Beef Science Commons^™

Influence Of Increased Supplementation Of Organic-Complexed Zinc To Beef Cows During Gestation: Effects On Preweaning Health Of Offspring, Naija N. Sharpley

Animal Science Undergraduate Honors Theses

The objective of this study was to determine the effect of increasing zinc supplementation from organic-complexed sources to beef cows during gestation on calf performance. In May 2025, during gestation, Angus crossbred cows were confirmed pregnant with female sexed semen (n = 83) and enrolled in the current study. Cows (4.7 ± 2 years of age and 531 ± 84.4 kg body weight, mean ± standard deviation) were allotted to 4 groups (20 to 21 cows/group) based on, sire of heifer calf, cow age, and cow body weights taken at weaning. Assigned groups received 1 of 2 treatments (2 groups/treatment): …

Pbmc Transcriptome Analysis Following Lps Stimulation Reveals Distinct Inflammatory Strategies In Feed-Efficient And Inefficient Beef Cattle, Yarahy Leal

Graduate Theses, Dissertations, and Problem Reports (ETD)

Improving feed efficiency is a primary objective in livestock production, serving as a major driver of profitability and sustainability in beef cattle operations as feed costs continue to rise. Residual feed intake (RFI) and residual average daily gain (RADG) are widely recognized indicators of feed efficiency and are commonly used as selection traits to reduce production costs and environmental impact. Previous research suggests a functional shift in transcriptional activity associated with immunity depending on efficiency phenotype, with evidence of greater immune system robustness in more efficient animals. This dissertation examines the molecular mechanisms linking feed efficiency and immune competence and …

Multi-Omics Analysis Of Immune-Metabolic Adaptation To Direct-Fed Microbial Supplementation In Newly Weaned Beef Steers, Adekunle Odunayo Ajiboye

Graduate Theses, Dissertations, and Problem Reports (ETD)

Immune and metabolic disruption during weaning represents a major challenge to health and productivity in beef cattle. This dissertation tested the hypothesis that supplementation with multi-strain direct-fed microbials (DFMs) modulates immune regulation and metabolic pathways associated with adaptation to weaning stress. To address this, whole-blood transcriptomics and plasma metabolomics were used to evaluate molecular and metabolic responses in newly weaned beef steers during the receiving period. Transcriptomic analysis identified differential expressions of genes associated with immune signaling and inflammatory regulation, indicating modulation of immune-related pathways without changes in growth performance. Metabolomic analysis revealed alterations in circulating metabolites related to amino …

Selecting For Less: How Much Methane Can We Truly Breed Away?, Sean B. Crowley

ORBioM (Open Research BioSciences Meeting)

Background

Genetic selection has potential to reduce enteric methane emissions from cattle, but a key challenge is determining how much of the genetic variation in methane traits is independent of traits already targeted in breeding programs, such as feed intake and growth.

Methods

Methane and carbon dioxide emissions were recorded in 1,700 crossbred, indoor-fed beef cattle using Greenfeed systems. Performance data included feed intake, metabolic liveweight, average daily gain, carcass weight, and ultrasound and skeletal traits. Genetic parameters and correlations among traits were estimated using animal linear mixed models to quantify the independence of methane-related genetic variation.

Results

Daily methane …

Stress And Behavior In Beef Calves During Weaning, Kathleen E. Tierney

Theses and Dissertations

Animal welfare in commercial livestock operations has been an increasing topic of concern. It is well known that stress can have significant behavioral and physiological repercussions. It is especially important in commercial operations to reduce stress, as animal efficiency is the leading priority. In an effort to reduce stress on animals and improve welfare in livestock operations, several studies have evaluated common husbandry practices. One of the most widely studied practices is weaning, which encapsulates the process of removing the young from the dam. Several studies have evaluated the effects of weaning on beef cattle through a variety of behavioral …

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 …

The Importance Of Monitoring Beef Cattle Body Condition, David Secrist

All Current Publications

A body condition scoring system commonly used in the U.S. is an objective effort to quantify a cow’s body condition with ratings from 1 (severely emaciated and weak) to 9 (excessively obese), resulting in a body condition score (BCS). Optimal BCS in commercial cow/calf operation is from 5 to 7, depending on the production stage, feed resources, and the animal’s age. Reproductive efficiency is critical to operational success and is closely tied to BCS. This fact sheet discusses why BCS is important and how to apply BCS to a herd effectively.

