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2020

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Articles 2791 - 2820 of 3204

Full-Text Articles in Earth Sciences

Evaluation Of Forage Quality Indicators Using Multivariate Methods (Case Study: Rangelands Of Karsanak, Chaharmahal Va Bakhtiari Province), Hassan Yeganeh, Hossein Arzani, Javad Motamedi, Hamze Ali Shirmardi, Ehsan Zandi Esfahan Jan 2020

Evaluation Of Forage Quality Indicators Using Multivariate Methods (Case Study: Rangelands Of Karsanak, Chaharmahal Va Bakhtiari Province), Hassan Yeganeh, Hossein Arzani, Javad Motamedi, Hamze Ali Shirmardi, Ehsan Zandi Esfahan

IGC Proceedings (1977-2023)

In most studies on forage quality, the rank of species and the interaction effect between species and time (grazing months) has not been analyzed for forage quality (Meshkani 1986). An additive main effect and multiplicative interaction (AMMI) model is able to analyse the interaction of species in the environment. Studies on stability of forage production have been carried out using the AMMI model (Farshadfar et al. 2010).

The objective of the current research was to determine the forage quality indicators of range species through AMMI models in semi-steppe rangelands of Karsanak area of Iran.


Effect Of Enclosure And Open Grazing On Diet Selection, Relative Preference Index And Voluntary Intake By Sheep At El-Khuwei Locality North Kordofan State Sudan, Mohammed Abdelkreim, Babo Fadlalla Jan 2020

Effect Of Enclosure And Open Grazing On Diet Selection, Relative Preference Index And Voluntary Intake By Sheep At El-Khuwei Locality North Kordofan State Sudan, Mohammed Abdelkreim, Babo Fadlalla

IGC Proceedings (1977-2023)

The nutritive value of a pasture depends mainly on its in-take and the selection animals exert in consuming the different species or the various parts of a determined plant (Mayes and Dove 2000). Animal production in North Kordofan State is mainly traditional depending on natural rangeland (Cook and Fadlalla 1987; DHP 1998). The State is rich in animal and range resources. It contains more than 13 million head of sheep, goats, camels and cattle (IFAD 2011).

The study aims to provide information that contributes to a better understanding of the plant-animal inter-actions through knowledge of diet botanical composition, forage biomass …


Nutrition Diet Of Grazing Sheep And Forage Supply On Natural Grassland, Guomei Yin, Yingjun Zhang, Yongzhi Liu, Zhijun Wei, Heping Zhao Jan 2020

Nutrition Diet Of Grazing Sheep And Forage Supply On Natural Grassland, Guomei Yin, Yingjun Zhang, Yongzhi Liu, Zhijun Wei, Heping Zhao

IGC Proceedings (1977-2023)

Forages are a major asset of any livestock operation and the foundation of most rations in a forage-based livestock system. The available nutrients in a forage influence individual animal production (e.g. gain per animal), while the amount of forage produced affects production per hectare. The relationship between voluntary food intake and animal productivity is well recognized. Many studies related to the regulation of food consumption by sheep and cattle have been reported (Provenza 1996). Willoughby (1958) dis-cussed a number of factors which might influence the herbage intake of grazing animals. By contrast, less attention has been given to …


Potential Of Near-Infrared Reflectance Spectroscopy (Nirs) To Predict Nutrient Composition Of Bromus Tomentellus, Hossein Arzani, Anvar Sour, Javad Motamedi Jan 2020

Potential Of Near-Infrared Reflectance Spectroscopy (Nirs) To Predict Nutrient Composition Of Bromus Tomentellus, Hossein Arzani, Anvar Sour, Javad Motamedi

IGC Proceedings (1977-2023)

