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Full-Text Articles in Life Sciences

Integrating Herbivore Population Dynamics Into A Global Land Biosphere Model: Plugging Animals Into The Earth System, Shree R. S. Dangal, Hanqin Tian, Chaoqun Lu, Wei Ren, Shufen Pan, Jia Yang, Nicola Di Cosmo, Amy Hessl Dec 2017

Integrating Herbivore Population Dynamics Into A Global Land Biosphere Model: Plugging Animals Into The Earth System, Shree R. S. Dangal, Hanqin Tian, Chaoqun Lu, Wei Ren, Shufen Pan, Jia Yang, Nicola Di Cosmo, Amy Hessl

Plant and Soil Sciences Faculty Publications

Mammalian herbivores are an essential component of grassland and savanna ecosystems, and with feedbacks to the climate system. To date, the response and feedbacks of mammalian herbivores to changes in both abiotic and biotic factors are poorly quantified and not adequately represented in the current global land surface modeling framework. In this study, we coupled herbivore population dynamics in a global land model (the Dynamic Land Ecosystem Model, DLEM 3.0) to simulate populations of horses, cattle, sheep, and goats, and their responses to changes in multiple environmental factors at the site level across different continents during 1980–2010. Simulated results show …


Coping With Drought In Beef Cattle Production: Innovation Through Optimal Warm-Season Forage Systems, Katelynn Elizabeth Zechiel Dec 2017

Coping With Drought In Beef Cattle Production: Innovation Through Optimal Warm-Season Forage Systems, Katelynn Elizabeth Zechiel

Masters Theses

Drought conditions have had detrimental effects on beef cattle production in the southeastern states where forages are the primary source of feed for livestock. Many southeastern states lie within the fescue-belt, where tall fescue is the predominant livestock forage. Tall fescue is a cool-season (CS) grass that thrives in the cooler temperatures of spring and fall, becoming semi-dormant during peak summer temperatures and again in winter. Conversely, warm-season (WS) forage species increase in production during the summer months and exhibit drought tolerant qualities, making them a viable summer forage option to complement tall fescue for beef cattle producers. The primary …


Pituitary Genomic Expression Profiles Of Steers Are Altered By Grazing Of High Vs. Low Endophyte-Infected Tall Fescue Forages, Qing Li, Raquel Hegge, Phillip J. Bridges, James C. Matthews Sep 2017

Pituitary Genomic Expression Profiles Of Steers Are Altered By Grazing Of High Vs. Low Endophyte-Infected Tall Fescue Forages, Qing Li, Raquel Hegge, Phillip J. Bridges, James C. Matthews

Animal and Food Sciences Faculty Publications

Consumption of ergot alkaloid-containing tall fescue grass impairs several metabolic, vascular, growth, and reproductive processes in cattle, collectively producing a clinical condition known as “fescue toxicosis.” Despite the apparent association between pituitary function and these physiological parameters, including depressed serum prolactin; no reports describe the effect of fescue toxicosis on pituitary genomic expression profiles. To identify candidate regulatory mechanisms, we compared the global and selected targeted mRNA expression patterns of pituitaries collected from beef steers that had been randomly assigned to undergo summer-long grazing (89 to 105 d) of a high-toxic endophyte-infected tall fescue pasture (HE; 0.746 μg/g ergot alkaloids; …


Green Sea Turtles (Chelonia Mydas) In Bermuda Exhibit An Ontogenetic Diet Shift Despite Overexploitation Of Resources In Their Developmental Habitat, Claire Margaret Burgett Mar 2017

Green Sea Turtles (Chelonia Mydas) In Bermuda Exhibit An Ontogenetic Diet Shift Despite Overexploitation Of Resources In Their Developmental Habitat, Claire Margaret Burgett

FIU Electronic Theses and Dissertations

Green sea turtles in Bermuda are overgrazing the seagrasses on which later life stages are thought to specialize. I hypothesized that larger green turtles in Bermuda would display individual diet specializations during seagrass scarcity. Stable isotope methods were used to determine the diet composition of green sea turtles from the Bermuda Platform as a function of size class and in turtles captured in successive years. Individual turtles had a wide range of diets, however, the variation in diets was driven by differences among size class rather than within the size classes of larger turtles, indicating that green turtles undergo a …


Feeding A Novel Trace Mineral At Lower Levels To Grazing Stocker Cattle Does Not Impair Performance, C. S. Weibert, W. R. Hollenbeck, S. B. Laudert, J. D. Kubick, Dale Blasi Jan 2017

Feeding A Novel Trace Mineral At Lower Levels To Grazing Stocker Cattle Does Not Impair Performance, C. S. Weibert, W. R. Hollenbeck, S. B. Laudert, J. D. Kubick, Dale Blasi

Kansas Agricultural Experiment Station Research Reports

When grazing stocker cattle on native Flint Hills pasture, optimizing growth rate is important in determining overall profitability. The correct selection of mineral supplements is an important decision that can be used to help promote overall productivity during a grazing season.


