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Full-Text Articles in Agriculture

Litter Decomposition And Root Production In Response To Grazing On Sandhills Subirrigated Meadow, Ben W. Beckman Dec 2014

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 Dec 2014

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 …


Energy Value Of De-Oiled Distillers Grains Plus Solubles In Beef Cattle Diets, Meredith L. Bremer Dec 2014

Energy Value Of De-Oiled Distillers Grains Plus Solubles In Beef Cattle Diets, Meredith L. Bremer

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

Ethanol plants are centrifuging off oil from the thin stillage stream as it has added market value currently. The impact of oil removal on cattle performance has been minimally researched. Thus four trials, one growing, one digestion, and two feedlot, were designed to determine the energy and feeding value of de-oiled distillers grains in beef cattle diets.

In growing cattle diets, diet concentration of modified distillers grains plus solubles (MDGS) impacted cattle performance more than oil content. Ending BW, ADG, and G:F did not differ between cattle fed de-oiled or full fat MDGS, however cattle fed de-oiled MDGS had lower …


Performance Of A Temperate-Zone Channel Catfish Biofloc Technology Production System During Winter, Bartholomew W. Green Nov 2014

Performance Of A Temperate-Zone Channel Catfish Biofloc Technology Production System During Winter, Bartholomew W. Green

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

Channel catfish (Ictalurus punctatus) have been grown successfully in an outdoor biofloc technology production system. Outdoor biofloc production systems in the tropic sare operated year-round, whereas the channel catfish studies were conducted only during the growing season and biofloc production tanks were harvested and idled for the winter. If an outdoor biofloc production system is to be adopted by farmers at temperate latitudes, then data gaps related to system and fish performance over the winter must be addressed. The present study was conducted to address these data gaps for channel catfish culture. Waters from a recently completed biofloc …


2014 Nebraska Beef Cattle Report Sep 2014

2014 Nebraska Beef Cattle Report

Nebraska Beef Cattle Reports

Contents:

Cow/Calf

Effect of Pubertal Status and Number of Estrous Cycles Prior to the Breeding Season on Pregnancy Rate in Beef Heifers .5

Comparison of Long-term Progestin-based Synchronization Protocols on Fixed-time AI pregnancy Rate in Beef Heifers . 8

Androgen Excess in Beef Cows Results in Altered Theca Cell Gene Expression and Fertility 11

Follicular Vascular Endothelial Growth Factor A Expression Before and After the LH Surge . 14

Evaluation of Genomic Predictors for Red Angus Cattle . 17

Preconception Distillers Grains Supplementation Improves Mature Beef Cow Return to Estrous . 19

Impact of Supplemental Protein Source on Pregnant Heifers …


Patch-Burn Grazing Effects On Cattle Performance: Research Conducted In A Working Landscape, Stephen L. Winter, Samuel D. Fuhlendorf, Mark Goes Jun 2014

Patch-Burn Grazing Effects On Cattle Performance: Research Conducted In A Working Landscape, Stephen L. Winter, Samuel D. Fuhlendorf, Mark Goes

School of Natural Resources: Faculty Publications

• Patch-burn grazing is a range management strategy that might be able to simultaneously optimize livestock production objectives and wildlife habitat objectives.

• We compared patch-burn grazing to a traditional range management strategy in multiple pastures, representing a variety of land ownership and management histories, dispersed across a relatively large geographic area. Our results likely represent what land managers could expect if they adopted patch-burn grazing in similar situations.

• We found that cattle performance in pastures managed with patch-burn grazing did not differ from that found in pastures managed with a traditional range management strategy. This suggests that land …


Genome-Wide Analysis Of The Variation In Host Genetics In Response To Experimental Challenges With Porcine Circovirus 2b, Taylor B. Engle May 2014

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 …


Nebraska Bqa: Antibiotic Use Guidelines, Rob Eirich Jan 2014

Nebraska Bqa: Antibiotic Use Guidelines, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattlemen have demonstrated a commitment to animal health through vaccination programs developed carefully in cooperation with their veterinarian. When animals must be treated with an antibiotic after disease diagnosis, producers need to follow important antibiotic use guidelines established through the National Beef Quality Assurance (BQA) program.


Nebraska Bqa: Effective Cattle Handling, Rob Eirich Jan 2014

Nebraska Bqa: Effective Cattle Handling, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattlemen know the importance of proper cattle handling and its effect on animal health and performance. Beef Quality Assurance has been implementing effective cattle handling (low-stress) into educational programs since its establishment in the 1980s.


