Life Sciences Commons^™

Pasture Chemoscapes And Their Ecological Services, Juan J. Villalba, Karen A. Beauchemin, Pablo Gregorini, Jennifer W. Macadam

Wildland Resources Faculty Publications

Ruminant livestock-production systems are between a rock and a hard place; they are experiencing increasing societal pressure to reduce environmental impacts in a world that demands increased food supply. Recent improvements in the understanding of the nutritional ecology of livestock by scientists may help livestock producers respond to these seemingly contradictory demands. Forages are nutrition and pharmacy centers with primary (nutrients) and plant secondary compounds (PSC; pharmaceuticals, nutraceuticals), which can provide multiple services for the proper functioning of agroecosystems. Legumes with lower contents of fiber and higher contents of nonstructural carbohydrates, coupled with different types and concentrations of PSC (e.g., …

Evaluation Of Protein Utilization In Low And High Protein Forage Sources And The Economic Value Of Supplementing Field Peas (Pisum Sativum) To Growing Cattle Grazing Crested Wheatgrass Pastures, Braden C. Troyer

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

Field peas are widely grown in the panhandle of Nebraska; however, markets quickly become saturated. A two year experiment was conducted comparing field peas to dry distillers grains with solubles (DDGS) as a protein supplement. The objective was to establish a price producers could pay for field peas relative to DDGS. There was a significant difference in ADG due to type of supplement (P = 0.02). Field pea supplemented heifers had 10% lower ADG compared to DDGS supplemented heifers. Economically, this means if DDGS is priced at or $124.58/ 909 kg DM a producer could pay $2.89/ 27 kg, …

Medication Darts Are Gaining In Popularity - Do They Affect Meat Quality? Are There Risks?, David J. Wilson, Kerry A. Rood

All Current Publications

Livestock, such as beef cattle or post-weaned dairy cattle that are not yet milking, are often relatively “tame” (sometimes the term tame may not apply very well) and can be readily approached within a few feet. However, without adequate restraint facilities or enough personnel, actually treating the livestock is often difficult and can become frustrating and dangerous to people and animals. A solution to this problem, which is being rapidly and increasingly adopted, is the use of medication darts. Nevertheless, many in the cattle industry are raising some concerns. What are some of the characteristics of medication darts? Is there …

Evaluation Of The Effects Of Biochar On Diet Digestibility And Methane Production From Growing And Finishing Steers, Thomas Winders, Melissa L. Jolly, Hannah C. Wilson, James C. Macdonald, Galen E. Erickson, Andrea K. Watson

Department of Animal Science: Faculty Publications

The objectives of these studies were to evaluate the effects of biochar (0%, 0.8%, or 3% of diet dry matter) on diet digestibility and methane and carbon dioxide production from cattle on growing and finishing diets. The growing diet consisted of 21% brome hay, 20% wheat straw, 30% corn silage, 22% wet distillers grains plus solubles, and 7% supplement. The finishing diet consisted of 53% dry-rolled corn, 15% corn silage, 25% wet distillers grains plus solubles, and 7% supplement. In both trials biochar replaced fine ground corn in the supplement. Six crossbred steers (initial body weight [BW] 529 kg; SD …

Attainment And Maintenance Of Pubertal Cyclicity May Predict High A4 Cows With Reduced Fertility, Sarah Nafziger

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

Puberty attainment was investigated in heifers. Blood samples were collected from weaning until breeding during 6 years from heifers born in 2012-2017. Plasma progesterone concentrations ≥ 1 ng/ml were used to indicate cyclicity, and heifers were categorized into one of four puberty groups using SAS: 1) Early heifers reached puberty before March 12 and cycled continuously during the sampling period, 2) Typical heifers reached puberty on or after March 12 and cycled continuously, 3) Start-Stop heifers had at least one occurrence of progesterone ≥ 1 ng/ml but discontinued cycling during the sampling period, and 4) Non-Cycling heifers had no occurrence …

Comparison Of Different Functions To Describe Growth From Weaning To Maturity In Crossbred Beef Cattle, Madeline J. Zimmermann, Larry A. Kuehn, Matthew L. Spangler, R. Mark Thallman, Warren M. Snelling, Ronald M. Lewis