Near-infrared reflectance spectroscopy (NIRS) was used to analyse the nitrogen (N), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolizable energy (ME) content of three phenological stages (vegetative, flowering and seeding) of Bromus tomentellus samples in grazing pastures of Iran. The sample set consisted of 40 samples for calibration and 23 samples for validation was used to predict N, ADF, DMD and ME, separately. The samples were measured by reflectance NIR in a 950-1650 nm range. Calibration models between chemical data and NIR spectra were produced using the method of partial least squares (PLS). The coefficients of determination (R2) …


Trace Element Imbalance In Vegetation As A Threat To Free Ranging Cattle In The Gilgel Gibe Valley, Ethiopia, Thomas Van Hecke, Veronique Dermauw, Kechero Yisehak, Gijs Du Laing, Luc Duchateau, Geert P. J. Janssens Jan 2020

Trace Element Imbalance In Vegetation As A Threat To Free Ranging Cattle In The Gilgel Gibe Valley, Ethiopia, Thomas Van Hecke, Veronique Dermauw, Kechero Yisehak, Gijs Du Laing, Luc Duchateau, Geert P. J. Janssens

IGC Proceedings (1977-2023)

As in many tropical countries, natural pastures are the main source of nutrients for cattle in Ethiopia. However, there is limited information available with regard to trace element concentrations in Ethiopian forages. In this study, 58 plants were sampled in the Gilgel Gibe valley based on the observed ingestion by zebu cattle (Bos indicus) herds, grazing at different elevation and soil types, and analysed for copper (Cu), cobalt (Co), iron (Fe), molybdenum (Mo), manganese (Mn), sulfur (S), selenium (Se) and zinc (Zn). The effect of elevation, soil type and plant type on the above trace element concentrations was …


Variations An Α-Tocopherol And Β-Carotene Concentrations In Forage Legumes And Grasses Harvested At Different Sites And Maturity Stages, Elisabet Nadeau, Hanna Lindqvist, Søren Krogh Jensen, Nilla Nilsdotter-Linde, Anne-Maj Gustavsson Jan 2020

Variations An Α-Tocopherol And Β-Carotene Concentrations In Forage Legumes And Grasses Harvested At Different Sites And Maturity Stages, Elisabet Nadeau, Hanna Lindqvist, Søren Krogh Jensen, Nilla Nilsdotter-Linde, Anne-Maj Gustavsson

IGC Proceedings (1977-2023)

Forage is a major source of natural α-tocopherol and β-carotene for dairy cows. This study examined vitamin concentrations of birdsfoot trefoil (Bft), red clover (Rc), timothy (Ti) and meadow fescue (Mf) at different sites, years and cutting dates. Mixtures of Bft+Ti, Rc+Ti and Rc+Mf were established at Skara (58°21’N; 13°08’E) and Umeå (63°45’N; 20°17’E) in Sweden. First-year leys were cut on three occasions in spring (Umeå 2005, Skara 2005 and 2007); one week before heading of timothy, at heading and one week after heading. Birdsfoot trefoil had higher α-tocopherol concentration at Skara than at Umeå in the first two cuts …


Comparing Drying Protocols For Perennial Ryegrass Samples In Preparation For Chemical Analysis, Marion Beecher, Deirdre Hennessy, Tommy M. Boland, Michael O’Donovan, Eva Lewis Jan 2020

Comparing Drying Protocols For Perennial Ryegrass Samples In Preparation For Chemical Analysis, Marion Beecher, Deirdre Hennessy, Tommy M. Boland, Michael O’Donovan, Eva Lewis

IGC Proceedings (1977-2023)

Diet formulation for animals requires accurate estimation of feed nutritive value. In order to determine the nutritive value of grass, the moisture in the samples must be removed, with minimum damage to cell structure, and then the dried samples milled, prior to chemical analysis. Generally samples are oven dried. The aim of this study was to verify if differing drying protocols gave diverging results when drying grass samples. The drying protocols investigated were 40°C for 48 hours, 60°C for 48 hours and 95°C for 15 hours in forced convection ovens. Four perennial ryegrass samples were cut to 4 cm from …


