome (TYC) strategy as a novel tool for managing invasive Sacramento Pikeminnow populations in the Eel River, CA. Objectives were to 1) determine the size when gonadal differentiation occurs 2) identify an effective estradiol dosage for producing phenotypic XY females, and 3) identify sex-reversed fish using a sex-specific genetic marker.  Histological examination of juvenile fish was …

Coho Salmon (Oncorhynchus Kisutch) Response To Habitat Restoration Through Space And Time: Monitoring Growth, Survival, And Movement In A Restored Habitat Network, Carter Perez Adamson

Cal Poly Humboldt theses and projects

Despite the decline of coho salmon (Oncorhynchus kisutch), Prairie Creek, a tributary of Redwood Creek in northern California, remains a coho salmon stronghold. The restoration of juvenile coho rearing habitat was identified as a recovery objective in this watershed by the National Marine Fisheries Service. Among the restoration projects addressing this objective are an ongoing project on Prairie Creek and its tributary Skunk Cabbage Creek, and a prior effort on Strawberry Creek (a tributary of Redwood Creek’s estuary). Standard monitoring methods for assessing project success have limitations and may be improved by measuring salmon use of restored habitats …

Integrating Multi-Method Monitoring To Characterize Seasonal Habitat Use Of Green Sturgeon (Acipenser Medirostris) In Humboldt County, California, Olivia S. Boeberitz

Cal Poly Humboldt theses and projects

Green sturgeon (Acipenser medirostris) are a long-lived, anadromous, iteroparous species that spawns in large West Coast North American rivers but ranges widely in the coastal ocean. For coastal California Native American Tribes, green sturgeon are a vital part of their cultural heritage and traditions, and central to their food security. Two genetically distinct population segments (DPSs) of green sturgeon are recognized in the United States, Canada, and Mexico; the southern DPS is listed as “threatened” under the Endangered Species Act and the northern DPS is considered of “conservation concern.” Although green sturgeon are known to use large estuaries …

Evidence Of Personality And Movement Syndromes In A Mobile Predator: How Individual Hunting Strategy Shapes Ecosystem Service Potential By Barn Owls (Tyto Furcata) In An Agroecosystem, Lauren M. Jackson

Cal Poly Humboldt theses and projects

Animal-mediated ecosystem services are delivered through the behavior of individuals, yet most studies evaluate service-providing species at the population level. We tested whether individual variation in plumage, behavior, and movement predicted hunting behavior and vineyard habitat use by adult male American barn owls (Tyto furcata) nesting in winegrape vineyards in Lodi, California, USA. We fitted GPS-accelerometer tags to 42 breeding males, quantified breast-plumage traits, measured neophobia using repeated novel object tests, and derived nightly movement metrics from GPS tracks and hidden Markov model-classified hunting locations. Several behavioral traits were repeatable, but movement traits showed the clearest repeatable individual …

Multiple Burn And Forest Characteristics Affect Gray Fox (Urocyon Cinereoargenteus) Occurrence Following A California Megafire, Amida Zohar Verhey

Cal Poly Humboldt theses and projects

In western North American forests, predator communities are faced with changing fire regimes and increased fire severity and size, particularly with megafires (>10,000 ha). As some wildlife communities may restructure following the loss of apex consumers, understanding post-fire space use of mid-trophic carnivores may inform species composition in these forests. I compared gray fox (Urocyon cinereoargenteus) occupancy in and around the 2021 Dixie Fire, the largest single-ignition fire in California state history, to examine which spatially variable burn and forest characteristics affected the space use of a widespread generalist mesopredator. Using 210 camera traps placed in 2023, …

Management And Nutrition Factors That Impact Broiler Breeder Fertility, Jeanna Wilson

Proceedings of the Arkansas Nutrition Conference

This article addresses the recent decline in broiler breeder hatchability.  Both managerial and nutritional solutions for mitigating the decline in hatchability are discussed.

Rethinking Macro And Micro Mineral Formulation In Modern Broilers, K. M. Venter, A. Herbst, P. W. Plumstead

Proceedings of the Arkansas Nutrition Conference

These proceedings discuss factors that affects calcium, phosphorus, zinc, and copper availability in poultry diets. Furthermore, the role of phytate and phytase on availability of the nutrients and their dietary requirements is investigated.

Engineering Broiler Efficiency Through Modern Infrastructure Design And Precision Control, Chris Travers

Proceedings of the Arkansas Nutrition Conference

These proceedings describe a modern, innovative broiler site in South Africa constructed with the following objectives in mind: Scale, Energy Efficiency, Precision Environmental Control with AI Integration, and Off-Grid Power Autonomy.

Renal And Gastrointestinal Disturbances That Cause Wet Manure And Litter In Poultry: Non-Nutritional And Nutritional Interventions To Prevent And Control The Issues, Fausto Solís

Proceedings of the Arkansas Nutrition Conference

These proceedings represent a broad overview of wet litter causes and management.  Both the impact on bird health and fertilizer management are discussed.  In addition to nutritional factors that impact litter quality, these proceedings address poultry health from disease implications of wet litter.

Precision Broiler Nutrition: Bioeconomic Optimization Of Broiler Feeds With A Focus On Balanced Protein (Bp) And Metabolizable Energy (Me), Shivaram K. Rao, Rocky Latham, Phillip Smith, Hunter Walters, Malea Frank, Alejandro Corzo

Proceedings of the Arkansas Nutrition Conference

Key broiler performance indicators in live performance and yields are impacted by precision nutrition, and more specifically balanced protein and energy.  These proceedings deal with bioeconomic optimization of broiler performance using profit scenarios like income over feed costs.

Soybean Meal Quality: Key Quality Control Parameters And Current Recommended Thresholds For In Vitro Assessments, Benjamin Parsons

Proceedings of the Arkansas Nutrition Conference

These proceedings review the anti-nutritional factors of soybean meal and its resultant quality.  Numerous in vitro assays are discussed herein.  Recommendations from data on the most robust assays to assess both under and overprocessing of soybean meal are discussed.

Does Phytase Change How We Feed Breeders?, Wenting Li

Proceedings of the Arkansas Nutrition Conference

Dietary evaluation of the use of exogenous phytase has received considerable attention in broilers, but not broiler breeders.  Moreover, the limited studies that have assessed phytase in broiler breeders are dated, which makes interpretation problematic because dated phytase enzymes are not as efficacious as current phytase enzymes.  The article addressed practical applications for dietary phytase in broiler breeder diets.