Department of Animal Science: Faculty Publications

Cow mature weight (MWT) has increased in the past 30 yr. Larger cows cost more to maintain, but their efficiency—and thus profitability— depends on the production environment. Incorporating MWT effectively into selection and mating decisions requires understanding of growth to maturity. The objective of this study was to describe growth to maturity in crossbred beef cattle using Brody, spline, and quadratic functions. Parameter estimates utilized data on crossbred cows from cycle VII and continuous sampling phases of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. The MWT were estimated at 6 yr from the fitted parameters obtained …

Identifying Breed Effects For Cow Mature Weight, Madeline J. Zimmermann

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

Mature weight (MWT) in beef cattle has increased over the past 30 yr. In general, larger cows are costlier to maintain than smaller cows, and their profitability depends on their production environment. A wide range of beef production environments exist in the United States. There are also a variety of beef cattle breeds that can be chosen and mated to create a type of cow which will be optimally suited to excel in a given environment. However, there remains a need for tools allowing effective comparison among breeds to facilitate such decision making. Unfortunately, estimated progeny differences ( …

Environmental And Animal Benefits When Beef Cattle Consume Condensed And Hydrolysable Tannins, Elizabeth K. Stewart, Juan J. Villalba, Kerry A. Rood

All Current Publications

This fact sheet describes the environmental and animal benefits when cattle consume condensed and hydrolysable tannins, and includes producer concerns.

Evaluation Of Alpha Amylase Containing Corn On Finishing Cattle Performance And Digestibilty, Melissa L. Jolly-Breithaupt

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

One digestion and four finishing trials were conducted to evaluate the effect of a new corn hybrid containing an α-amylase trait, Syngenta Enogen Feed Corn (SYT-EFC) on site and extent of digestion, ruminal fermentation parameters, and feedlot performance. Experiments utilized corn containing the enzymatic gene compared to controls, the near isoline parental corn (NEG) or commercially available corn grain (CON), processed as dry-rolled corn (DRC) or high moisture corn (HMC) in diets with dry [distillers grains plus solubles (DGS)] or wet (Sweet Bran) milling byproducts. The corn grain of the experimental diets were fed as the sole grain source, comprising …

Construction Of A Pen-Scale Methane Collection System And Dietary Strategies For Methane Mitigation From Growing And Finishing Cattle, Thomas Winders

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

Methane production from ruminants has been researched for many years because it has a global warming potential 25x that of carbon dioxide, meaning that mitigating smaller amounts of methane can have a large environmental impact. Research has focused on individual animal methane measurements, but the literature lack in industry-scale measurements. For that reason, the methane barn was built to evaluate dietary strategies on pens of cattle rather than on individual animals. In order to test the methane barn capabilities, an experiment designed to produce differences in methane production was conducted. Cattle received the same growing diet, at either ad-libitum access …

Supplementation And Reproductive Strategies For Beef Females As Part Of A May-Calving Herd In The Nebraska Sandhills, Alicia Caitlin Lansford

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

The objective of these 4 studies was to evaluate the effects of management decisions on reproductive performance of beef females. Experiment 1 evaluated the efficacy of a novel s.c. prostaglandin F_2a injection on estrus synchronization and pregnancy success in yearling beef heifers. Heifers receiving a 2 mL s.c. injection of Lutalyse HighCon had similar estrus response and pregnancy rates compared to 5 mL Lutalyse i.m. within 2 different estrus synchronization programs. In experiment 2, May-calving heifers and primiparous cows were allotted to receive either no supplementation or supplement (0.45 or 0.91 kg/d per animal, heifers or primiparous cows, …

Genome-Wide Association Study For The Relationship Between Temperature And Feed Intake In Beef Cattle, Robel Ghebrewold

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

The interaction of livestock with the environment they live in is complex and plays a significant role in their production performance, which also depends on location and management practices. Climate change is projected to increase temperature globally. As a result, climate change will most likely aggravate the pressure from different sources of stressors on the current agricultural production system in general and in livestock specifically. Environmental conditions, such as changes in ambient temperature, can cause changes in animal behavior and performance. In general, it is believed that as ambient temperature increases, dry matter intake (DMI) of beef cattle decreases. However, …

