Beef Science Commons^™

Relationship Between Host Genomics And Microbiomics In Beef Cattle, Andrew D. Lakamp

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

As sequencing technology becomes more affordable and throughput increases, microbiome information is becoming more readily available. For beef cattle selection, microbial information has a variety of uses including being a target for genetic prediction or used as a means to explicitly describe additional phenotypic variability in other traits.

Infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, is a disease that infects the ocular surface and surrounding tissue which is an animal health and producer economic concern. Vaccinations have shown to have variable effectiveness, while limited genetics studies have suggested that direct genetic selection for resistance would be slow. Therefore, an …

Small Beef-Packer Resilience During The Covid-19 Pandemic: Evidence And Policy Implications, Azzeddine Azzam, Sunil P. Dhoubadel, Binod Khanal

Cornhusker Economics

As part of a larger research project on the economics of beef supply chain resilience to natural disasters, financed in part by a grant from the USDA National Institute of Food and Agriculture, we obtained information from 289 processing plants across the United States about their operations during the peak COVID-19 period of March to June 2020 via a telephone survey. We collected data on plant type (slaughter, processing, both), the dominant livestock processed by the plant (predominantly beef, pork, poultry, and sheep/goat), plant capacity (maximum and typical capacity in slaughter head/day), age of establishment, and, whether the plant ceased, …

Heat Stress Changes The Bovine Methylome And Transcriptome And Investigation Of Two Novel Genetic Defects In Cattle, Rachel Renae Reith

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

Heat stress is a major concern for livestock producers due to its negative impact on animal health and productivity. Heat stress does so by altering expression of genes through different regulatory mechanisms such as DNA methylation. Understanding how heat stress alters gene expression will help elucidate the genetic basis of physiological changes as well as identify targets for possible heat stress mitigation. The purpose of the first study was to understand how heat stress alters the adipose and skeletal muscle transcriptomes in zilpaterol-fed Brahman, as zilpaterol improves muscle growth and may mitigate the effects of heat stress. Differential expression and …

Heat Stress Changes The Bovine Methylome And Transcriptome And Investigation Of Two Novel Genetic Defects In Cattle, Rachel Renae Reith

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Heat stress is a major concern for livestock producers due to its negative impact on animal health and productivity. Heat stress does so by altering expression of genes through different regulatory mechanisms such as DNA methylation. Understanding how heat stress alters gene expression will help elucidate the genetic basis of physiological changes as well as identify targets for possible heat stress mitigation. The purpose of the first study was to understand how heat stress alters the adipose and skeletal muscle transcriptomes in zilpaterol-fed Brahman, as zilpaterol improves muscle growth and may mitigate the effects of heat stress. Differential expression and …

The Impact Of A Pgym Variant On Myophosphorylase Deficiency In Red Angus Composite Cattle And Changes In The Skeletal Muscle Transcriptome Due To The Intramuscular Administration Of Lidocaine In Wether Lambs, Mackenzie Christin Batt

School of Biological Sciences: Dissertations, Theses, and Student Research

Project 1 focused on eight calves in a Nebraska herd (composite Simmental, Red Angus, Gelbvieh) that displayed exercise intolerance during forced activity. Available sire pedigrees contained a paternal ancestor within 2-4 generations in all affected calves. Pedigrees of the calves’ dams were unavailable, however, the cows were ranch-raised and retained from prior breeding seasons, where bulls used for breeding occasionally had a common ancestor. Therefore, it was hypothesized that a de novo autosomal recessive variant was causative of exercise intolerance in these calves. A genome-wide association analysis followed by whole-genome sequencing led to the identification of a variant in the …

Impact Of Strategic Postweaning Supplementation On March- And May-Born Yearling Range Heifer And Calf Growth And Performance In The Nebraska Sandhills, Josie Nicole Crouch

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

Three experiments were conducted at the Gudmundsen Sandhills laboratory near Whitman, Nebraska. Experiment 1, a retrospective regression analysis, evaluated the impact of heifer percentage of mature body weight (BW) at breeding on heifer performance, subsequent pregnancy rates, and calf production. Overall pregnancy rates were greater (P < 0.01) for heifers at 60 to 70% of mature BW than 50 to 55%, with no differences in pregnancy rates (P ≥ 0.15) after 2-years of age. Heifers at 50 to 60% of mature BW had a greater (P = 0.05) proportion give birth in the first 21-d. A higher percentage of mature BW at breeding resulted in greater (P < 0.01) BW at birth and weaning for offspring.