Handling Cattle Through High Heat Humidity Indexes, Rob Eirich Jan 2014

Handling Cattle Through High Heat Humidity Indexes, Rob Eirich

Nebraska Beef Quality Assurance Program

As cattlemen enter the summer months, they need to understand and deal with heat and humidity. Consider incorporating the following practices into management plans to help reduce additional stress.


Nebraska Bqa: Handling Compromised Animals, Rob Eirich Jan 2014

Nebraska Bqa: Handling Compromised Animals, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattle producers have long recognized the need of proper husbandry and stewardship for the animals entrusted into their care. Best livestock production practices, based on research and sound science, help ensure the well-being, animal health and productivity of cattle.


Calf Branding/Processing Time And Beef Quality Assurance, Rob Eirich Jan 2014

Calf Branding/Processing Time And Beef Quality Assurance, Rob Eirich

Nebraska Beef Quality Assurance Program

It is spring and that means branding time across cattle country. As producers are finishing calving season and preparing for branding/processing, it is important to review Beef Quality Assurance (BQA) guidelines. Let's take a minute to look at the key BQA principles:


Audits And Assessments In Beef Cattle Production, Rob Eirich Jan 2014

Audits And Assessments In Beef Cattle Production, Rob Eirich

Nebraska Beef Quality Assurance Program

Assessments and audits are becoming a part of doing business in beef cattle production, as we are seeing beef processors implementing third-party audits. Since beginning as the Nebraska Director of Beef Quality Assurance (BQA) in July, I have been studying and gathering information on the National Cattlemen's Beef Association (NCBA) Assessment Guides and third-party audits in the beef industry.


Nebraska Beef Quality Assurance: Focused On The Safety, Wholesomeness And Quality Of Beef Jan 2014

Nebraska Beef Quality Assurance: Focused On The Safety, Wholesomeness And Quality Of Beef

Nebraska Beef Quality Assurance Program

Across the nation, beef producers face the challenge of making a living from the land, while producing safe, wholesome beef. Beef that will provide a great eating experience each and every time for American and International consumers.


Effect Of Stocking Biomass On Solids, Phytoplankton Communities, Common Off-Flavors, And Production Parameters In A Channel Catfish Biofloc Technology Production System, Bartholomew W. Green, Kevin K. Schrader, Peter W. Perschbacher Jan 2014

Effect Of Stocking Biomass On Solids, Phytoplankton Communities, Common Off-Flavors, And Production Parameters In A Channel Catfish Biofloc Technology Production System, Bartholomew W. Green, Kevin K. Schrader, Peter W. Perschbacher

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

The effect of initial channel catfish (Ictalurus punctatus, Rafinesque, 1818) fingerling biomass (1.4, 1.8, or 2.3 kg m-3) on phytoplankton communities, common off-flavours and stocker catfish production parameters was evaluated in biofloc technology production tanks. Stocker catfish size (145.5–172.6 g fish-1) at harvest did not differ among treatments, but net yield increased linearly as initial biomass increased (R2 = 0.633). Mean total feed consumption increased linearly with initial catfish biomass (R2 = 0.656) and ranged from 10.7 to 15.8 kg m -3. Total suspended solids (TSS) in all treatments increased linearly …


Fate Of Antimicrobials And Antimicrobial Resistance Genes In Simulated Swine Manure Storage, Stacey R. Joy, Xu Li, Daniel D. Snow, John Gilley, Bryan L. Woodbury, Shannon L. Bartelt-Hunt Jan 2014

Fate Of Antimicrobials And Antimicrobial Resistance Genes In Simulated Swine Manure Storage, Stacey R. Joy, Xu Li, Daniel D. Snow, John Gilley, Bryan L. Woodbury, Shannon L. Bartelt-Hunt

School of Natural Resources: Faculty Publications

The behavior of three antibiotics (bacitracin, chlortetracycline, and tylosin) and two classes of antibiotic resistance genes (ARGs), tet and erm, were monitored in swine manure slurry under anaerobic conditions. First-order decay rates were determined for each antibiotic with half-lives ranging from1 day (chlortetracycline) to 10 days (tylosin). ARGs were monitored in the swine manure slurry, and losses of approximately 1 to 3 orders of magnitude in relative abundance were observed during the 40 day storage period. First-order degradation profiles were observed for chlortetracycline and its corresponding resistance genes, tet(X) and tet(Q). Tylosin was degraded to approximately 10% …