Risks Associated To Different Methods Of Increasing Pregnancy Rate Of Cows In Cow-Calf Systems, Tamara Esteves De Oliveira, Julio Otavio Jardim Barcellos, Jack Whittier, Odilene De Souza Teixeira, David Santos De Freitas, Ricardo Pedroso Oaigen, Matheus Dhein Dill, Concepta Mcmanus

Department of Animal Science: Faculty Publications

This study assessed the risks of different management practices to increase pregnancy rate in beef cow-calf systems, aiming at assisting decision-making. The perception of 18 experts on animal sciences regarding the risks of 32 nutritional, breeding, and general management practices applied to increase pregnancy rate were evaluated through questionnaires. The experts were selected by a non-probability sampling of researchers on veterinary and animal sciences. In addition, five farmers and eight technical consultants were also selected. The questionnaire was applied during a face-to-face meeting. The risk of each practice was assessed according to four factors, namely, cost, technical knowledge, operational complexity, …

Effects Of Syngenta Enogen Feed Corn Containing An Α-Amylase Trait On Finishing Cattle Performance And Carcass Characteristics, M. L. Jolly-Breithaupt, M. E. Harris, B. L. Nuttelman, D. B. Burken, J. C. Macdonald, M. K. Leubbe, T. K. Iragavarapu, G. E. Erickson

Department of Animal Science: Faculty Publications

Two experiments evaluated the effects of feeding a new corn hybrid, containing an α-amylase enzyme trait, Syngenta Enogen Feed Corn (SYT-EFC), on feedlot performance and carcass characteristics at two locations. Experiment 1 utilized 300 calffed steers (298.5 ± 16.3 kg of BW) at the University of Nebraska–Lincoln Eastern Nebraska Research and Extension Center Mead, NE. Treatments were designed as a 2 × 2 + 1– factorial arrangement with factors consisting of 1) corn type (SYT-EFC or conventional [CON]) and 2) byproduct type (with or without Sweet Bran [SB]), or a BLEND of STY-EFC and CON without SB. In Exp. 2, …

Elucidation Of The Molecular Mechanism Through Which Estradiol And Trenbolone Acetate Improve Skeletal Muscle Growth In Beef Cattle, Kara Thornton-Kurth

Funded Research Records

No abstract provided.

Rumen Bacterial Community Structure Impacts Feed Efficiency In Beef Cattle, Henry A. Paz, Kristin E. Hales, James E. Wells, Larry A. Kuehn, Harvey C. Freetly, Elaine D. Berry, Michael D. Flythe, Matthew L. Spangler, Samodha C. Fernando

Department of Animal Science: Faculty Publications

The importance of the rumen microbiota on nutrient cycling to the animal is well recognized; however, our understanding of the influence of the rumen microbiome composition on feed efficiency is limited. The rumen microbiomes of two large animal cohorts (125 heifers and 122 steers) were characterized to identify specific bacterial members (operational taxonomic units [OTUs]) associated with feed efficiency traits (ADFI, ADG, and G:F) in beef cattle. The heifer and steer cohorts were fed a forage-based diet and a concentrate-based diet, respectively. A rumen sample was obtained from each animal via esophageal tubing and bacterial community composition was …

Understanding The Contributions Of Beef Cattle To Greenhouse Gas Emissions, Elizabeth Stewart, Eric Thacker, Matthew D. Garcia, Juan J. Villalba

All Current Publications

This fact sheet describes current and projected beef consumption, methane, nitrogen, beef cattle production, and possibilities for more sustainable beef production.

Collection Of Biological Material For Commercial Genomic Testing In Beef, Matthew D. Garcia, Kevin Heaton, Linden Greenhalgh

All Current Publications

This fact sheet describes collecting biological material for commercial genomic testing of beef cattle. It includes a description of materials needed, methods of collecting including blood, ear notching, or tissue collection, and how to ship and store samples.

