Digital Commons Network^™

Meeting Animal Needs From Mixed Grass-Legume Pastures, A J. Harris, D A. Clark

IGC Proceedings (1977-2023)

Experiments measuring plant performance and animal production from sheep at 4 climatically diverse sites in New Zealand are described. In the southern South Island grazing patterns have been developed which minimize the effect of the winter pasture production trough and make best use of the high spring/summer growth rates. High yields of animal products are achieved. In Canterbury, summer moisture stress and cool winters can have far-reaching effects on pasture and, consequently, animal performance. Use of special-purpose pastures with complementary production rhythms has allowed high productivity to be achieved in dry land. On moist North Island hill country increased stocking …

The Animal Factor In Pasture Studies, J A. Taylor

IGC Proceedings (1977-2023)

The challenge in plant-animal interface research is to derive meaningful plant-animal relationships. This paper examines some of the assumptions and bias in conventional grazing research practices. Variations within pasture and in the activity and distribution of grazing animals are important characteristics of most grazing situations. The conventional sampling strategies do not allow for the possibility that the animal perceives vegetation in a different or more subtle way than we perceive it. A more logical approach would be to seek patterns in animal activity and distribution and relate these to variations in herbage and site attributes. This approach would provide the …

Maximizing Beef Production From Irrigated Pastures With Light Weight Steers, W W. Heinemann

IGC Proceedings (1977-2023)

An experiment was designed to compare beef production by three successions of light weight steers continuous grazing two kinds of irrigated pastures. Two growth promotant ear implants were superimposed treatments in 1982. Successions of light weight steers were used in an effort to obtain maximum animal gain per ha, comparing rates of gain and gains per ha by trimesters. Average steer gains per ha from orchardgrass (Dactylis glomerata) and from perennial ryegrass (Lolium perenne) over a 4-year period were nearly the same. Average daily gains by steers that grazed perennial ryegrass were greater than by steers that grazed orchardgrass but …

Pastures And Pasture Management For High Animal Production In New Zealand, R W. Brougham, G P. Cosgrove

IGC Proceedings (1977-2023)

Limits to pasture and animal production from perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) pastures have been studied in systems experiments with fattening dairy beef bulls in the lowland Manawatu region of New Zealand. At high stocking rates the management system utilizes peak spring pasture growth and provides sufficient herbage for animals during periods of low growth in self contained, no conservation farmlets. High animal production of approximately 1000 kg of carcass meat/ha annually has been achieved. Accumulation of pasture reserves in autumn through long rotations and reductions in grazing pressure in summer through slaughter of fattened animals …

Mosaic Grazing - Animal Selectivity In Tropical Savannas Of Northern Australia, J J. Mott

IGC Proceedings (1977-2023)

In set stocked, heavily grazed, unburnt, native grass/sown legume pastures in the tropical savannas of northern Australia, animals were found to graze very selectively. This contrasts with the more uniform light grazing usually occurring in the extensive, lightly grazed native grasslands which are normally burnt annually. Once heavy selective grazing of an area was initiated, this grazing pressure was maintained, while ungrazed areas grew rank and unacceptable. Although three different sized paddocks were used to give different stocking rates, the area heavily grazed was the same at all stocking rates. In unfertilised paddocks, plants died within two years when selectively …

Influence Of Herbage Mass And Structure Of Warm-Season Grass Ingestive Behavior Of Grazing Cattle, T.D A. Forbes, S W. Coleman

IGC Proceedings (1977-2023)

An experiment was carried out to investigate the effects of herbage mass and height on cattle ingestive behavior and herbage intake, when grazing Asiatic bluestem (Bothriocloa spp.) swards. Three levels of herbage mass were maintained under continuous grazing, corresponding to 1.8, 2.0 and 4.4 t dry matter/ha. Estimates of diet in vitro organic matter digestibility, rate of biting, grazing time and intake per bite were used to calculate digestible organic matter intake (DOMI). Differences in herbage mass led to significant differences in grazing time, intake per bite and DOMI but not in diet digestibility or rate of biting. The …

Selection, Mastication, And Digestive Tract Response Of Cattle To Plant Canopy And Composition, D S. Fisher, K R. Pond, J C. Burns, R D. Mochrie, D H. Timothy