Effects Of Supplementation With Corn Or Dried Distillers Grains On Gains Of Heifer Calves Grazing Smooth Bromegrass Pastures, L. W. Lomas, J. L. Moyer Jan 2017

Effects Of Supplementation With Corn Or Dried Distillers Grains On Gains Of Heifer Calves Grazing Smooth Bromegrass Pastures, L. W. Lomas, J. L. Moyer

Kansas Agricultural Experiment Station Research Reports

A total of 90 heifer calves grazing smooth bromegrass pastures were used to compare supplementation with 0.5% of body weight per head daily of corn or dried distillers grains (DDG) in 2014, 2015, and 2016. Daily gains of heifers supplemented with corn or DDG were similar (P>0.05).


Evaluation Of Supplemental Energy Source For Grazing Stocker Cattle, L. W. Lomas, J. K. Farney, J. L. Moyer Jan 2017

Evaluation Of Supplemental Energy Source For Grazing Stocker Cattle, L. W. Lomas, J. K. Farney, J. L. Moyer

Kansas Agricultural Experiment Station Research Reports

A total of 108 steers grazing smooth bromegrass pastures were used to evaluate the effects of supplemental energy source on available forage, grazing gains, subsequent finishing gains, and carcass characteristics in 2014, 2015, and 2016. Supplementation treatments evaluated were: no supplement, a supplement with starch as the primary source of energy, and a supplement with fat as the primary source of energy. Supplements were formulated to provide the same quantity of protein and energy per head daily. Supplementation with the starch-based or fat-based supplement during the grazing phase resulted in higher (P<0.05) grazing gains than feeding no supplement during all three years. In 2014 and 2016, grazing gains of steers supplemented with the starch-based or fat-based supplement were similar (P>0.05). In 2015, steers supplemented with the fat-based …


Effects Of Interseeding Ladino Clover Into Tall Fescue Pastures Of Varying Endophyte Status On Grazing Performance Of Stocker Steers, L. W. Lomas, J. L. Moyer Jan 2017

Effects Of Interseeding Ladino Clover Into Tall Fescue Pastures Of Varying Endophyte Status On Grazing Performance Of Stocker Steers, L. W. Lomas, J. L. Moyer

Kansas Agricultural Experiment Station Research Reports

Sixty-four yearling steers grazing tall fescue pastures were used to evaluate the effects of fescue cultivar and interseeding ladino clover on grazing gains and available forage. Fescue cultivars evaluated were high-endophyte ‘Kentucky 31,’ low-endophyte ‘Kentucky 31,’ ‘HM4,’ and ‘MaxQ.’ Steers that grazed pastures of low-endophyte ‘Kentucky 31,’ ‘HM4,’ or ‘MaxQ’ gained significantly more (P<0.05) and produced more (P<0.05) gain/a than those that grazed high-endophyte ‘Kentucky 31’ pastures. Gains of cattle that grazed low-endophyte ‘Kentucky 31,’ ‘HM4,’ or ‘MaxQ’ were similar (P>0.05). High-endophyte ‘Kentucky 31’ pastures had more (P<0.05) available forage than lowendophyte ‘Kentucky 31,’ ‘HM4,’ or ‘MaxQ’ pastures.


Effects Of Various Grazing Systems On Grazing And Subsequent Finishing Performance, L. W. Lomas, J. L. Moyer Jan 2017

Effects Of Various Grazing Systems On Grazing And Subsequent Finishing Performance, L. W. Lomas, J. L. Moyer

Kansas Agricultural Experiment Station Research Reports

A total of 280 mixed black yearling steers were used to compare grazing and subsequent finishing performance from pastures with ‘MaxQ’ tall fescue, a wheat-bermudagrass double-crop system, or a wheat-crabgrass double-crop system in 2010, 2011, 2012, 2013, 2014, 2015, and 2016. Daily gains of steers that grazed MaxQ fescue, wheatbermudagrass, or wheat-crabgrass were similar (P>0.05) in 2010 and 2016. Daily gains of steers that grazed wheat-bermudagrass or wheat-crabgrass were greater (P>0.05) than those that grazed MaxQ fescue in 2011 and 2012. Daily gains of steers that grazed wheat-crabgrass were greater (P>0.05) than those that grazed wheat-bermudagrass and …