Economic Selection Index Development For Beefmaster Cattle I: Terminal Breeding Objective, Kathleen P. Ochsner, M. D. Macneil, Matthew L. Spangler

Department of Animal Science: Faculty Publications

The objective of this study was to develop an economic selection index for Beefmaster cattle in a terminal production system where bulls are mated to mature cows with all resulting progeny harvested. National average prices from 2010 to 2014 were used to establish income and expenses for the system. Phenotypic and genetic parameter values among the selection criteria and goal traits were obtained from literature. Economic values were estimated by simulating 100,000 animals and approximating the partial derivatives of the profit function by perturbing traits one at a time, by 1 unit, while holding the other traits constant at their …

Economic Selection Index Development For Beefmaster Cattle Ii: General-Purpose Breeding Objective, Kathleen P. Ochsner, M. D. Macneil, Ronald M. Lewis, Matthew L. Spangler

Department of Animal Science: Faculty Publications

An economic selection index was developed for Beefmaster cattle in a general-purpose production system in which bulls are mated to a combination of heifers and mature cows, with resulting progeny retained as replacements or sold at weaning. National average prices from 2010 to 2014 were used to establish income and expenses for the system. Genetic parameters were obtained from the literature. Economic values were estimated by simulating 100,000 animals and approximating the partial derivatives of the profit function by perturbing traits 1 at a time, by 1 unit, while holding the other traits constant at their respective means. Relative economic …

The Impact Of Training Strategies On The Accuracy Of Genomic Predictors In United States Red Angus Cattle, J. Lee, Stephen D. Kachman, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Genomic selection (GS) has become an integral part of genetic evaluation methodology and has been applied to all major livestock species, including beef and dairy cattle, pigs, and chickens. Significant contributions in increased accuracy of selection decisions have been clearly illustrated in dairy cattle after practical application of GS. In the majority of U.S. beef cattle breeds, similar efforts have also been made to increase the accuracy of genetic merit estimates through the inclusion of genomic information into routine genetic evaluations using a variety of methods. However, prediction accuracies can vary relative to panel density, the number of folds used …

Weaning Strategies In Beef Cattle To Reduce Stress, Matthew Garcia, Kerry Rood, Clark Israelsen

All Current Publications

This fact sheet considers weaning strategies for beef cattle, including the advantages and disadvantages of fenceline weaning, and twostep weaning.

Understanding The Semen Evaluation Portion Of The Breeding Soundness Evaluation, C. Kim Chapman, Kerry A. Rood

All Current Publications

This fact sheet explains the semen examination section of the bull breeding soundness evaluation form. It indicates what each category on the form is, why it is important, and what the requirements are for a bull to be considered a satisfactory breeder.

Development Of Terminal And Maternal Economic Selection Indices In Beefmaster Cattle, Kathleen P. Ochsner

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

In the design of economic selection indices, the relative importance of traits in the breeding objective is reflected by their relative economic weighting. The objective of this study was to develop two economic selection indices for Beefmaster cattle: one for a terminal production system and one for a maternal production system. The terminal index was developed assuming bulls are mated to mature cows with all resulting progeny harvested. The maternal index was developed assuming bulls are mated to a combination of heifers and mature cows, with resulting progeny retained as replacements or sold at weaning.

National average prices from 2010 …

Genetic Parameters For Docility, Weaning Weight, Yearling Weight And Intramuscular Fat Percentage In Hereford Cattle, Jose A. Torres-Vazquez

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

Temperament in cattle can be described as the reactivity or fear response to human handling, and it is important to beef cattle producers not only from a human safety but also due to potential correlations with other economically traits. Before a docility selection metric can be added to a genetic evaluation, any potential antagonisms with economically relevant traits should be quantified. The objective was to estimate genetic parameters, including genetic correlations, for chute score (CS), weaning weight (WW), yearling weight (YW), and intramuscular fat percentage (IMF) in Hereford cattle. Single-trait and bivariate animal models were used to estimate heritabilities and …

Effect Of Grazing Prairie Dog—Colonized Rangeland On Cattle Nutrition And Performance: A Progress Report, Kenneth C. Olson, Christopher Schauer, Chanda Engel, Janna J. Kincheloe, Jameson R. Brennan, Ben L. Hauptman