Experiments 2 and 3 were 3-year studies that evaluated the impact …

Artificial Insemination And Fetal Programming In Beef Production Systems, Dempster M. Christenson

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

Pregnancy to artificial insemination and late gestation fetal programming of the next calf crop are central to genetic development, reproductive longevity, calf crop productivity, and efficiency of cow/calf ranching. The purposes of this research are to find methods to improve pregnancy rate to artificial insemination, the growth and reproductive health of pregnant heifers, and the productivity of their offspring. In the first of four studies we found that extending the period of progesterone administration in an estrus synchronization protocol did not significantly hasten estrus response or increase pregnancy rate to artificial insemination, but timing of estrus within the melengestrol acetate …

Program Requirements For Beef Cattle Certified As Usda Organic, Carsten Loseke, Elliott James Dennis

Cornhusker Economics

This document provides an overview of the use and production of the USDA Certified Organic program for the beef cattle industry, with an emphasis on the state of Nebraska. We detail what cattle qualify, feed requirements, medical and health standards of cattle, and premiums paid by consumers for USDA certified organic products. All information is taken from the Organic Foods Production Act Provisions available in the Federal Register.

Adding Value To Crop Production Systems By Integrating Forage Cover Crop Grazing, Robert B. Mitchell, Daren D. Redfearn, Kenneth P. Vogel, Terry J. Klopfenstein, Galen Erickson, P. Steven Baenziger, Bruce E. Anderson, Mary E. Drewnoski, Jay Parsons, Steven D. Masterson, Marty R. Schmer, Virginia L. Jin

Department of Agronomy and Horticulture: Faculty Publications

In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance was compared in the spring following autumn establishment as for age cover crops after soybean [Glycine max (L.) Merr.] grain harvest. Replicated pastures (0.4 ha) were no-till seeded in three consecutive years into soybean stubble in autumn, fertilized, and grazed the following spring near Ithaca, Nebraska, USA. Each pasture (n = 3) was continuously stocked in spring with four yearling steers (380 ± 38 kg) for …

Predicting Body Weight Of Cattle And Nutrient Digestion Of Individual Sweet Bran Components To Improve Beef Cattle Production Efficiency, Dalton J. Anderson

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

Efficiency is of high importance to beef cattle producers to ensure that beef cattle are being raised without unnecessary resource use. Two separate experiments were conducted to evaluate potential strategies to improve efficiency in beef cattle production. A metabolism study was conducted to evaluate digestion parameters of individual Sweet Bran components. The objective was to determine the effects of diet components on nutrient digestion and rumen fermentation parameters. The individual components of Sweet Bran (Corn bran, solvent-extracted germ meal, and corn steep liquor) were included at 40% diet dry matter (DM) in a steam-flaked corn (SFC) based diet. A SFC-based …

Investigation Of Breeding Objectives And Indexes-In-Retrospect, Hunter F. Valasek

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

This thesis presents two projects that investigate the impacts of breeding objectives and indexes-in-retrospect within the beef cattle industry. The first project synthesized how changes due to planning horizon, breeding system, and sale endpoint in the economic breeding goal of cattle influence the relative emphasis of traits as well as the re-ranking of selection candidates. A total of three breeding systems that represent straightbred and crossbred cattle were used along with six planning horizons (2, 5, 10, 20, 30, and 50 yrs.) for both a weaning and slaughter point of sale. The combination of these different breeding objective attributes resulted …

The Evaluation Of Feed Additives On Reducing Enteric Methane Production From Cattle, Reba L. Colin

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

Environmental sustainability can be positively impacted by the inclusion of feed additives to reduce enteric methane production from cattle. Methane production can be affected by feed additives that either alter the rumen environment or act as methanogenesis inhibitors. A reduction in methane from cattle can contribute to meeting carbon neutrality.

A metabolism study was conducted to evaluate Alga 1.0, a product containing bromoform, fed to cattle to evaluate the effects on gas emissions. Treatments were (0, 69, or 103 g/d Alga 1.0) fed in a corn-based diet. Headbox-style indirect calorimeters were used to measure gas emissions. Feeding Alga 1.0 linearly …

The Impact Of Silage Inclusion In Diets With Different Corn Processing And The Effect Of Natural And Conventional Feeding Programs On Finishing Cattle Performance, Jessica L. Miller

