Genetics and Genomics Commons^™

Development Of Genetic Goat And Hamster Models Of Atrial Fibrillation And Long Qt Syndrome; And Genetic Hamster Models Of Middle East Respiratory Syndrome, Dane A. Rasmussen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Atrial fibrillation (AF) and long QT syndrome (LQTS) are potentially lethal heart rhythm disorders that can be caused by mutations in the potassium channel gene KCNQ1. Middle East Respiratory Syndrome (MERS) is a viral infection with the potential to replicate the devastating effects of the SARS outbreak in 2003. All three of these diseases are in need of genetic animal models.

To address these needs, my thesis project focused on the development of genetic goat and hamster models of AF and LQTS, and genetic hamster models of MERS. Because of the goat’s similar organ size/physiology and the hamster’s similar lipid …

Divergent Selection For Four-Day Relative Breast Yield And The Effect Of Thermal Manipulations On Growth Characteristics On Lines Selected For Different Processing Dates., James Grant Mason

Graduate Theses and Dissertations

Genetic selections currently utilized in the poultry industry have been highly successful in promoting broiler growth rate and yield. However, these selections may have come at the expense of broiler physiology, as evidenced by an increase in physiological disorders. To address this experimentation was undergone to develop a novel method of selection to promote growth with minimal physiological impact and to assess how a new embryonic technique affects growth in broiler lines exhibiting different growth rates.

In the first experiment, a random bred control (RAN) broiler line was divergently selected for four-day relative breast yield (BY4) resulting in the high …

Relative Abundances Of The Recently Introduced Barnacles, Megabalanus Coccopoma And An Unidentified Species Of Megabalanus, In The Southeastern U.S., Jennifer L. Tyson

Honors College Theses

ABSTRACT

Megabalanus coccopoma is a prominent invasive species off the coast of Georgia. Recently, among collected samples thought to be M. coccopoma, several individuals of an unidentified species of barnacle were found. The species has been identified as a Megabalanus species, but is still unidentified to the species level. Species identification is difficult due to morphological variation, inconsistent taxonomic keys, and unknown origin. In this study I developed a method to accurately distinguish M. coccopoma from the unidentified Megabalanus sp. using sequence differences in the mitochondrial Cytochrome Oxidase I (COI) gene. This study will provide an accurate estimate of …

Characteristics Of Trailer Thermal Environment During Commercial Swine Transport Managed Under U.S. Industry Guidelines, Y Xiong, Angela Green, Richard S. Gates

Department of Animal Science: Faculty Publications

Transport is a critical factor in modern pork production and can seriously affect swine welfare. While previous research has explored thermal conditions during transport, the impact of extreme weather conditions on the trailer thermal environment under industry practices has not been well documented; and the critical factors impacting microclimate are not well understood. To assess the trailer microclimate during transport events, an instrumentation system was designed and installed at the central ceiling level, pig level and floor-level in each of six zones inside a commercial swine trailer. Transport environmental data from 34 monitoring trips (approximately 1–4 h in duration each) …

Fisheries Management Paper No.273 - Blue Swimmer Crab Resource Of The Peel-Harvey Estuary Harvest Strategy, 2015-2020. Version 1.0, Department Of Fisheries, Western Australia

Fisheries Management Papers

Harvest strategies for aquatic resources managed by the Western Australian Department of Fisheries (the Department) are formal documents prepared to support the decision-making processes required to ensure the management of these resources are consistent with the principles of Ecologically Sustainable Development (ESD). The objectives of ESD are reflected in the objects of the Fish Resources Management Act 1994 (FRMA), Section 3, and the draft Aquatic Resources Management Bill 2013 (ARMB), Clause 9, which will replace the FRMA once enacted.