Remote Sensing Of Pasture Quality, Reddy R. Pullanagari, Robyn A. Dynes, Warren M. King, Ian Yule, Susanne Thulin, Nichola M. Knox, Abel Ramoelo Jan 2020

Remote Sensing Of Pasture Quality, Reddy R. Pullanagari, Robyn A. Dynes, Warren M. King, Ian Yule, Susanne Thulin, Nichola M. Knox, Abel Ramoelo

IGC Proceedings (1977-2023)

Worldwide, farming systems are undergoing significant changes due to economic, environmental and social drivers. Agribusinesses must increasingly deliver products specified in terms of safety, health and quality. Increasing constraints are being placed on them by the market, the community and by government to achieve a financial benefit within social and environmental limits (Dynes et al. 2003).

In order to meet these goals, producers must know the quantity and quality of the inputs into their feeding systems, be able to reliably predict the products and by-products being generated, and have the skills to be able to manage their business accordingly. …


Infrastructure To Improve Beef Business Outcomes In The Queensland Gulf, Kiri C. Broad, Bernie H. English, Rebecca A. Gunther, Emma S. Hegarty, Joe W. Rolfe, Steven G. Bray Jan 2020

Infrastructure To Improve Beef Business Outcomes In The Queensland Gulf, Kiri C. Broad, Bernie H. English, Rebecca A. Gunther, Emma S. Hegarty, Joe W. Rolfe, Steven G. Bray

IGC Proceedings (1977-2023)

There are significant economic and environmental issues impacting on the short and long term viability of family-run breeding enterprises in the Queensland Gulf. Falling cattle prices and increased business costs threaten the social and financial well-being of many beef producers. Set stocking and overgrazing combine to reduce native 3P (productive, palatable and perennial) grass frequency and herd productivity. The Ryan family on Greenhills Station at George-town in the Queensland Gulf embarked on a 5 year water and fencing infrastructure development program aiming to improve pasture utilisation, land condition and long term carrying capacity.


A Technique For Measurement Of Cattle Form Using A Trail 3d Digital Camera, Tamaki Kida, Shigeki Tejima, Toshitaka Uchino, Fumihiko Tanaka Jan 2020

A Technique For Measurement Of Cattle Form Using A Trail 3d Digital Camera, Tamaki Kida, Shigeki Tejima, Toshitaka Uchino, Fumihiko Tanaka

IGC Proceedings (1977-2023)

Measurement of weight and form are important for the management of grazing cattle; however, form measurement is seldom carried out. Recently, use of 3D digital cameras has been increasing, and 3D-technology for reconstruction of 3D pictures has been developed. The measurement of withers and hip height of cattle from 3D pictures using the image-analysis technique has been reported (Kida et al. 2012). However, time and effort are required to obtain 3D images of grazing cattle in pastures.

Here, we examined an automatic photographic technique using a sensor camera.


Modelling Complex Sheep Systems Using Ausfarm, Susan M. Robertson, Michael A. Friend Jan 2020

Modelling Complex Sheep Systems Using Ausfarm, Susan M. Robertson, Michael A. Friend

IGC Proceedings (1977-2023)

Simulation modelling can be a valuable method for extrapolating experimental findings to different weather or management conditions. However, most of the decision support tools which are available for sheep grazing systems, for example GrassGro® (Donnelly et al. 1997), are limited to modelling of relatively simple sheep management. This makes validation of simulations against experimental results difficult where management changes from year to year, and where more complex sheep management is used. This study evaluated the use of the AusFarm® decision support tool (Moore et al. 2007) to model a split-joined sheep system, using different ram breeds against experimental …


Does Targeted Short-Term Grazing Of Lucerne Increase Twinning Rates In Unsynchronised Merino Ewes?, Jessica M. Rummery, Susan M. Robertson, Belinda J. King, Michael A. Friend Jan 2020

Does Targeted Short-Term Grazing Of Lucerne Increase Twinning Rates In Unsynchronised Merino Ewes?, Jessica M. Rummery, Susan M. Robertson, Belinda J. King, Michael A. Friend