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 …

Beefsd: An Integrated And Intensive Extension Curriculum For Beginning Beef Cattle Producers, Krista A. Ehlert, Amanda D. Blair, Stacy Hadrick, Ken Olson

Journal of Extension

There is a strong need to increase the opportunities for and success of the next generation of beef cattle producers. South Dakota State University Extension provides a 2-year educational program called “beefSD;” the purpose is to provide producers with a holistic view of the beef industry, an appreciation for utilizing adaptive management to respond to challenges and opportunities, and skills to assess and manage factors that influence overall operation sustainability. The curriculum has four major components: 1) in person workshops, case studies, interactive webinars, and homework 2) out-of-state learning experiences, 3) ranch to rail program, and 4) networking and mentoring.

Exploring Definitions Of Daily Enteric Methane Emission Phenotypes For Genetic Evaluations Using A Population Of Indoor-Fed Multi-Breed Growing Cattle With Feed Intake Data, Clodgah V. Ryan, Thierry Pabiou, Deirdre C. Purfield, Donagh P. Berry, Stephen Conroy, Craig P. Murphy, Ross Evans

Department of Biological Sciences Publications

Genetic selection has been identified as a promising approach for reducing enteric methane (CH₄) emissions; a prerequisite for genetic evaluations; however, these are estimates of the necessary genetic parameters based on a population representative of where the genetic evaluations will be used. The objective of this study was, therefore, to derive genetic parameters for a series of definitions of CH₄, carbon dioxide (CO₂), and dry matter intake (DMI) as well as genetic correlations between CH₄, CO₂, and DMI in a bid to address the paucity of studies involving methane emissions …

Effects Of Dietary Supplementation Of A Blend Of Saccharomyces Cerevisiae, Multiple Live Probiotic Bacteria, And Their Fermentation Products On Performance, Health, And Rumen Bacterial Community Of Newly Weaned Beef Steers During A 56-D Receiving Period, Emily Treon

Graduate Theses, Dissertations, and Problem Reports (ETD)

We examined the effects of a blend of Saccharomyces cerevisiae, multiple live probiotic bacteria and their fermentation products on performance, health, and the ruminal bacterial community of newly weaned beef steers during a 56-day receiving period. Forty newly weaned Angus crossbred steers (221 ± 25.6 kg BW; 180 ± 17 d of age) were stratified by body weight into four pens (10 steers per pen) such that each pen had a similar average body weight at the beginning of the experiment. The pens were randomly assigned to receive a corn silage basal diet (CON; n = 20) or the …

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 …

Texas A&M Beef Cattle Short Course: Program Evaluation, Nicola Oosthuizen, Pedro Fontes, Graham C. Lamb, Jason J. Cleere

Journal of Extension

Survey results (n = 3,748) collected over a period of 7 years from the Texas A&M Beef Cattle Short Course (BCSC) were analyzed to evaluate course demographics and the impact of the course on attendees. Results of this survey demonstrate that attendee demographics of the BCSC are representative of beef cattle producers in the United States and that the BCSC is effective at delivering information that positively impacts beef production in Texas. Extension professionals can make use of these findings to tailor future education programs to better serve the needs of beef cattle producers nation-wide.

Effect Of Soy Co-Products In Supplements For Grazing Cattle On Growth, Complete Blood Cell Counts, And Physiological Response Following A Lipopolysaccharide Challenge, Bralee Lansdell

Biological Sciences Undergraduate Honors Theses

The objective of this study was to determine the effect of soy co-products (soybean meal and soy oil) in the diet on the growth and hemocytology of cattle during a 56-day growing phase and the physiological/behavioral response to an endotoxin challenge. Angus crossbred steers (n = 36; 289 ± 31 kg, initial body weight ± SD) were stratified by body weight and sire; and assigned randomly to pastures (n = 9; 0.45 ha/mixed-grass pasture). Pastures were assigned randomly to 1 of 3 dietary treatments: 1) a control supplement containing no soy co-products, 2) a supplement containing soybean meal, or 3) …

Increasing Efficiency Of Finishing Beef Production: Strategies To Optimize Starch Digestion, Improve Flake Quality, And Reduce Methane Emissions, Ronald J. Trotta

Theses and Dissertations--Animal and Food Sciences

To continue to meet the demands of increasing food production and environmental sustainability, new strategies are needed to enhance the efficiency of finishing cattle production. A review of the literature identified several nutritional and physiological constraints that limit the ability for cattle to digest starch and absorb glucose from the small intestine. Comparative sequencing analyses revealed a missing region of the sucrase-isomaltase protein which could affect the capacity for starch digestion in cattle. Post-flaking sampling and handling recommendations were generated based on a series of experiments to improve estimates of starch availability and flaking consistency for commercial feedlots and laboratories. …

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 …

The Benefits Of Growth-Promoting Implants For Beef Cattle, Caleb C. Reichhardt, Reganne K. Briggs, Laura Motsinger, Kara Thornton-Kurth, Matthew D. Garcia

All Current Publications

Growth-promoting implants have been used in the cattle industry for decades. Their benefits allow cattle producers to become more sustainable by decreasing the amount of resources used. Resources such as water and land are decreased when using growth-promoting implants in beef cattle.