The publication of these strategies is intended to make the decision-making considerations and processes for the management of specified aquatic resources …

Sphingolipids Are Required For Efficient Triacylglycerol Loss In Conjugated Linoleic Acid Treated Adipocytes, Wei Wang, Michael E. Fromm

Department of Animal Science: Faculty Publications

Conjugated linoleic acid (CLA) reduces adiposity in human and mouse adipocytes. This outcome is achieved through a variety of biological responses including increased energy expenditure and fatty acid oxidation, increased inflammation, repression of fatty acid biosynthesis, attenuated glucose transport, and apoptosis. In the current study, profiling of 261 metabolites was conducted to gain new insights into the biological pathways responding to CLA in 3T3-L1 adipocytes. Sphinganine and sphingosine levels were observed to be highly elevated in CLA treated adipocytes. Exogenous chemicals that increased endogenous ceramide levels decreased lipid levels in adipocytes, and activated AMP-activated protein kinase (AMPK) as well as …

Genome-Wide Analysis Of Tnf-Alpha Response In Pigs Challenged With Porcine Circovirus 2b, C. A. Kreikemeier, T. B., K. L. Lucot, Thomas E. Burkey, Daniel C. Ciobanu

Department of Animal Science: Faculty Publications

Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine with a role in activating adaptive immunity to viral infections. By inhibiting the capacity of plasmacytoid dendritic cells to produce interferon-α and TNF-α, porcine circovirus 2 (PCV₂) limits the maturation of myeloid dendritic cells and impairs their ability to recognize viral and bacterial antigens. Previously, we reported QTL for viremia and immune response in PCV₂- infected pigs. In this study, we analyzed phenotypic and genetic relationships between TNFα protein levels, a potential indicator of predisposition to PCV₂ co-infection, and PCV₂ susceptibility. Following experimental challenge with …

A Comparison Of The Genetic Diversity Of The Class Ii Major Histocompatibility Complex In Ex Situ And In Situ Populations Of African Penguins (Spheniscus Demersus), Emily Willmer

Undergraduate Honors Thesis Projects

As an endangered species, the African penguin (Spheniscus demersus) is at risk of becoming extinct in the wild due to destruction of their coastal habitat and reduction in food availability. The development of a genetically diverse and healthy captive population is important in helping to conserve the species. The goal of this project was to determine the genetic diversity of the class II major histocompatibility complex (MHC) of a wild population of African penguins and compare it to the diversity of the captive population at Mystic Aquarium in Mystic, Connecticut that has previously been studied. We found that …

Historical And Contemporary Demography Of Leaf-Toed Geckos (Phyllodactylidae: Phyllodactylus) In The Mexican Dry Forest, Christopher Blair, Victor H. Jiménez Arcos, Fausto R. Méndez De La Cruz, Robert W. Murphy

Publications and Research

Disentangling the relative influence of historical versus contemporary processes shaping the spatial distribution of genetic variation is critical if we are to effectively mitigate key biodiversity issues. We utilize a comprehensive approach based on different molecular marker types and analytical methods to understand the demographic consequences of recent habitat fragmentation in a spatially explicit context. We focus our efforts on native leaf-toed geckos (Phyllodactylus tuberculosus saxatilis) throughout fragmented habitat in the tropical dry forest of northern Mexico as recent evidence suggests that geographic ranges for these geckos may be much smaller than currently realized. However, no data are …

Temporal Patterns Of Nutrition Dependence In Secondary Sexual Traits And Their Varying Impacts On Male Mating Success, Malcolm F. Rosenthal, Eileen A. Hebets

Eileen Hebets Publications

Variation in the quantity of nutrients ingested over an individual’s lifetime is likely to differentially affect distinct male secondary sexual traits and courtship signals, potentially providing females with information about a male’s past and present foraging history. We hypothesize that female choice is thus influenced by a male’s lifetime foraging history. To test this, we manipulated the quantity of nutrients (i.e. prey items) available to male wolf spiders, Schizocosa stridulans, using a fully crossed 2 × 2 design with low versus high prey quantity across juvenile and adult life stages, and assessed the impact of these diet treatments on male …

Recurrent Evolution Of Melanism In South American Felids, Alexsandra Schneider, Corneliu Henegar, Kenneth Day, Devin Absher, Constanza Napolitano, Leandro Silveira, Victor A. David, Stephen J. O'Brien, Marilyn Menotti-Raymond, Gregory S. Barsh, Eduardo Eizirik

Biology Faculty Articles

Morphological variation in natural populations is a genomic test bed for studying the interface between molecular evolution and population genetics, but some of the most interesting questions involve non-model organisms that lack well annotated reference genomes. Many felid species exhibit polymorphism for melanism but the relative roles played by genetic drift, natural selection, and interspecies hybridization remain uncertain. We identify mutations of Agouti signaling protein (ASIP) or the Melanocortin 1 receptor (MC1R) as independent causes of melanism in three closely related South American species: the pampas cat (Leopardus colocolo), the kodkod (Leopardus guigna), and Geoffroy’s cat …