IGC Proceedings (1977-2023)

The relationship between pasture sward structure and animal intake of digestible dry matter is not well understood. To aid in developing an understanding of the plant-animal interface, flaccidgrass (Pennisetum flaccidum Griseb.) and switchgrass (Panicum virgatum L.) swards were harvested and stratified by cutting them into 5-cm layers. Strate began 5-cm above the soil and continued to the extended height of the sward. The strate were separated into leaf blade, stem, and dead material. Samples were analyzed for dry weight and in vitro dry matter disappearance {IVDMD). Esophageal sample analysis showsd steers consumed leaf material even in swards with …

The Role Of Sward Adaptations In Buffering Herbage Production Responses To Management Manipulation, S A. Grant, J King, G T. Barthram

IGC Proceedings (1977-2023)

The aim of this study is to improve understanding of sward responses to grazing manipulation so that objective guidelines for management may be provided. Rates of growth and senescence per tiller, tiller population densities and the photosynthetic efficiency of the sward canopy were measured at intervals on Lolium perenne dominated swards under contrasting management regimes involving steady-state and controlled fluctuations in sward conditions. The results suggest that the combination of changes in tiller populations, sward structure and photosynthetic efficiency and in the balance between growth and senescence per tiller act as a buffer such that net production varies little within …

Sward Utilization In Warm Season-Cool Season Grass Grazing Systems In The North-East United States, R L. Reid, G A. Jung

IGC Proceedings (1977-2023)

Grazing and behavioral trials were run over a 4-yr period to investigate use of warm season (WS) range grasses in management systems for beef cattle on marginal hill land. Grasses tested were switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), Caucasian bluestem [Bothriochloa caucasica (Trin.) C.E. Hubb.], indiangrass [Sorghastrum nutans (L.) Nash] and Plains bluestem [B. ischaemum (L.) Keng var. ischaemum]. The grasses were originally planted in pure stands and evaluated as summer pasture for yearling heifers following spring grazing on native bluegrass (Poa pratensis L. )-white clover (Trifolium repens L.). Other systems tested …

Mixed Grazing By Sheep And Cattle: Effects On Herbage Production And Utilization, J Hodgson, J C. Arosteguy, T.D A. Forbes

IGC Proceedings (1977-2023)

Two experiments were carried out to examine the effects of mixed stocking with cattle and sheep on aspects of herbage production and utilization from sown swards. On plots grazed down over three days both sheep and cattle tended to concentrate their grazing activity progressively on areas of sward previously grazed by the opposite species. Cattle were shown to be much less tolerant of cattle dung than of sheep dung, but sheep were relatively tolerant of both sheep and cattle dung. In a second study sheep and cattle were grazed alone, or in combination, on swards maintained at similar surface heights …

Animal Production Of Fattening Young Steers And Beef Cows By Precursor- Follower System On Two Pasture Types, Y Takimoto, K Nishimura, H Takeda, E Tsuneishi, T Suyama, T Mitamura, S Murasato

IGC Proceedings (1977-2023)

Animal productions were compared on two pastures, i.e. PW pasture (perennial ryegrass-white clover dominant pasture) and PO pasture (perennial ryegrass-orchardgrass dominant pasture), through precursor-follower system using feeder steers and beef cows. The experiment was carried out in 1983 and 1984. After close of grazing feeder steers were fattened for 6 or 7 months, then the carcass characteristics were examined. Feeder steers used in the experiment 1983 were born in spring and grazed for 2 seasons. And in the experiment 1984 steers were born in spring and in fall. They grazed for 2 seasons and 1 season, respectivery. By the precursor-follower …

Relations Between Nitrogen Fertilization, Herbage Production And Milk Yield, E A. Lantinga, L T'Mannetje, H Schlepers

IGC Proceedings (1977-2023)

The response to N-fertilizer of animal output and of herbage production was compared. There appeared to be no difference in the responses to applied nitrogen between intensive continuous grazing and weekly cutting in the range of 300 to 500 kg N/ha/yr. It is hypothesized that the response to applied nitrogen in a continuously grazed sward is mainly determined by the intensity of grazing and that the benefit from nitrogen circulation through excreta has little meaning for the pasture as a whole.