IGC Proceedings (1977-2023)

Reproduction is one of the key profit drivers in the sheep industry and increased reproductive output is needed to address the decline in sheep numbers in Australia to maintain supply to export markets (Curtis 2009). Increased nutrition around mating, or ‘flushing’, is a well-known means of increasing twinning rates. Studies using synchronisation methods have shown that short-term (acute) supplementation can increase prolificacy if targeted at days 9-14 of the oestrous cycle (Stewart and Oldham 1986). However, synchronisation involves increased chemical and labour costs, so may not suit extensive production systems. This study aimed to test whether an increase in twinning …


Evaluating Rangeland's Grazing Capacity For Livestock And Wild Herbivores Using The Delta Diet Tool And Gis Technology, Sandra A. Santos, Arnaud L. J. Desbiez, Humberto L. Perotto-Baldivieso, Juliana M. Alvarez Jan 2020

Evaluating Rangeland's Grazing Capacity For Livestock And Wild Herbivores Using The Delta Diet Tool And Gis Technology, Sandra A. Santos, Arnaud L. J. Desbiez, Humberto L. Perotto-Baldivieso, Juliana M. Alvarez

IGC Proceedings (1977-2023)

Rangelands are dynamic and complex systems requiring appropriate adaptive decision-making to calculate grazing capacity integrating livestock and herbivore wildlife. This work describes the development and application of an integrated framework using the microhistological analysis (DeltaDiet tool) to identify key forage used by different herbivores from the same area associated with GIS technology to mapping landscape containing forage productivity and quality information. This study was conducted in a management unit, representative of the Nhecolândia sub-region landscape, Pantanal. During the dry period, representative fecal samples were collected from cows, capybaras and deer grazing in the same management unit for diet analysis, using …


Glacial Earthquakes And Precursory Seismicity Associated With Thwaites Glacier Calving, J. Paul Winberry, Audrey D. Huerta, Sridhar Anandakrishnan, Richhard C. Aster, Andrew A. Nyblade, Douglas A. Wiens Jan 2020

Glacial Earthquakes And Precursory Seismicity Associated With Thwaites Glacier Calving, J. Paul Winberry, Audrey D. Huerta, Sridhar Anandakrishnan, Richhard C. Aster, Andrew A. Nyblade, Douglas A. Wiens

All Faculty Scholarship for the College of the Sciences

We observe two (~MS 3) long‐period (10–30 s) seismic events that originate from the terminus of Thwaites Glacier, Antarctica. Serendipitous acquisition of satellite images confirm that the seismic events were glacial earthquakes generated during the capsizing of icebergs. The glacial earthquakes were preceded by 6 days of discrete high‐frequency seismic events that can be observed at distances exceeding 250 km. The high‐frequency seismicity displays an increasing rate of occurrence, culminating in several hours of sustained tremor coeval with the long‐period events. A series of satellite images collected during this precursory time period show that the high‐frequency events and …


Glacial Meltwater Modeling To Simulate Lake Water Budget (1996-2013) In Taylor Valley, Antarctica, Julian Michael Cross Jan 2020

Glacial Meltwater Modeling To Simulate Lake Water Budget (1996-2013) In Taylor Valley, Antarctica, Julian Michael Cross

Dissertations and Theses

The McMurdo Dry Valleys (MDV), the largest ice-free region (4,500 km2) in Antarctica, are a polar desert with an average annual temperature of -18ºC. In Taylor Valley, one of the MDV, closed-basin, perennially ice-covered lakes occupy the valley floor. Their water balance is controlled by inflow from glacial meltwater runoff and loss due to sublimation, making them sensitive indicators of climate. In this study, a physically-based model of glacier meltwater and lake ice sublimation is adapted to explain modern (1996 to 2013) lake-level variations. Meltwater model results were improved by the inclusion of MODIS remotely-sensed albedo measurements (E …