Repercussions Of Growth Path On Carcass Characteristics, Meat Colour And Shear Force In Alentejana Bulls, P Costa, J A. Simoes, A S.H. Costa, J P.C. Lemos, D Navas, J F. Hocquette, C R. Calkins, R J.B. Bessa

Department of Animal Science: Faculty Publications

The aim of this study was to evaluate the carcass and meat characteristics of eight muscles from bulls with distinct growth paths. A total of 40 Alentejana male calves were allocated to two distinct feeding regimes. In the continuous growth (CG) system, the animals were fed concentrates plus hay and were slaughtered at 18 months of age. On the other hand, in the discontinuous growth (DG) system, the animals were fed hay until 15 months of age; the cattle were then fed the same diet provided to the CG group from 15 to 24 months of age. The DG reduced …

Loss Of Vascular Endothelial Growth Factor A (Vegfa) Isoforms In Granulosa Cells Using Pdmrt-1-Cre Or Amhr2-Cre Reduces Fertility By Arresting Follicular Development And By Reducing Litter Size In Female Mice, Kevin M. Sargent, Ningxia Lu, Debra T. Clopton, William E. Pohlmeier, Vanessa Brauer, Napoleone Ferrara, David W. Silversides, Andrea S. Cupp

Department of Animal Science: Faculty Publications

Because VEGFA has been implicated in follicle development, the objective of this study was to determine the effects of granulosa- and germ cell-specific VEGFA loss on ovarian morphogenesis, function, and female fertility. pDmrt1-Cre mice were mated to floxed VEGFA mice to develop granulosa-/germ cell-specific knockouts (pDmrt1-Cre;Vegfa^-/-). The time from mating to first parturition was increased when pDmrt1-Cre;Vegfa^-/- females were mated to control males (P = 0.0008) and tended to be longer for heterozygous females (P < 0.07). Litter size was reduced for pDmrt1-Cre;Vegfa^-/- females (P < 0.007). The time between the first and second parturitions was also increased for heterozygous females (P < 0.04) and tended to be increased for pDmrt1-Cre;Vegfa^-/- females (P < 0.07). pDmrt1-Cre;Vegfa^-/- females had smaller ovaries (P …

Estimation Of Breed-Specific Heterosis Effects For Birth, Weaning, And Yearling Weight In Cattle, Lauren N. Schiermiester, R. M. Thallman, Larry Kuehn, Stephen D. Kachman, Matthew L. Spangler

Department of Animal Science: Faculty Publications

Heterosis, assumed proportional to expected breed heterozygosity, was calculated for 6834 individuals with birth, weaning and yearling weight records from Cycle VII and advanced generations of the U.S. Meat Animal Research Center (USMARC) Germplasm Evaluation (GPE) project. Breeds represented in these data included: Angus, Hereford, Red Angus, Charolais, Gelbvieh, Simmental, Limousin and Composite MARC III. Heterosis was further estimated by proportions of British × British (B × B), British × Continental (B × C) and Continental × Continental (C × C) crosses and by breed-specific combinations. Model 1 fitted fixed covariates for heterosis within biological types while Model 2 fitted …

Analysis Of Standard Dna Procedures On Feathers Of Late 19th To Late 20th Century Osprey (Pandion Haliaetus), Alia A. Hamdan, Catherine B. Viverette, Rodney J. Dyer

Rice Rivers Center Research Symposium

Species with well-documented demographic histories and well known perturbations to gene flow provide good models for understanding how historic events impact contemporary population genetic structure1,2. Osprey (Pandion haliaetus), a marine bird-of-prey, experienced steep declines after widespread organochloride pesticide (e.g. DDT) use in the mid-twentieth century 3, however, population genetic consequences remain unknown. Use of historic specimens can aid population genetic studies4,5, however, these samples can degrade over time impacting quantity and quality of extracted DNA5. We compared the concentrations of extracted DNA of Osprey feathers from museum and research collections to those of contemporary samples collected according to standard field …

2015 Oklahoma Research Day Full Program, Northeastern State University

Oklahoma Research Day Abstracts

This document contains all abstracts from the 2015 Oklahoma Research Day held at Northeastern State University.