Modelling Grazing Intensity Studies, David I. Bransby

IGC Proceedings (1977-2023)

Grazing intensity models have traditionally related animal production per head and per ha to stocking rate. The value of such models is limited by the omission of pasture information. In this paper the relationships between average daily gain, grazing days and standing herbage are used to develop models relating animal production per ha to standing herbage. These models can also be extended by relating changes in their parameters to additional quantifiable variables, or by using them in economic models to express profit per ha in terms of standing herbage.

Grazing As A Part Of Agroforestry, Harold F. Heady

IGC Proceedings (1977-2023)

Multiple use of land by the small landholder for food crops, trees and animals, often called agroforestry, holds great promise for aiding people near poverty in developing countries, but new forages and techniques of management must be developed.

An Interdisciplinary Approach For Increasing Yield And Improving Quality Of Forages, J R. Wilson

IGC Proceedings (1977-2023)

The contribution of some basic plant disciplines, principally physiology and histology, to the improvement of pasture yield and quality is discussed. Studies of temperate pasture grasses have identified several sources of loss of potential yield and have provided selection criteria for increasing yield. Integration of this physiological research with studies of forage consumption on the same pastures is proving a valuable inter- disciplinary approach to defining management options for maximising pasture and/or animal productivity. In tropical grasses, research towards increasing total dry matter yield is perhaps unwarranted but there is need for more co-operative studies involving plant and animal scientists …

Prospects For Increasing Symbiotic Nitrogen Fixation In Temperate Grasslands, P/ Roger Ball, J R. Crush

IGC Proceedings (1977-2023)

The contribution of some basic plant disciplines, principally physiology and histology, to the improvement of pasture yield and quality is discussed. Studies of temperate pasture grasses have identified several sources of loss of potential yield and have provided selection criteria for increasing yield. Integration of this physiological research with studies of forage consumption on the same pastures is proving a valuable inter- disciplinary approach to defining management options for maximising pasture and/or animal productivity. In tropical grasses, research towards increasing total dry matter yield is perhaps unwarranted but there is need for more co-operative studies involving plant and animal scientists …

Decarbonization Is Happening In U.S. Higher Education, But Carbon Neutrality Goals Alone Are Not Delivering It, Alexander R. Barron, Nubraz F. Khan, Greta Anesko, Emma S. Larsen, Junwen Ding, Shey P. Sanges, Aaron L. Strong

Environmental Science and Policy: Faculty Publications

Carbon neutrality emerged as an overall framework for climate action several decades ago, with the assumption that institutions would follow a carbon management hierarchy - reducing their own emissions (i.e. decarbonization) and relying on high-quality offsets to address any residual emissions. In practice, offsets and other accounting-based emissions reductions have often dominated both discussion and action. However, sector-wide studies examining the balance between decarbonization and offsetting have been limited. Here, we examine 23 U.S. Higher Education Institutions (HEIs) that have declared carbon neutrality and contrast their direct (Scope 1) greenhouse gas emissions reduction efforts with a broader universe of U.S. …

Rare, Threatened And Endangered Zoology Species Of Oregon (2025), Jesse Laney, Eleanor P. Gaines, Lindsey K. Wise, Misty Nelson

Institute for Natural Resources Publications

This publication provides a 2025 update to the rare, threatened, and endangered zoology species of Oregon. Species lists are also provided in Excel format.

The Oregon Biodiversity Information Center (ORBIC) is part of the Institute for Natural Resources (INR) located at Portland State University (PSU). ORBIC maintains extensive databases of Oregon biodiversity, concentrating on rare and endangered plants, animals and ecosystems. Since its creation in 1979 as the Oregon Natural Heritage Program, ORBIC has been part of the Natural Heritage network. ORBIC is a constituent member of NatureServe, a non-profit organization with a mission to provide the scientific basis for …