Arjen Y. Hoekstra 1967–2019, Davy Vanham, Mesfin Mekonnen, Ashok K. Chapagain Jan 2020

Arjen Y. Hoekstra 1967–2019, Davy Vanham, Mesfin Mekonnen, Ashok K. Chapagain

Daugherty Water for Food Global Institute: Faculty Publications

Arjen Hoekstra introduced the water footprint in 20021, building on the concept of virtual water Tony Allan to discuss the role of trade in alleviating water scarcity in the Middle East. He thereby opened a new dimension in the debate around fair and sustainable allocation of freshwater resources. He laid the foundations to show the role of indirect water (that is, water used elsewhere to produce goods we consume) in our daily life beyond our direct use for drinking, cooking or washing. The water footprint is an indicator of direct and indirect water use by a producer or consumer, showing …


Swine Slurry Characteristics As Affected By Selected Additives And Disinfectants, Jon Duerschner, Shannon L. Bartelt-Hunt, Kent Eskridge, John E. Gilley, Xu Li, Amy M. Schmidt, Daniel D. Snow Jan 2020

Swine Slurry Characteristics As Affected By Selected Additives And Disinfectants, Jon Duerschner, Shannon L. Bartelt-Hunt, Kent Eskridge, John E. Gilley, Xu Li, Amy M. Schmidt, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Current swine industry practice is to house animals in confinement facilities which capture and store feces and urine as slurry in pits below the production area. Additives and disinfectants may be introduced into the manure pits. This study was conducted to measure the effects of additives and disinfectants on temporal changes in swine slurry characteristics. Slurry from a commercial swine production facility in southeast Nebraska, USA was collected and transferred to 57 L reactors located within a greenhouse. Selected additives and disinfectants were added to the reactors and physical properties, chemical characteristics, and antibiotic concentrations were monitored for 40 days. …


Geochemistry And Mineralogy Of The Shallow Subsurface Red Sea Coastal Sediments, Rabigh, Saudi Arabia: Provenance And Paleoenvironmental Implications, Rabea Haredy, Ibrahim Mohamed Ghandour Jan 2020

Geochemistry And Mineralogy Of The Shallow Subsurface Red Sea Coastal Sediments, Rabigh, Saudi Arabia: Provenance And Paleoenvironmental Implications, Rabea Haredy, Ibrahim Mohamed Ghandour

Turkish Journal of Earth Sciences

Mineralogical and geochemical characteristics of the shallow subsurface sediments retrieved from a short sediment core (2.05 m long) collected from the tidal flat south of Al-Kharrar Lagoon, Rabigh area, Saudi Arabia, are presented to determine the impact of temporal change of depositional environment and distinguish the principal control(s) on their chemical composition. The sediments are dominantly siliciclastic, consisting of two vertically stacked sedimentary facies: lagoonal (LG) gray silt-rich mud to argillaceous very fine sand at the base and intertidal flat (TF) brown mud and argillaceous very fine-grained sands at the top. The sediments of the two facies are similar in …


Anthropogenic Hydrometeorological Changes At A Regional Scale: Observed Irrigation-Precipitation Feedback (1979-2015) In Nebraska, Usa, Jozsef Szilagyi, Trenton Franz Jan 2020

Anthropogenic Hydrometeorological Changes At A Regional Scale: Observed Irrigation-Precipitation Feedback (1979-2015) In Nebraska, Usa, Jozsef Szilagyi, Trenton Franz

School of Natural Resources: Faculty Publications

Long-term tendencies in annual, seasonal, and monthly (March) precipitation, evapotranspiration, and air- and dew-point temperature values were correlated with county-level changes in irrigated area across Nebraska over the 1979–2015 period. A statistically significant linear relationship (slope of − 1.65 ± 0.33 mm/decade per % decadal change in irrigated area, with a correlation coefficient of − 0.47) was found between the trends in annual precipitation and irrigated land area. Precipitation dropped by 1 mm annually if the level in irrigation expansion reached about 8% per decade, while the rest of the state enjoyed about a half-millimeter overall increase in annual precipitation …