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

A finishing experiment was conducted to determine the effects of natural and conventional feeding programs on finishing performance of steers and heifers. Factors were conventional and natural feeding programs in steers and heifers. Cattle assigned to the conventional program were fed diets that contained Rumensin (Elanco Animal Health), Tylan (Elanco Animal Health), MGA (Zoetis), and received growth promoting implants whereas cattle in the natural program received neither. Compared to natural fed cattle, G:F was improved by 15.5% when heifers were fed in a conventional program (P < 0.01) and 23.8% when steers were fed in a conventional program (P < 0.01). The incorporation of implants and feed additives within the finishing period increased …

Forages And Technology Management In Growing And Finishing Beef Cattle Systems, Kelton Cole Adair

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

A systems study evaluated the effects of an implant [25.7 mg estradiol (Compudose; Elanco Animal Health)] at two rates of gain (LOW: 0.45 kg/d and HIGH: 0.9 kg/d) applied during the winter backgrounding phase in drylot and winter grazing systems and its effects on subsequent phases of production. HIGH supplementation with an implant during the winter backgrounding phase in the drylot system yielded the greatest ending body weight (EBW) during the summer backgrounding phase (P = 0.04). LOW supplementation, without an implant, improved summer backgrounding average daily gain (ADG; P = 0.05) while achieving similar carcass adjusted final body …

Dry-Aged Beef Flavor Development, And The Effect Of High Levels Of Vitamin-E On Beef Color Stability, Nicolas Herrera

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

Palatability and consumer purchasing are essential factors of fresh meat. To meet consumer expectations during purchasing and consumption, fresh beef must maintain desirable cherry-red color at retail and achieve desirable cooked flavor. Dry-aged beef popularity has grown, and identifying methods to ensure quality dry-aged meat is necessary to maintain demand. To understand dry-aged palatability, this dissertation addressed effects of moisture loss and aging time, fundamental factors of dry-aged beef, using bone-in and boneless strip loins. Study two investigated flavor development using cookery methods and internal temperatures in boneless and bone-in dry-aged beef. In study one, increased dry-aging time (creation effect) …

Consequences Of Cow–Calf Production With Limited Perennial Forage Grazing, Hannah Fae Speer

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

Conversion of perennial grasslands to cropland and rising land prices prompts a need to evaluate alternative beef cow-calf production systems. A 3-yr study was conducted comparing beef cow-calf performance between two August-calving cow systems: perennial forage and corn residue grazing; or summer drylot, fall grazing of late-summer-planted cover crop, and corn residue grazing. Cow body condition score differed between systems, but condition of cows in both systems never fell below adequate. There were no differences in pregnancy rates between systems. Calf weaning weights differed between systems each year; differences are attributed to feedstuff quantity, quality, and type available to calves …

Effect Of Supplementation Prior To Artificial Insemination And During Gestation In Beef Females, Landon Folsom Tadich

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

Objectives of Experiment 1 was to evaluate the impact of increased energy prior to AI on BW, ADG, and reproductive efficiency in heifers developed on range or in a dry lot. During the winter development period (131 ± 3.5 d/yr) heifers (n = 100/yr) were assigned to either upland range (RANGE) or fed a dry lot diet in two pens that either remained constant (DLLO) or increased in energy prior to AI (DLHI). Heifers developed on RANGE grazed upland winter range until 38 d prior to AI where they then received the DLLO diet. Pre-breeding BW was greater ( …

Methods To Reduce Nitrogen And Carbon Losses From Finishing Beef Cattle, Hanna K. Cronk

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

A finishing experiment evaluated the effect of incremental supplemental rumen-protected lysine on beef cattle performance. All cattle were fed the same diet of high moisture corn, dried rolled corn, modified distillers grains plus solubles, corn silage, and supplement with inclusion levels of lysine ranging from 0 to 7 grams/day, in 1 g increments. Dry matter intake (P ≤ 0.04) and ADG (P ≤ 0.04) decreased linearly as supplemental lysine increased in the diet with no effect on final carcass adjusted feed efficiency (P ≥ 0.34). In the initial 64 days of the experiment, increasing lysine in the …

Heifers On Feed Indicate Long-Term Liquidation Still Occurring, Elliott James Dennis

Cornhusker Economics

This article was first published in the Livestock Marketing Information Centers' (LMIC) In the Cattle Markets newsletter on January 9, 2023.

Combining the historical quarterly percentage of heifers on feed and cattle inventory report can provide an indicator of how many heifers will be held back for replacement in the 2023 report.

Range Beef Cow Symposium Xxvii Proceedings, 2023, Loveland, Colorado

Range Beef Cow Symposium

2023—Range Beef Cow Symposium XXVIII, Loveland, Colorado, presented by the Cooperative Extension Services and Animal Science Departments of University of Wyoming, Colorado State University, South Dakota State University, and University of Nebraska-Lincoln.