Turning Waste Into Fertilizer: Aloe Vera Leaf Shavings Improve Plant Growth And Support Soil Fertility In Organic Systems, Isaiah Edward Jaramillo, Carine Cocco, James Jihoon Kang, Chu-Lin Cheng, Engil Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Aloe vera industry discards large amounts of outer leaf tissue (“shavings”), creating an opportunity to repurpose this byproduct as a sustainable fertilizer. This study evaluated whether aloe shavings can serve as a plant-based alternative to compost in organic Aloe vera production. A field trial in the Lower Rio Grande Valley of Texas tested three treatments: aloe shavings (applied to supply 39 kg N ha−1), organic compost (39 kg N ha−1), and a non-fertilized control. Laboratory incubations further assessed nitrogen mineralization and microbial respiration. Aloe shavings significantly enhanced vegetative growth: leaf number increased from 5.7 to 12.3 leaves per plant …

Eutrophication, Hope Northagen, Sarah Erwin, Ethan Gilliam

All Current Publications

Eutrophication refers to the ecological state of a water body after excessive nutrient pollution. The external introduction of nutrients (primarily nitrogen and phosphorus) accelerates the growth and reproduction of plants, algae, and microbes. This fact sheet explains where eutrophication comes from, its impacts, how it is treated, and what you can do to help restore and protect our lakes, rivers, and oceans.

Needs Analysis Of Interactive Learning Media For Teachingheat Transfer In Physics: Students’ And Teachers’Perspectives, Rizki Eka Shintya, Ika Mustika Sari, Ida Kaniawati

Jurnal Pendidikan Sains

Heat transfer material in physics is known to be abstract. This study specifically analyzes the conceptual difficulties, and visualization needs specific to this material, which is different from the analysis of physics needs in general. This analysis does not only look for the need for traditional media but explicitly looks for the need for interactive media (simulation, animation, virtual laboratory). Therefore, this study aims to identify the need for interactive learning media in physics education, specifically in the teaching of heat transfer, from the perspective of students and teachers in West Java, Indonesia. Using a quantitative descriptive survey, data were …

Skin Cancer Image Classification Using Deep Learning With Data Segmentation Technique, Akhilesh Kumar Shrivas, Hema Vastrakar

Karbala International Journal of Modern Science

The human skin is an impressive organ and structural element often impacted by a diverse range of recognized and unknown diseases. Diagnosing disorders that affect the outermost layer of the body is the most uncertain and difficult component in the scientific field. Dermatological diseases are one of the most significant health concerns in the 21st century since their identification is challenging and costly, plagued with challenges and the subjectivity that comes with human interpretation. The main objective of this piece of research work is to develop a robust model for the classification of skin cancer diseases using deep convolution neural …

Development Of Natural Product Analogs As Therapeutic Agents, Jacob Mara

Theses and Dissertations

Cancer stem cells (CSC) are cancer cells in a tumor mass that may self-renew and develop into various cell types, resulting in a heterogeneous tumor. CSCs have been shown to have a role in many facets of cancer formation, including tumor genesis, proliferation, and metastatic activity. They are also implicated in chemotherapeutic treatment resistance and the recurrence of some malignancies. Based on these capacities, CSCs have been identified as the next target for cancer therapy and control. Salinomycin's potential for therapeutic use based on ongoing research, as well as the synthesis of its derivatives and their biological activity, will also …

Discriminative Accuracy Of Cha2ds2-Vasc Score, And Development Of Predictive Accuracy Model Using Machine Learning For Ischemic Stroke Risk In Cardiac Amyloidosis And Atrial Fibrillation, Waqas Ullah, Abhinav Nair, Eric Warner, Salman Zahid, Mansoor Rahman, Palwasha Khan, Indranee Rajapreyar, Sridhara S. Yaddanapudi, M. Chadi Alraies, Said Ashraf, Jeffery Van Hook, Yegeny Brailovsky

Department of Medicine Faculty Papers

BACKGROUND: CHA2DS2-VASc score in cardiac amyloidosis (CA) with atrial fibrillation (AF) is believed to underestimate ischemic stroke risk, necessitating a better predictive model.

METHODS: Data were obtained from the National Readmission Database (NRD). Outcomes between CA-AF and no-CA-AF were compared using multivariate regression analysis to calculate adjusted odds ratios (aORs). AutoScore, an interpretable machine learning framework, was used to develop a stroke risk prediction model, and its predictive accuracy was evaluated with an area under the curve (AUC) using the receiver operating characteristic analysis.