Technical Note: Collection And Preparation Techniques Change Nutrient Composition Of Masticate Collected From Esophageally Fistulated Cattle, Jacqueline A. Musgrave, J. V. Judy, K. H. Jenkins, T. J. Klopfenstein, L. A. Stalker

Department of Animal Science: Faculty Publications

Two experiments determined effects of collection and preparation techniques on nutrient composition of masticate samples from esophageally fistulated cattle. In Exp. 1, 12 esophageally fistulated cattle were maintained on 2 precollection diets, high CP (24% CP; n = 6) or low CP (7.7% CP; n = 6), for 8 d. On d 9, the esophageal plug was removed, screen bottom bags were attached, and each cow was offered fresh grass. Immediately after fresh grass sample collection was complete, dry grass (hay) was offered and a sample was collected. Blood samples were collected and analyzed for serum urea nitrogen concentration. Masticate …

Dehydrated Citrus Pulp Alters Feedlot Performance Of Crossbred Heifers During The Receiving Period And Modulates Serum Metabolite Concentrations Before And After An Endotoxin Challenge, J. T. Cribbs, B. C. Bernhard, T. R. Young, M. A. Jennings, N.C. Burdick Sanchez, J. A. Carroll, T. R. Callaway, T. B. Schmidt, B. J. Johnson, R. J. Rathmann

Department of Animal Science: Faculty Publications

English × Continental heifers (n = 180) were sourced in 2 loads (219.3 ± 16.0 and 221.4 ± 16.4 kg, respectively) from commercial auction barns to study the effects of feeding dehydrated citrus pulp (DCP) on feedlot performance of newly received heifers. A completely randomized block design was used with BW nested within arrival load and blocked by BW into 3 dietary treatments (36 pens, 5 heifers/ pen, 12 blocks, 3 pens/block, and 12 pens/treatment). Treatment diets contained 1) 0% DCP (control diet [CON]), 2) 10% DCP, or 3) 20% DCP on a DM basis. Diets containing DCP were exchanged …

Case Study: Producer Concerns And Perceptions Regarding The Effect Of Methane On Cattle Production And The Environment: A Survey Of Nebraska Producers, B. M. Boyd, A. Jones, Lisa Franzen-Castle, K. Jenkins, Richard J. Rasby, Matt K. Luebbe, Richard R. Stowell, Samodha C. Fernando, Galen E. Erickson

Department of Animal Science: Faculty Publications

Enteric methane production from cattle and its effect on climate change has been a topic of debate. Multiple studies have explored methods to reduce cattle enteric methane production while simultaneously improving performance. However, most strategies developed have not been widely implemented by cattle producers. Knowledge of producer concerns and perceptions on methane production from cattle and its effect on the environment may be limited. Therefore, the objectives of this survey were to determine what Nebraska producers know about methane production by cattle and how it affects performance and to determine whether different age groups, regions of Nebraska, and production size …

Development Of A Row-Crop Tractor Data Acquisition System, James Roeber, Santosh Pitla, Roger M. Hoy, Joe D. Luck

Department of Animal Science: Faculty Publications

Numerous advancements in machinery performance on row-crop agricultural tractors have been made in recent years. Currently, the Organisation for Economic Co-operation and Development (OECD) only tests predetermined points (E.g., max. power, max. torque) for drawbar and hydraulic power. This method of testing has been used for many years with the tractor at a steady state which is usually not typical of row-crop operations. A data acquisition system (DAQ) was designed that records implement energy consumption (E.g., drawbar loading, PTO power, and hydraulic power). The system used a LabVIEW program and a compact data acquisition system (cDAQ) to record data from …

An Application Of Mesh Enrichment Analysis In Livestock, Gota Morota, F. Moreno, James L. Petersen, Daniel C. Ciobanu, K. Tsuyuzaki, I. Nikaido

Department of Animal Science: Faculty Publications

An integral part of functional genomics studies is to assess the enrichment of specific biological terms in lists of genes found to be playing an important role in biological phenomena. Contrasting the observed frequency of annotated terms with those of the background is at the core of overrepresentation analysis (ORA). Gene Ontology (GO) is a means to consistently classify and annotate gene products and has become a mainstay in ORA. Alternatively, Medical Subject Headings (MeSH) offers a comprehensive life science vocabulary including additional categories that are not covered by GO. Although MeSH is applied predominantly in human and model organism …

