Life Sciences Commons^™

Litter Decomposition And Root Production In Response To Grazing On Sandhills Subirrigated Meadow, Ben W. Beckman

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

Stocking density can be manipulated by management factors including herd size, pasture size, and grazing period length. Ultrahigh stocking density (mob grazing) is commonly characterized at 200,000 kg animal live weight ha^-1 or higher with multiple movements of livestock per day. Practitioners claim increased plant production, soil development, and nutrient cycling rates because of high trampling percentages resulting from ultrahigh socking densities. This study was conducted on subirrigated meadow in the Nebraska Sandhills in 2012 and 2013 to determine grazing method effect on annual root production and litter decomposition. Stocking rates were held constant while stocking densities varied by …

Effects Of Stocking Rate On Forage Nutrient Composition Of Nebraska Sandhills Upland Range When Grazed In Early Summer And The Effects Of Grazing On Nebraska Sandhills Meadow Forage Nutrient Compostion, Jared V. Judy

Department of Animal Science: Dissertations, Theses, and Student Research

The objectives of this research were to 1) evaluate the effects of stocking rate on forage nutrient quality 2) quantify the relative proportions of current vs. previous year growth being consumed in early summer upland range pastures and 3) determine how grazing effects forage nutrient quality in subirrigated meadows in the Nebraska Sandhills. Experiment 1 was a two year study conducted on the experimental upland range paddocks at Gudmundsen Sandhills Laboratory. Twelve 2-hectare paddocks were assigned one of three treatments stocked at 0 (control), 0.57 (light), and 0.85 (heavy) AUM/ha. Ten 0.25 m² quadrats were clipped per paddock during …

Dangerous Mating Systems: Signal Complexity, Signal Content And Neural Capacity In Spiders, Marie E. Herberstein, Anne E. Wignall, Eileen Hebets, Jutta M. Schneider

Eileen Hebets Publications

Spiders are highly efficient predators in possession of exquisite sensory capacities for ambushing prey, combined with machinery for launching rapid and determined attacks. As a consequence, any sexually motivated approach carries a risk of ending up as prey rather than as a mate. Sexual selection has shaped courtship to effectively communicate the presence, identity, motivation and/or quality of potential mates, which help ameliorate these risks. Spiders communicate this information via several sensory channels, including mechanical (e.g. vibrational), visual and/or chemical, with examples of multimodal signaling beginning to emerge in the literature. The diverse environments that spiders inhabit have further shaped …

Effects Of Sorting Prior To Feeding Zilpaterol Hydrochloride And Effects Of Different Implant Strategies On Feedlot Performance And Carcass Characteristics Of Steers And Heifers, Fred H. Hilscher Jr

Department of Animal Science: Dissertations, Theses, and Student Research

Two experiments evaluated the effects of sorting and feeding Zilpaterol hydrochloride (ZH) to steers on feedlot performance and carcass characteristics. In Exp. 1, treatments compared unsorted cattle either fed ZH or not, and three treatments utilizing 1 sort at the beginning, middle or end of the finishing period. In Exp. 2, treatments compared unsorted cattle fed ZH, and two treatments that utilized 1 sort based on initial BW or 4 sorts at the end of the finishing period. Feeding ZH increased BW, HCW and percentage of overweight carcasses; however, sorting decreased carcass weight standard deviations, and percent overweight carcasses. Feeding …

Production Of Recombinant Human Coagulation Factor Ix By Transgenic Pig, Weijie Xu

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Hemophilia B is the congenital bleeding disorder caused by deficiency in functional coagulation factor IX (FIX) and about 28,000 patients worldwide in 2012. And current treatment is restricted to protein-replacement therapy, which required FIX concentrates for patients’ life-time. Approximately 1 billion units FIX were consumed in 2012. However, still about 70-80% patients, mostly in developing countries, received inadequate or no treatment because of the unavailable and/or unaffordable FIX concentrates. Considering safety reasons, e.g. transmission of blood-borne diseases, the recombinant human FIX (rFIX) is recommended other than the plasma-derived FIX. However, only one rFIX is currently available on the market. The …

Stop Lion Hunting, Paul A. Johnsgard

Paul Johnsgard Collection

According to my informal tally, at least seven mountain lions have so far been killed in Nebraska during 2014, as follows: 1 & 2: Two were killed on January 1 and 2, at the start of Nebraska's first hunting season. Both were killed by treeing the animals with dogs, then shooting them execution style. One was killed by a man who bought the permit ($13,500) at auction; the other by a teenager who won a Game & Park's fund -raising lottery. 3: An adult male was accidentally killed by a vehicle on February 1, in Sioux County. 4: An adult …

New Species Records And Changes In Abundance Of Waterfowl In Northwest Greenland, K. K. Burnham, D. R. Sinnett, J. A. Johnson, J. L. Burnham, J. A. Baroch

United States Department of Agriculture Wildlife Services: Staff Publications

Breeding populations of Nearctic and Palearctic waterfowl have undergone significant changes in abundance and distribution over the past 50 years. The Avanersuaq District in northwest Greenland is home to an assemblage of waterfowl from both geographic areas; however, minimal historic or current information is available on species abundance. In 2008 and 2009, we conducted field surveys in Greenland from 76.00_ to 77.35_N for breeding and non-breeding waterfowl and have collected anecdotal field notes of avian observations over a 20-year period (1993–2012). During these periods, we documented the first observation of a Ross’s goose (Chen rossii) and the first confirmed breeding …

Harvest Incentives: A Tool For Managing Aquatic Invasive Species, Bob Wiltshire, Nathan Stone, Marshall Meyers, Bill Hyatt, Lori Williams, Jason Goldberg, Susan Pasko, Leah Elwell

National Invasive Species Council

Conclusion

The success of any harvest incentive program to address aquatic invasive species will depend upon numerous biological, socioeconomic, and legal considerations. Programs that encourage harvest may be a successful management tool in targeting small, distinct populations; in high priority areas within a larger invasion; or they may play a supplementary role within larger control programs. Their use, however, will require careful review, planning, and monitoring to ensure success and that they do not unintentionally lead to further spread of invasive species, cause additional harm to native species, or waste valuable resources.