Marketing Feeder Calves for Increased Value, Darrell S. Peel, Oklahoma State University

Principles for Successful Livestock Grazing Management on Western Rangelands, K. E. Jablonski and K. R. Stackhouse-Lawson, Colorado State University

Ionophores and Reproduction: What is the Benefit for Range Cows and Heifers? J. Travis Mulliniks and Juliana Ranches, Oregon State University, Jacki A.Musgrave and Kacie L.McCarthy, University of Nebraska-Lincoln

Should We Be Supplementing More Vitamin A to …

Impacts Of Feeding Biochar To Beef Cattle On Greenhouse Gas Emissions And Performance And Characterizing Yearling Steers Grazing Smooth Bromegrass Pasture Using Gps, Holly A. Heil

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

As global warming continues to rise, the pressure and growing demand for sustainable animal production is increasing. Livestock naturally produce greenhouse gas emissions through enteric fermentation. Dietary manipulation strategies have been sought out to decrease emissions in ruminants using feed additives.

Two independent finishing feedlot experiments evaluated two types of biochar and its effects on animal performance, carcass characteristics and greenhouse gas emissions. Experiment 1 utilized pistachio shell biochar and experiment 2 utilized biochar sourced from ponderosa pine wood waste, both types included at 1% of the diet DM. The addition of biochar to the diet did not impact animal …

Variance Component Estimates For Growth Traits In Beef Cattle Using Selected Variants From Imputed Low-Pass Sequence Data, Chad A. Russell

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

A beef cattle population (n = 2,343) was used to assess the impact of variants identified from imputed low-pass sequence (LPS) on the estimation of variance components and genetic parameters of birth weight (BWT) and post weaning gain (PWG). Variants were selected based on functional impact and were partitioned into four groups (Low, Modifier, Moderate, High) based on predicted functional consequences and re-partitioned based on consequence of mutation, such as missense and untranslated region variants, into six groups (G1-G6). Each subset was used to construct a genomic relationship matrix (GRM) for univariate animal models. Multiple analyses were conducted to …

Microbial Community Structure From Southern High Plains Beef Cattle Feedyard Manure And Relationship With Nitrous Oxide Emissions, Heidi Waldrip, David Parker, Sierra Miller, Lisa M. Durso, Byeng R. Min, Daniel N. Miller, Kenneth Casey, Bryan Woodbury, Mindy J. Spiehs

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Modern molecular techniques enable characterization of the microbial biome in livestock manure, from which there is particular concern over emission of greenhouse gases. This study evaluated how sampling depth, time, temperature, and artificial rainfall affected microbial community structure in feedyard manure, and relationships between the manure biome and known parameters related to nitrous oxide (N₂O) emissions. In three large incubation chambers, maintained at different temperatures that received two applications of artificial rainfall, we evaluated manure microbiome composition and abundance of N₂O-producing enzymes (nirK and nirS) using quantitative polymerase chain reaction (qPCR). These data were …

Investigating Bacterial Community Composition And Antimicrobial Resistance Genes In Beef Cattle, Arena E. See

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

While antibiotics have been critical over the last decade for curbing infectious diseases, they have contributed to the rise of antimicrobial resistance (AMR). Infections resulting from antimicrobial-resistant pathogens are correlated with severe morbidity, mortality, and healthcare costs. With the increasing concerns regarding AMR and its emergence, it is paramount to understand not only the effects of antibiotics on microbial community and diversity, but also to develop a novel tool that gives us a better understanding of the spread and functional traits of AMR genes.

To this end, rumen, fecal, and pen surface samples were collected from 72 animals at United …

Use Of Livestock Risk Protection Insurance For Cattle Continues To Grow, Jay Parsons

Cornhusker Economics

When used as a regular part of a market risk management plan, livestock risk protection (LRP) insurance can help protect profits in years where markets turn for the worse. The recent changes to the program have made LRP insurance more appealing to cattle producers and sales of LRP have subsequently increased dramatically. Strong price increases may make LRP unnecessary, but it is difficult to predict when the price increases will end. LRP insurance is a safety net, reducing downside price risk by providing a floor on national price expectations while also allowing producers to take advantage of higher national prices …

Evaluating The Shelf Life And Sensory Properties Of Beef Steaks From Cattle Raised On Different Grass Feeding Systems In The Western United States, Toni L. Duarte, Bakytzhan Bolkenov, Sarah C. Klopatek, James W. Oltjen, D. Andy King, Steven D. Shackelford, Tommy L. Wheeler, Xiang Yang