Optimizing The Use Of Fibrous Residues In Beef And Dairy Diets, James C. Macdonald, G. E. Erickson, P. J. Kononoff, T. J. Klopfenstein

Department of Animal Science: Faculty Publications

Increased corn prices over the past decade have altered land use away from traditional forage in favor of corn. Accordingly, beef and dairy producers have had to adopt non-traditional forage resources into their production systems, many of which have become available as a result of increased corn production. Byproducts of the wet and dry milling industries have been used to replace both corn and forage in beef and dairy diets. Byproducts containing corn bran have large amounts of readily digestible hemicellulose. The use of byproducts may increase milk production, ADG, and G:F in dairy, beef growing, and beef finishing diets, …

Microbial Diversity And Activity In The Nematostella Vectensis Holobiont: Insights From 16s Rrna Gene Sequencing, Isolate Genomes, And A Pilot-Scale Survey Of Gene Expression, Jia Y. Har, Tim Helbig, Ju H. Lim, Samodha C. Fernando, Adam M. Reitzel, Kevin Penn, Janelle R. Thompson

Department of Animal Science: Faculty Publications

We have characterized the molecular and genomic diversity of the microbiota of the starlet sea anemone Nematostella vectensis, a cnidarian model for comparative developmental and functional biology and a year-round inhabitant of temperate salt marshes. Molecular phylogenetic analysis of 16S rRNA gene clone libraries revealed four ribotypes associated with N. vectensis at multiple locations and times. These associates include two novel ribotypes within the ε-Proteobacterial order Campylobacterales and the Spirochetes, respectively, each sharing 99% 16S rRNA identity with Endozoicomonas elysicola and Pseudomonas oleovorans, respectively. Species-specific PCR revealed that these populations persisted in N. vectensis asecually propagated under laboratory …

Sheep Updates 2015 - Moora, Bruce Mullen, Kate Pritchett, Kimbal Curtis, Daniel Real, Jaq Pearson, Lynne Bradshaw, Geoff Lindon, Katherine Davies, Kevin Hepworth, Stephen Lee, Dawson Bradford, Lucy Anderton, Jackie Jarvis, Ben Patrick

Sheep Updates

This session covers thirteen papers from different authors:

1. The Sheep Industry Business Innovation project, Bruce Mullan, Sheep Industry Development Director, Department of Agriculture and Food, Western Australia

2. Western Australian sheep stocktake, Kate Pritchett and Kimbal Curtis, Research Officers, Department of Agriculture and Food, Western Australia

3. Tedera - a perenial forage legume to reduce your supplementary feeding in summer and autumn, Dr. Daniel Real, Senior Plant Breeder, Department of Agriculture and Food, Western Australia

4. National Livestock Identification System (NLIS) for sheep and goats - what is the NLIS database? Jac Pearson, Biosecurity Officer, Department of Agriculture and …

Sheep Updates 2015 - Katanning, Bruce Mullan, Kate Pritchett, Kimbal Curtis, Chris Wilcox, Mike Hyder, Leigh Sonnerman, Lynne Bradshaw, Geoff Lindon, Katherine Davies, Joe Young, Stephen Lee, Ian Robertson, Lucy Anderton, Hayley Norman, Ed Barrett-Lennard, Jackie Jarvis, Ben Patrick

Sheep Updates

This session covers fourteen papers from different authors:

1. The Sheep Industry Business Innovation project, Bruce Mullan, Sheep Industry Development Director, Department of Agriculture and Food, Western Australia

2. Western Australian sheep stocktake, Kate Pritchett and Kimbal Curtis, Research Officers, Department of Agriculture and Food, Western Australia

3. Wool demand and supply - short term volatility, long term opportunities, Chris Wilcox, Principal of Poimena Analysis

4. Lifetime management for maternal ewes, Mike Hyder, Research Officer, Department of Agriculture and Food, Western Australia

5. National Livestock Identification System (NLIS) for sheep and goats - what is the NLIS database? Leigh Sonnermann, …

Exogenous Administration Of Lipids To Steers Alters Aspects Of The Innate Immune Response To Endotoxin Challenge, Nicole C. Burdick Sanchez, Jeffery A. Carroll, Janet R. Donaldson, Joe O. Buntyn, Ty B. Schmidt