Clearing The Air Between Methane And Commercial Beef Cattle In Ireland, Clodagh V. Ryan

ORBioM (Open Research BioSciences Meeting)

Background

Rumen methanogenesis is the single most significant source of anthropogenic methane (CH₄) emissions. This research aimed to analyse CH₄ data recorded by GreenFeed systems by assessing the repeatability of such phenotypic measures, estimating the heritability of CH₄, and generating CH₄ estimated breeding values (EBVs) for inclusion in the national breeding index_.

Methods

CH₄ measurements were recorded on 979 cattle for 20 to 83 days using GreenFeed machines, resulting in 211,136 individual CH₄ observations. The phenotypic repeatability of CH₄ was estimated for six different averaging periods using a linear mixed …

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 …

Interaction Of Replacing Corn Silage With Soyhulls As A Roughage Source With Or Without 3% Added Wheat Straw In The Diet: Impacts On Intake, Digestibility, And Ruminal Fermentation In Steers Fed High-Concentrate Diets, Bryan W. Neville, Wayde J. Pickinpaugh, Lea J. Mittleider, Rebecca L. Moore, Kendall C. Swanson, Joel S. Caton

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

Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the …

Impacts Of Added Roughage On Growth Performance, Digestibility, Ruminal Fermentation, And Ruminal Ph Of Feedlot Steers Fed Wheat-Based Feedlot Diets Containing 30% Modified Distillers Grains With Solubles, Wayde J. Pickinpaugh, Bryan W. Neville, Rebecca L. Moore, Joel S. Caton

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

Two experiments were conducted to evaluate the inclusion rate roughage in wheat-based diets containing modified distillers grains with solubles (MDGS) on feedlot performance (Feedlot Experiment), as well as digestibility, ruminal pH, and ruminal fermentation characteristics (Digestibility Experiment). The feedlot experiment utilized 72 Angus steers (392 ± 46.3 kg initial body weight) which were randomly assigned to 1 of 12 pens, 3 pens per treatment, to evaluate feedlot performance and carcass characteristics. Dietary treatments were 1) control; 10% roughage, 2) 12% roughage, 3) 14% roughage, and 4) 16% roughage. The digestibility experiment used four ruminally and duodenally cannulated steers (393 ± …

Impact Of Wood-Sourced Biochar On Carbon And Nitrogen Capture In Beef Feedlot Systems, Jessica L. Sperber

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

A feedlot growing and finishing experiment evaluated the effect of including pine-sourced biochar at 0.8 (growing) and 1.0% (finishing) of dietary DM on steer performance, carcass characteristics, and greenhouse gas (GHG) production (Exp 1). Two nutrient mass balance experiments were conducted during winter and summer seasons to evaluate the effect of spreading unprocessed red cedar biochar on the feedlot pen surface on manure nutrient capture and cattle performance (Exp 2). In Exp. 1, the inclusion of biochar in the growing diet did not impact steer performance. The inclusion of biochar in the finishing diet significantly reduced intake and gain, resulting …

Mosaic Agriculture: A Guide To Irrigated Crop And Forage Production In Northern Wa, Geoff A. Moore Mr, Clinton K. Revell Dr, Christopher Schelfhout Dr, Christopher Ham Mr, Samuel Crouch Mr, Meredith M. Guthrie

Bulletins 4000 -

The Bulletin is a comprehensive guide for pastoralists, agronomists, agribusiness and the broader community on the growing of irrigated crops and pastures within a rangeland pastoral setting.

Dispersed irrigation developments on stations throughout the northern rangelands (sometimes referred to as mosaic agriculture) has created opportunities for the introduction of more productive forage species and pastoralists can now grow high quality forage for 12 months of the year. This can help to overcome the key constraint of traditional pastoral systems, the low quality of the feed over the dry season that typically results in stock losing condition.