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Consumer interest in grass-fed beef has been steadily rising due to consumer perception of its potential benefits. This interest has led to a growing demand for niche market beef, particularly in the western United States. Therefore, the objective of this study was to assess the impact of feeding systems on the change in microbial counts, color, and lipid oxidation of steaks during retail display, and on their sensory attributes. The systems included: conventional grain-fed (CON), 20 months-grass-fed (20GF), 25-months-grass-fed (25GF) and 20-months-grass-fed + 45-day-grain-fed (45GR). The results indicate that steaks in the 20GF group displayed a darker lean and fat …

The Impact Of Steam-Flaked Rye Replacing Steam-Flaked Corn On Performance And Carcass Characteristics Of Yearling Steers And The Effect Of Exogenous Megasphaera Elsdenii Administration Techniques On Ruminal Fermentation And Blood Parameters In An Acidosis Challenge Model, Samantha K. Wagner

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

A feedlot study was conducted to evaluate the effects of replacing steam-flaked corn (SFC) with steam-flaked rye (SFR) in the diets of yearling steers (Exp. 1). A separate study was conducted to evaluate the effects of three different administration techniques of Megasphaera elsdenii NCIMB 41125 on rumen fermentation and blood parameters in an acidosis challenge model (Exp. 2). In Exp. 1, SFC was replaced with SFR to create four different treatments, each differing in the ratio of SFC:SFR. The four treatments were 0:100, 25:75, 50:50, and 100:0 SFR:SFC (as a percentage of the grain inclusion). Increasing inclusions of SFR resulted …

Genes Involved In Feed Efficiency Identified In A Meta-Analysis Of Rumen Tissue From Two Populations Of Beef Steers, Amanda K. Lindholm-Perry, Allison M. Meyer, Rebecca J. Kern-Lunbery, Hannah C. Cunningham-Hollinger, Taran H. Funk, Brittney N. Keel

Roman L. Hruska U.S. Meat Animal Research Center: Reports

In cattle, the rumen is an important site for the absorption of feed by-products released by bacterial fermentation, and variation in ruminal function plays a role in cattle feed efficiency. Studies evaluating gene expression in the rumen tissue have been performed prior to this. However, validating the expression of genes identified in additional cattle populations has been challenging. The purpose of this study was to perform a meta-analysis of the ruminal transcriptome of two unrelated populations of animals to identify genes that are involved in feed efficiency across populations. RNAseq data from animals with high and low residual feed intake …

Prenatal Transportation Stress Did Not Impact Ovarian Follicle Count For Three Generations Of Female Brahman Offspring, Lacey K. Quail, Ronald D. Randel, Thomas H. Welsh Jr., Robert A. Cushman, Hannah K. Yake, Rui A. D'Orey Branco, Donald A. Neuendorff, Charles R. Long, George A. Perry

Roman L. Hruska U.S. Meat Animal Research Center: Reports

As prenatal transportation stress altered behavior and adrenal glucocorticoid secretion of calves, we hypothesized that prenatal transportation stress would decrease ovarian reserve size and negatively impact female offspring fertility. The impact of prenatal transportation stress on ovarian follicle numbers in female offspring for three generations was studied. Brahman cows were transported for 2 h on day 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 of gestation. Ovaries were collected from offspring of transported or non-transported dams at multiple ages. Primordial, primary, secondary, and antral follicles were histologically analyzed. Antral follicle numbers were …

Efficacy Of Antimicrobial Interventions Used In Meat Processing Plants Against Antimicrobial Tolerant Non–Antibiotic-Resistant And Antibiotic-Resistant Salmonella On Fresh Beef, Norasak Kalchayanand, Sapna Chitlapilly Dass, Yangjunna Zhang, Eric L. Oliver, Bing Wang, Tommy L. Wheeler

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Salmonella is a common cause of foodborne illness in the United States, and several strains of Salmonella have been identified as resistant to antibiotics. It is not known whether strains that are antibiotic resistant (ABR) and that have some tolerance to antimicrobial compounds are also able to resist the inactivation effects of antimicrobial interventions used in fresh meat processing. Sixty-eight Salmonella isolates (non-ABR and ABR strains) were treated with half concentrations of lactic acid (LA), peracetic acid (PAA), and cetylpyridinium chloride (CPC), which are used in beef processing plants to screen for tolerant strains. Six strains each from non-ABR and …