Natural Resource Management Faculty Publications

On the Ground

• One objective of the ongoing Renewal on Standing Rock Reservation project is to evaluate the response of grazing steers to the level of prairie dog colonization on Northern Mixed Grass Prairie.
• We fenced four pastures to create an increasing gradient of a proportion of the pasture area colonized by prairie dogs. Pastures are stocked with yearling steers during each growing season.
• Comparing steer performance, Global Positioning System (GPS) locations of grazing, diet samples, and ingestive behavior at each proportion of the prairie dog colony per pasture allows prediction of the optimal proportion of colonization, which enables selection …

Feeding Wet Distillers Grains Plus Solubles With And Without A Direct-Fed Microbial To Determine Performance, Carcass Characteristics, And Fecal Shedding Of Escherichia Coli O157:H7 In Feedlot Heifers, B. K. Wilson, B. P. Pulsipher, D. L. Step, M. E. Jacob, D. L. Vanoverbeke, C. J. Richards, T. G. Nagaraja, C. R. Krehbiel

Department of Animal Science: Faculty Publications

The inclusion of wet distillers grains plus solubles (WDGS) in feedlot diets has become a common practice in many regions of the United States due to the expanded production of byproducts and fluctuating corn prices related to ethanol production and other factors. In addition, societal concerns over the continued use of antimicrobials in agriculture production combined with an enhanced interest in disease and pathogen prevention in the food supply have led to an increased interest in use of direct-fed microbials (DFM) in growing and finishing cattle. Direct-fed microbials have been shown to improve ADG and feed efficiency, alter ruminal fermentation, …

Effects Of Sorghum Wet Distillers Grains Plus Solubles In Steam-Flaked Corn–Based Finishing Diets On Steer Performance, Carcass Characteristics, And Digestibility Characteristics, E. K. Buttrey, K. H. Noel, F. T. Mccollum Iii, N. A. Cole, L. O. Tedeschi, James C. Macdonald

Department of Animal Science: Faculty Publications

Two studies were conducted to evaluate the effects of sorghum wet distillers grains (SWDGS) in finishing diets on steer performance, carcass characteristics, and nutrient digestibility. In Exp. 1, 240 steers (initial BW = 379 ± 1 kg) were fed steam-flaked corn–based diets with or without 25% SWDGS and 7.5, 10.0, or 12.5% alfalfa hay. There were no effects of alfalfa hay concentration on BW, DMI, ADG, or G:F (P ≥ 0.16). Including SWDGS reduced (P ≤ 0.05) ADG and G:F. Fat thickness decreased (P = 0.03) and DP tended to decrease (P = 0.09) linearly as level of alfalfa hay …

Effects Of Fat And/Or Methionine Hydroxy Analog Added To A Molasses-Urea-Based Supplement On Ruminal And Postruminal Digestion And Duodenal Flow Of Nutrients In Beef Steers Consuming Low-Quality Lovegrass Hay, R. Lopez, G. D. Bernhard, J. E. Guerra-Liera, S. A. Soto-Navarro, L. A. Balstad, M. K. Petersen, D. V. Dhuyvetter, M. S. Brown, C. R. Krehbiel

Department of Animal Science: Faculty Publications

Five crossbred beef steers (initial BW = 338.6 ± 7.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design experiment to evaluate the effects of methionine hydroxy analog (MHA) and/or yellow grease (fat) added to a molassesurea- based supplement on intake and characteristics of digestion. Steers were fed low-quality hay (long-stem lovegrass Eragrostis curvula: 3.3% CP, 76.8% NDF; DM basis) ad libitum and supplemented with 0.91 kg/d (as fed) of 1 of 4 supplements in a 2 × 2 + 1 factorial arrangement of treatments. Supplemental treatments were 1) control (no supplement, …

Genetic Parameters For Docility, Weaning Weight, Yearling Weight, And Intramuscular Fat Percentage In Hereford Cattle, J. A. Torres-Vázquez, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Cattle behavior, including measures of docility, is important to beef cattle producers not only from a human safety perspective but also due to potential correlations to economically relevant traits. Field data from the American Hereford Association was used to estimate genetic parameters for chute score (CS; n = 25,037), weaning weight (WW; n = 24,908), yearling weight (YW; n = 23,978), and intramuscular fat percentage (IMF; n = 12,566). Single-trait and bivariate animal models were used to estimate heritabilities and genetic correlations. All models included fixed effects of sex and contemporary group, defined as herd–year–season, and direct genetic and residual …