Assessment Of Alternative Models For Genetic Analysis Of Worm And Tick Infestation In Nellore Cattle, T. L. Passafaro, F. B. Lopes, Thomas W. Murphy, B. D. Valente, R. C. Leite, G. J.M. Rosa, F. L.B. Toral

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

Worms and ticks are important parasites in beef cattle, especially in tropical areas, causing significant economic and production losses. Understanding animal-to-animal variation on infestation for these parasites might guide genetic selection and improvement of management practices to attenuate its detrimental effects. Statistical models used to analyze such traits usually assume a Gaussian distribution for the observed data. However, this assumption is quite often inappropriate for counting data. Therefore, the objectives of this study were: 1) Estimate genetic parameters for worms and tick infestations in Nellore cattle, and 2) To compare the overall performance of six data analysis approaches for worm …

Genetic Changes In Beef Cow Traits Following Selection For Calving Ease, Gary L. Bennett, Richard M. Thallman, Warren M. Snelling, John W. Keele, Harvey C. Freetly, Larry A. Kuehn

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

One approach to reducing calving difficulty is to select heifers with higher breeding value for calving ease. Calving ease is often associated with lower birth weight and that may result in other possible effects on lifetime productivity. Females from experimental select and control calving ease lines within each of the seven populations were compared. Random samples of 720 heifers from lines selected for better calving ease breeding values and 190 heifers from control lines selected for average birth weights were followed through four parities. Select and control lines within the same population were selected to achieve similar yearling weight breeding …

Exploring How Maternal Phosphorus Status Affects Calf Growth And Performance, Elizabeth Lafferty, Beth Kegley, Brittni Littlejohn, Jeremy Powell

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Phosphorus is an important component of bodily functions and is critical for adequate growth and development. This experiment evaluated the effect of maternal phosphorus intake on the growth and health of the calves. Treatments were 1) a free-choice mineral containing no supplemental P or 2) a free-choice mineral with 4% supplemental phosphorus. Primiparous, or pregnant for the first time, crossbred Angus beef cows (n = 36) were stratified by body weight and pregnancy status (bred by artificial insemination or natural service) then assigned to pasture groups (4 groups, 2/treatment, 9 heifers/group). These bred heifers had been receiving these same dietary …

Influence Of Dietary Manipulation On The Relationship Between Temperament Measures And Growth In Beef Cattle: Endophyte Exposure, Phytogenic Supplementation, And Controlled Feeding, Paul Shanks

Theses and Dissertations--Animal and Food Sciences

The influence of dietary factors (including endophyte exposure, phytogenic supplementation, and controlled feeding) on relationships between exit velocity (EV), growth performance in grazing and finishing cattle, and carcass characteristics were explored. Two grazing studies were conducted evaluating EV effects on cattle grazing both toxic and nontoxic endophyte-infected tall fescue. Cattle were followed through two subsequent finishing studies and an additional beef cattle finishing beef cattle study was also conducted. Results from these studies agree with many literature reports indicating that EV measures relate to growth performance and associated carcass traits in beef cattle being fed high energy diets in confinement, …

Analyzing The Management Practices Of East Texas Beef Cattle Producers, Hiliary Cheyenne Swor

Electronic Theses and Dissertations

A survey of East Texas beef cattle producers was designed to evaluate the management practices that were prevalent in the area. Demographic and cattle operation data from 103 respondents were analyzed using SPSS (Version 25; Chicago, IL). This electronic-based survey was distributed through Qualtrics. Respondents were located in Angelina, Nacogdoches, or Cherokee county. Most producers (38.8%) had a Bachelor’s degree. A negative correlation was established between castration method and weaning weight (p = - 0.204). Calves were weaned 50 pounds heavier when band or surgically castrated. Females were less likely to castrate their calves or utilize a mineral program. Approximately, …

The Effects Of Excess Dietary Sulfur Using Supplemental Sodium Sulfate On Beef Steer, Heifer, And Progeny Productive And Physiological Responses, Jamie Hawley

Graduate Theses and Dissertations

For studies 1 through 3, 20 steers of predominantly Angus breeding, were stratified by body weight (279 ± 13.2 kg), assigned randomly to 6 paddocks, and fed a low S ground corn and soybean meal supplement that did not contain any byproduct feeds (0.31% total dietary S; LS) or LS supplement with an additional 0.25% S provided from sodium sulfate (Na2SO4; 0.58% total dietary S; HS) for a 114-d growing phase. Steers were moved to feedlot (373 ± 0.2 kg), remained on prior dietary S treatments, and fed corn and soybean meal diets (0.19 and 0.42% total dietary S; LS …