Chronology Of Advance And Recession Dynamics Of The Southern Green Bay Lobe Of The Laurentide Ice Sheet, South-Central Wisconsin, Usa, Eric C. Carson, John W. Attig, J. Elmo Rawling Iii, Paul R. Hanson, Stefanie E. Dodge Jan 2020

Chronology Of Advance And Recession Dynamics Of The Southern Green Bay Lobe Of The Laurentide Ice Sheet, South-Central Wisconsin, Usa, Eric C. Carson, John W. Attig, J. Elmo Rawling Iii, Paul R. Hanson, Stefanie E. Dodge

School of Natural Resources: Faculty Publications

We used a combination of accelerator mass spectrometry (AMS) radiocarbon dating, optically stimulated luminescence (OSL) age estimates, and stratigraphic data from cores collected along the southern margin of the Green Bay Lobe (GBL) of the Laurentide Ice Sheet to provide new information on the timing and dynamics of the end of advance of the GBL and the dynamics of the ice sheet while very near its maximum position. Coring at multiple sites along the margin of the GBL indicate that ice had reached a stable position near its maximum extent by 24.7 ka; that ice advanced several kilometers to the …


Feeding Behavior Fundamentally Affects Micro-Particle Intake In Mangrove Crabs, Rola Alsharif Jan 2020

Feeding Behavior Fundamentally Affects Micro-Particle Intake In Mangrove Crabs, Rola Alsharif

Scientific Communication News

No abstract provided.


Human Vs. Bear: Who Needs Salmon More?, Brittany N. Savercool Jan 2020

Human Vs. Bear: Who Needs Salmon More?, Brittany N. Savercool

Scientific Communication News

No abstract provided.


How Corals Avoid Mating Between Different Species, Amanda Kempton Jan 2020

How Corals Avoid Mating Between Different Species, Amanda Kempton

Scientific Communication News

No abstract provided.


Microplastics Invade Manta Ray Feeding Grounds Giving Rise To The Effects Of Global Plastic Pollution, Meghan Ulmer Jan 2020

Microplastics Invade Manta Ray Feeding Grounds Giving Rise To The Effects Of Global Plastic Pollution, Meghan Ulmer

Scientific Communication News

No abstract provided.


Battle For The Top: Killer Whales Vs. White Sharks, Michael P. Mcdonough Jan 2020

Battle For The Top: Killer Whales Vs. White Sharks, Michael P. Mcdonough

Scientific Communication News

No abstract provided.


Can Ocean Modeling Help Predict Where Cold-Stunned Sea Turtles Wash Up?, Mikayla L. Twiss Jan 2020

Can Ocean Modeling Help Predict Where Cold-Stunned Sea Turtles Wash Up?, Mikayla L. Twiss

Scientific Communication News

No abstract provided.


White Sharks As A Novel Threat To Sea Otter Populations In California, Kimberly S. Schmutz Jan 2020

White Sharks As A Novel Threat To Sea Otter Populations In California, Kimberly S. Schmutz

Scientific Communication News

No abstract provided.


Feeding Ecology Of Invasive Lionfish In Southeast Florida, Ruchao Qian Jan 2020

Feeding Ecology Of Invasive Lionfish In Southeast Florida, Ruchao Qian

Scientific Communication News

No abstract provided.


Endangered Whale Species In A Pristine Environment: Pollutant Concentrations Indicative Of A Problem?, Briana R. Coulter Jan 2020

Endangered Whale Species In A Pristine Environment: Pollutant Concentrations Indicative Of A Problem?, Briana R. Coulter

Scientific Communication News

No abstract provided.


No Evidence Of Fine Scale Thermal Adaption In Green Turtles, Taylor Apter Jan 2020

No Evidence Of Fine Scale Thermal Adaption In Green Turtles, Taylor Apter

Scientific Communication News

No abstract provided.