A Male Spider’S Ornamentation Polymorphism Maintained By Opposing Selection With Two Niches, Bo Deng, Alex Estes, Brett Grieb, Douglas Richard, Brittney Hinds, Eileen Hebets

Eileen Hebets Publications

The Levene mechanism to maintain genotypic polymorphism by opposing selection on genotypes in multiple niches was proposed 60 years ago, and yet no systems were found to satisfy the mechanisms rather restrictive conditions. Reported here is such an example that a wolf spider population lives in a habitat of mixed rocks and leafy litter for which the females are phenotypically indistinguishable and the males have two distinct phenotypes subject to opposing selection with respect to the substrates. Census data is best-fitted to a population genetics model of the Levene type. A majority of the best fit support polymorphism, with many …

Effects Of Conventional And Alternative Curing Methods On Processed Turkey Quality Traits, Amy Lynn Redfield

Department of Animal Science: Dissertations, Theses, and Student Research

This study compared physicochemical and sensory qualities of deli-style turkey breast produced pre-converted celery juice powder (CP; for alternative curing) or sodium nitrite (SN; for conventional curing). Formulas were designed to include 0, 50, 100, 150, and 200 ppm ingoing sodium nitrite or the equivalent from CP or SN, and 3 replicates of products were manufactured. Turkey and curing brines were tumbled, stuffed, and cooked to an internal temperature of 73.9^oC. Products were stabilized and sliced into 12 mm slices (physicochemical trait analysis) and 2 mm slices (sensory trait analysis). Physicochemical traits measured only on d 0 were …

Genome-Wide Analysis Of The Variation In Host Genetics In Response To Experimental Challenges With Porcine Circovirus 2b, Taylor B. Engle

Department of Animal Science: Dissertations, Theses, and Student Research

Porcine circovirus is the primary causative agent responsible for inducing a group of associated diseases known as porcine circovirus associated diseases (PCVAD), which can have detrimental effects on production efficiency as well as lead to mortality. The variation in host genetics plays a role in the ability to initiate an effective immune response. The objective of this research was to identify major genetic variants and genes that influence immune response and PCVAD susceptibility. Commercial crossbred pigs (n=974) were experimentally infected with a PCV2b strain to analyze genetic sources of variation in PCVAD susceptibility. The strain used for experimental infection was …

The Role Of Sirtuin 1 And Ceramide In T10C12 Conjugated Linoleic Acid Induced Delipidation In 3t3-L1 Adipocytes, Wei Wang

Department of Animal Science: Dissertations, Theses, and Student Research

Project 1: Trans-10, cis-12 conjugated linoleic acid (t10c12 CLA) reduces triglyceride (TG) levels in adipocytes through multiple pathways, with AMP-activated protein kinase (AMPK) generally facilitating, and peroxisome proliferator-activated receptor γ (PPARγ) generally opposing these reductions. Sirtuin 1 (SIRT1), a histone/protein deacetylase that affects energy homeostasis, often functions coordinately with AMPK, and is capable of binding to PPARγ, thereby inhibiting its activity. This study investigated the role of SIRT1 in the response of 3T3-L1 adipocytes to t10c12 CLA by testing the following hypotheses: 1) SIRT1 is functionally required for robust TG reduction; …

Hymenolepis Robertrauschi N. Sp. From Grasshopper Mice Onychomys Spp. In New Mexico And Nebraska, U.S.A., Scott Lyell Gardner, Brent A. Luedders, Donald W. Duszynski

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

From 1989 through 1998, a total of 358 grasshopper mice were collected and examined for helminth and protistan parasites from several habitat types on the Sevilleta Long Term Ecological Research (LTER) site in New Mexico, U.S.A. Of these, 205 individuals were identified as Onychomys leucogaster (Wied-Neuwied 1841) and 153 individuals were classified as O. arenicola Mearns 1896. Many individuals of Onychomys were infected with a new species of Hymenolepididae (Hymenolepis robertrauschi), which is herein described, illustrated, and compared with all species of Nearctic Hymenolepis s. str. Hymenolepis robertrauschi was found in 26% of the individuals of O. arenicola …

Microsporidia Biological Control Agents And Pathogens Of Beneficial Insects, Susan Bjornson, David Oi

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

No abstract provided.

An Illustrated Id Guide To The Crayfishes Found In Nebraska Native And Non-Native, Steve Schainost

Nebraska Invasive Species Program

There are five crayfishes native to Nebraska. These are:

Orconectes immunis (papershell crayfish)

Orconectes virilis (northern crayfish)

Orconectes neglectus neglectus (ringed crayfish)

Cambarus diogenes (Devil crayfish)

Procambarus gracilis (prairie crayfish)

Three additional non-native crayfishes have also been found here:

Orconectes rusticus (rusty crayfish) [bait tanks and established in two ponds in Omaha]

Procambarus clarkii (red swamp crayfish) [bait tanks]

Procambarus acutus (White River crayfish) [bait tanks]

I will attempt here to provide a photographic guide to field identification, one species per page.