RESULTS: A total of 11,860,804 (CA-AF 22,687 (0.19%) and no-CA-AF 11,838,117) patients were identified from 2015 …

Factors Influencing Plant Community Structure And Composition Of Restored Tamaulipan Thornscrub Forests, Jerald T. Garrett, Audrey J. Hicks, Christopher A. Gabler

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Lower Rio Grande Valley (LRGV) of Texas is a biodiversity hotspot due to its high alpha, beta, and gamma diversity and high regional endemism, which are at high risk of degradation. The region has lost 95% of its native thornforest habitat primarily due to agricultural and urban expansion. This study aims to evaluate the current vegetative structure and composition of restored thornforest sites located in the LRGV to identify restoration methods and site characteristics that affect forest restoration outcomes. Twelve restored thornforest sites were selected for this study that varied in time since restoration, patch size, degree of isolation, …

Lagomorph Spotlight Survey Results, Johan Du Toit, Shantell Garrett

Browse all Datasets

Results of lagomorph spotlight surveys conducted in the foothills of the Henry Mountains, south-central Utah, over 2014-2022.

Scientific Authority In The Public Sphere: The Heroic Legacies Of Carl Sagan And Philip Zimbardo, Scott T. Allison

Heroism Science

This article examines the parallel trajectories of Carl Sagan and Philip Zimbardo as scientists who assumed the role of public intellectuals. Their careers highlighted the tensions and opportunities inherent in bridging scholarly research and public engagement. Sagan, an astronomer, popularized the cosmic perspective to promote planetary stewardship, while Zimbardo, a social psychologist, used compelling methodologies to explore the psychological underpinnings of cruelty and heroism. Both were, in their own ways, heroic in their commitment to making science accessible, employing storytelling and mass media to render complex concepts understandable and relevant, thereby expanding the societal relevance of their disciplines. However, their …

The Effects Of Plastic Mulch And Irrigation On Hemp Chemistry And Leaf Endophytes, Allison Rietman, Connor Morozumi, Robert C. Pearce, Natalie Christian

Journal of Agricultural Hemp Research

As an emerging crop, cultivation techniques for industrial hemp (Cannabis sativa L.) are still being developed and optimized. For example, irrigation and plastic mulching are some management practices that have been touted for their benefits in improving crop quality. Both techniques ensure ample water availability, which has often been attributed to improving hemp cannabinoid and terpene composition. In this study, we examined how supplemental irrigation implemented in a plastic mulch system influenced the cannabinoid and terpene profiles of one cultivar of CBD hemp, Lifter. We grew industrial hemp in field with plastic mulch and applied regular irrigation to one group …

Growth Mindset In The Mathematics Classroom: Studying The Effects Of A Growth Mindset Intervention On High School Students In A Geometry Classroom, Katelyn Strauss

Mathematics Graduate Theses

Having a growth mindset is crucial to being successful in a mathematics classroom. However, many students believe themselves to be either “mathematics people” or “not mathematics people”. When students believe they are not a mathematics person, they are far less likely to engage in material where they face struggles, and thus they miss out on valuable learning. A review of the literature has show that students have been able to shift their mindset from fixed to growth through a series of interventions. I used a unit in Geometry to see how a growth mindset intervention would affect the mindset of …

Phosphate Removal And Recovery From Aqueous Solutions Using Iron-Coated Steel Slag, Siavash Ebrahimzadeh, Guanghui Hua, Christopher Schmit

Civil and Environmental Engineering Faculty and Student Publications

Phosphate pollution from human activities significantly contributes to the eutrophication of aquatic ecosystems. Additionally, phosphorus is a finite, irreplaceable resource, making its management and recovery critical. This study explores the use of iron-coated steel slag (ICS) as a cost-effective material for phosphate removal and recovery from water. Ferric chloride was used to coat electric arc furnace slag via oven drying under various conditions. Batch adsorption tests evaluated phosphate adsorption, and the optimum coating conditions were identified as 0.5–1 mm slag, 0.5 M FeCl₃, and coating pH 1. The effect of solution pH and coexisting ions on phosphate removal were also …