Department of Animal Science: Faculty Publications

This study examined the effects of increasing energy availability from both dextrose and lipid treatments on the proinflammatory response to LPS in Holstein steers. Steers were randomly assigned to one of three groups: saline at 0.5 ml/ kg body weight (Control) or 50% dextrose [0.5 ml/kg body weight (Dextrose) to mimic calm cattle’s response to LPS] administered immediately prior to LPS (0.5 mg/kg body weight at 0 h) or continuous lipid emulsion infusion from –1 to 6 h [Intralipid 20% (Baxter, Deerfield, IL USA); 0.5 ml/kg/hr (Lipid) to mimic temperamental cattle]. Concentrations of non-esterified fatty acids (NEFA) were greater in …

Mesh Ora Framework: R/Bioconductor Packages To Support Mesh Over-Representation Analysis, Koki Tsuyuzaki, Gota Morota, Manabu Ishii, Takeru Nakazato, Satoru Miyazaki, Itoshi Nikaido

Department of Animal Science: Faculty Publications

Background: In genome-wide studies, over-representation analysis (ORA) against a set of genes is an essential step for biological interpretation. Many gene annotation resources and software platforms for ORA have been proposed. Recently, Medical Subject Headings (MeSH) terms, which are annotations of PubMed documents, have been used for ORA. MeSH enables the extraction of broader meaning from the gene lists and is expected to become an exhaustive annotation resource for ORA. However, the existing MeSH ORA software platforms are still not sufficient for several reasons.

Results: In this work, we developed an original MeSH ORA framework composed of six types of …

A Cooperative Study On The Standardized Total-Tract Digestible Phosphorus Requirement Of Twenty-Kilogram Pigs, O. Adeola, M. J. Azain, S. D. Carter, T. D. Crenshaw, M. J. Estienne, B. J. Kerr, M. D. Lindemann, C. V. Maxwell, P. S. Miller, M. C. Shannon, E. Van Heugten

Department of Animal Science: Faculty Publications

A cooperative study comprising growth performance, bone mineralization, and nutrient balance experiments was conducted at 11 stations to determine the standardized total-tract digestible (STTD) P requirement of 20-kg pigs using broken-line regression analysis. Monocalcium phosphate and limestone were added to a corn–soybean meal–based diet at the expense of cornstarch to establish 6 concentrations of STTD P from 1.54 to 5.15 g/kg in increments of 0.62 g/kg at a constant Ca:total P of 1.52:1.0. Diets were fed to 936 pigs (average initial BW of 19 kg) in 240 pens for 20 replicate pens of barrows and 20 replicate pens of gilts …

Yield And Forage Value Of A Dual-Purpose Bmr-12 Sorghum Hybrid, Melinda K. Yerka, Andrea K. Pederson, J. J. Toy, Galen E. Erickson, Jeffrey F. Pedersen, Rob B. Mitchell

Department of Animal Science: Faculty Publications

Grain sorghum [Sorghum bicolor (L.) Moench] is an important crop for rainfed production systems with 2.7 million ha grown in the United States in 2013. The brown-midrib (bmr) mutations, especially bmr-12, have resulted in low stover lignin and high fiber digestibility without reducing grain yield in some sorghum lines. However, the effect of the bmr trait on beef cattle (Bos taurus) performance when grazing crop residue is unknown. Our objectives were to validate previous small-plot results reporting no grain yield difference between near-isogenic bmr-12 (BMR) and wild-type control (CON) A Wheatland × R

Tx430 …

Cattle With Increased Severity Of Bovine Respiratory Disease Complex Exhibit Decreased Capacity To Protect Against Histone Cytotoxicity, J. A. Matera, B. K. Krehbiel, J. A. Hernandez Gifford, D. L. Step, C. R. Krehbiel, C. A. Gifford

Department of Animal Science: Faculty Publications

Bovine respiratory disease complex (BRDC) is the leading cause of morbidity and mortality in feedlot cattle. Significant inflammation and lesions are often observed in lungs of infected cattle. During acute inflammatory responses, histones contribute to mortality in rodents and humans and serum proteins can protect against histone-induced cytotoxicity. We hypothesized that cattle experiencing chronic or fatal cases of BRDC have reduced ability to protect against cytotoxic effects of histones. Serum samples were collected from 66 bull calves at the time of normal feedlot processing procedures. Animals were retrospectively assigned to groups consisting of calves never treated for BRDC (control [CONT]; …