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Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine

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

Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate …

A Case For Eustress In Grazing Animals, Juan J. Villalba, Xavier Manteca

Wildland Resources Faculty Publications

Herbivores grazing in extensive systems are exposed to a series of challenges, rooted in the inherent spatial and temporal variability of their environment that potentially constrain their health, nutrition, and welfare. Nevertheless, in this review, we argue that challenges induced by some biotic (e.g., vegetation) and abiotic (e.g., terrain) factors may also be viewed as “positive” sources of stress or eustress, since they present complex problems, that when solved successfully elicit a greater degree of behavioral plasticity and adaptability in grazing animals. Chemically and structurally diverse landscapes require animals to display complex behaviors and exhibit adaptive capabilities, like building a …

Cloud Cover And Delayed Herbivory Relative To Timing Of Spring Onset Interact To Dampen Climate Change Impacts On Net Ecosystem Exchange In A Coastal Alaskan Wetland, A. Joshua Leffler, Karen H. Beard, Katharine C. Kelsey, Ryan T. Choi, Joel A. Schmutz, Jeffrey M. Welker

Wildland Resources Faculty Publications

Rapid warming in northern ecosystems over the past four decades has resulted in earlier spring, increased precipitation, and altered timing of plant–animal interactions, such as herbivory. Advanced spring phenology can lead to longer growing seasons and increased carbon (C) uptake. Greater precipitation coincides with greater cloud cover possibly suppressing photosynthesis. Timing of herbivory relative to spring phenology influences plant biomass. None of these changes are mutually exclusive and their interactions could lead to unexpected consequences for Arctic ecosystem function. We examined the influence of advanced spring phenology, cloud cover, and timing of grazing on C exchange in the Yukon–Kuskokwim Delta …

Utilizing An Electronic Feeder To Measure Mineral And Energy Supplement Intake In Beef Heifers Grazing Native Range, Kacie L. Mccarthy, Sarah R. Underdahl, Michael Undi, Stephanie Becker, Carl R. Dahlen

Department of Animal Science: Faculty Publications

Introduction

Grasslands in the Northern Plains provide the primary forage source for ruminants throughout much of the year (Schauer et al., 2004). Supplementation practices are often necessary to maintain production and offset forage nutritive decline throughout the grazing season (Schauer et al., 2004; Cline et al., 2009). Typically, to maintain a targeted production level, energy and protein supplementations are used for grazing livestock (Caton and Dhuyvetter, 1997). For developing heifers consuming low-quality forages, inclusion of energy ingredients into supplements may be beneficial for growth and reproductive performance (Schillo et al., 1992; Ciccioli et al., 2005; Cappellozza et al., 2014). In …

Examining The Capacity Of Nebraska Rangelands For Cattle Production And Evaluating Drought Management Strategies, Kaitlyn L. Cumming

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This thesis has two chapters focusing on the grazing capacity of Nebraska rangelands, and drought management strategies. The first chapter conducts a gap analysis comparing forage supplied by perennial grasslands to the animal unit months (AUMs) required by the cattle. The purpose of this research was to quantify potential AUM supply (i.e., carrying capacity) of grazing lands dominated by perennial grasses on a regional basis in Nebraska to the AUM demand based on cattle inventories and standard production practices in each region of Nebraska. The results suggest that Nebraska is operating at 100% of potential carrying capacity. Harvest efficiency for …

Is Grassfed Meat And Dairy Better For Human And Environmental Health?, Frederick D. Provenza, Scott L. Kronberg, Pablo Gregorini

Wildland Resources Faculty Publications

The health of livestock, humans, and environments is tied to plant diversity—and associated phytochemical richness—across landscapes. Health is enhanced when livestock forage on phytochemically rich landscapes, is reduced when livestock forage on simple mixture or monoculture pastures or consume high-grain rations in feedlots, and is greatly reduced for people who eat highly processed diets. Circumstantial evidence supports the hypothesis that phytochemical richness of herbivore diets enhances biochemical richness of meat and dairy, which is linked with human and environmental health. Among many roles they play in health, phytochemicals in herbivore diets protect meat and dairy from protein oxidation and lipid …

Migratory Goose Arrival Time Plays A Larger Role In Influencing Forage Quality Than Advancing Springs In An Arctic Coastal Wetland, Karen H. Beard, Ryan T. Choi, A. Joshua Leffler, Lindsay G. Carlson, Katharine C. Kelsey, Joel A. Schmutz, Jeffrey M. Welker

Ecology Center Publications

With warmer springs, herbivores migrating to Arctic breeding grounds may experience phenological mismatches between their energy demands and the availability of high quality forage. Yet, how the timing of the start of the season and herbivore arrival influences forage quality is often unknown. In coastal western Alaska, approximately one million migratory geese arrive each spring to breed, where foliar %N and C:N ratios are linked to gosling survival and population growth. We conducted a three-year experiment where we manipulated the start of the growing season using warming chambers and grazing times using captive Pacific black brant (Branta bernicla nigricans) to …

Recoupling Fire And Grazing Reduces Wildland Fuel Loads On Rangelands, Heath D. Starns, Samuel D. Fuhlendorf, R. Dwayne Elmore, Dirac Twidwell, Eric T. Thacker, Torre J. Hovick, Barney Luttbeg

Wildland Resources Faculty Publications

Fire suppression and exclusion, the historically dominant paradigm of fire management, has resulted in major modifications of fire-dependent ecosystems worldwide. These changes are partially credited with a recent increase in wildfire number and extent, as well as more extreme fire behavior. Fire and herbivory historically interacted, and research has shown that the interaction creates a unique mosaic of vegetation heterogeneity that each disturbance alone does not create. Because fire and grazing have largely been decoupled in modern times, the degree to which the interaction affects fuels and fire regimes has not yet been quantified. We evaluated effects of fire-only and …

The Effects Of Native And Domestic Grazers On The Health Of Bumble Bee (Bombus Spp.) Populations In A Historical Tallgrass Prairie Ecosystem, Mckenna Conforti

Honors Program Projects

Bumble bees (Bombus spp.) play an important role in the pollination of ecologically and economically significant plants worldwide. In recent years, bumble bee populations have suffered decline throughout North America, particularly in the Midwest. Many factors likely contribute to this decline, including the use of pesticides, disease, and habitat loss. Although cattle grazing space is a common use for Midwestern grassland, a comparison had not been made between the capacity of cattle pasture to support bumble bee communities with the capacity of tallgrass prairie, a habitat thought to be optimal for requisite floral resources. Additionally, the reintroduction of bison …