Beef Science Commons^™

The Ovarian Follicle Of Ruminants: The Path From Conceptus To Adult, Jennifer L. Juengel, Robert A. Cushman, Joëlle Dupont, Stéphane Fabre, Richard G. Lea, Graeme B. Martin, Francesca Mossa, Janet L. Pitman, Christopher A. Price, Peter Smith

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

This review resulted from an international workshop and presents a consensus view of critical advances over the past decade in our understanding of follicle function in ruminants. The major concepts covered include: (1) the value of major genes; (2) the dynamics of fetal ovarian development and its sensitivity to nutritional and environmental influences; (3) the concept of an ovarian follicle reserve, aligned with the rise of anti-Müllerian hormone as a controller of ovarian processes; (4) renewed recognition of the diverse and important roles of theca cells; (5) the importance of follicular fluid as a microenvironment that determines oocyte quality; (6) …

Evolution Of The Sheep Industry And Genetic Research In The United States: Opportunities For Convergence In The Twenty-First Century, J. W. Thorne, B. M. Murdoch, B. A. Freking, R. R. Redden, Thomas W. Murphy, J. B. Taylor, Harvey D. Blackburn

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

The continuous development and application of technology for genetic improvement is a key element for advancing sheep production in the United States. The US sheep industry has contracted over time but appears to be at a juncture where a greater utilization of technology can facilitate industry expansion to new markets and address inefficiencies in traditional production practices. Significant transformations include the increased value of lamb in relation to wool, and a downtrend in large-scale operations but a simultaneous rise in small flocks. Additionally, popularity of hair breeds not requiring shearing has surged, particularly in semi-arid and subtropical US environments. A …

Influence Of Estradiol On Bovine Trophectoderm And Uterine Gene Transcripts Around Maternal Recognition Of Pregnancy, Emmalee J. Northrop-Albrecht, Jerica J.J. Rich, Robert A. Cushman, Runan Yao, Xijin Ge, George A. Perry

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

Embryo survival and pregnancy success is increased among animals that exhibit estrus prior to fixed time-artificial insemination, but there are no differences in conceptus survival to d16. The objective of this study was to determine effects of preovulatory estradiol on uterine transcriptomes, select trophectoderm (TE) transcripts, and uterine luminal fluid proteins. Beef cows/heifers were synchronized, artificially inseminated (d0), and grouped into either high (highE2) or low (lowE2) preovulatory estradiol. Uteri were flushed (d16); conceptuses and endometrial biopsies (n = 29) were collected. RNA sequencing was performed on endometrium. Real-time polymerase chain reaction (RT-PCR) was performed on TE (n = 21) …

Low-Oxygen Dry Aging Of Beef, Joseph A. Sonderman

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

The objective of this research project was to determine the effects of removing oxygen from the beef dry aging process. Boneless upper 2/3 Choice beef strip loins (n = 18) were randomly assigned to three aging treatments: wet aging, traditional (aerobic) dry aging, and low-oxygen dry aging. All treatments were aged for 41 days at 2 ± 1°C. The dry-aged treatments were held at 50% relative humidity (RH) with a fan speed of 2,200 revolutions per minute (RPM). Low-oxygen dry-aged samples were aged in chambers housed within an oxygen impermeable film bubble. After aging, yield was determined for the …

Complete Closed Genome Sequence Of The Extremely Heat- Resistant Strain Escherichia Coli Aw1.7, Manita Guragain, James L. Bono, Joseph M. Bosilevac

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

Escherichia coli isolate AW1.7 is an extremely heat-resistant bacterium and has been widely used as a reference strain in extreme heat resistance studies for almost a decade. Here, we report its complete closed genome sequence.

Using Genomics To Measure Phenomics: Repeatability Of Bull Prolificacy In Multiple-Bull Pastures, Gary L. Bennett, John W. Keele, Larry A. Kuehn, Warren M. Snelling, Robert A. Cushman, Tara G. Mcdaneld, Aaron M. Dickey, Darrell Light

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

Phenotypes are necessary for genomic evaluations and management. Sometimes genomics can be used to measure phenotypes when other methods are difficult or expensive. Prolificacy of bulls used in multiple-bull pastures for commercial beef production is an example. A retrospective study of 79 bulls aged 2 and older used 141 times in 4–5 pastures across 4 years was used to estimate repeatability from variance components. Traits available before each season’s use were tested for predictive ability. Sires were matched to calves using individual genotypes and evaluating exclusions. A lower-cost method of measuring prolificacy was simulated for five pastures using the bulls’ …

Production Performance Of Cows Raised With Different Postweaning Growth Patterns, Harvey C. Freetly, Robert A. Cushman, Gary L. Bennett

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

The period of heifer development is a relatively small fraction of a cow's life; however, her pattern of growth may have permanent effects on her productivity as a cow. We hypothesized that altering the growth pattern during the peri-pubertal period would increase life-time productivity across genetic types of Bos taurus cows. The objective was to determine the stayability, calf production, and weight of calf weaned across six calf crops. Heifers (n = 685) were placed on one of two developmental programs at 256 ± 1 d of age. Control heifers received a diet that provided 228 kcal ME·(body weight [BW], …

The Usda-Ars Ag100pest Initiative: High-Quality Genome Assemblies For Agricultural Pest Arthropod Research, Anna K. Childers, Scott M. Geib, Sheina B. Sim, Monica F. Poelchau, Brad S. Coates, Tyler J. Simmonds, Erin D. Scully, Timothy P. L. Smith, Christopher P. Childers, Renee L. Corpuz, Kevin Hackett, Brian Scheffler

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

The phylum Arthropoda includes species crucial for ecosystem stability, soil health, crop production, and others that present obstacles to crop and animal agriculture. The United States Department of Agriculture’s Agricultural Research Service initiated the Ag100Pest Initiative to generate reference genome assemblies of arthropods that are (or may become) pests to agricultural production and global food security. We describe the project goals, process, status, and future. The first three years of the project were focused on species selection, specimen collection, and the construction of lab and bioinformatics pipelines for the efficient production of assemblies at scale. Contig-level assemblies of 47 species …

Enhancement Of Dry-Aged Beef Quality By Dietary Supplementation Of High Levels Of Vitamin E, David Manuel Velazco Marroquin

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

Crossbred cattle (n = 150; 10/pen) were grain-finished with the dietary addition of 2,200 international units of vitamin E (α-tocopherol) per head per day for 100 days. One low-Choice carcass (n = 12) was selected, and strip loins were collected. Low Choice control carcasses (n = 12) were randomly selected from commercial, fed-cattle production to serve as controls. Strip loins were randomly assigned to wet or dry aging for 42 days. On day 42, control dry-aged and control wet-aged loins had the highest TBARS values and vitamin E wet and dry-aged loins had lower TBARS values ( …

Reference Transcriptomes Of Porcine Peripheral Immune Cells Created Through Bulk And Single-Cell Rna Sequencing, Juber Herrera-Uribe, Jayne E. Wiarda, Sathesh K. Sivasankaran, Lance Daharsh, Haibo Liu, Kristen A. Byrne, Timothy P. L. Smith, Joan K. Lunney, Crystal L. Loving, Christopher Tuggle

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

Pigs are a valuable human biomedical model and an important protein source supporting global food security. The transcriptomes of peripheral blood immune cells in pigs were defined at the bulk cell-type and single cell levels. First, eight cell types were isolated in bulk from peripheral blood mononuclear cells (PBMCs) by cell sorting, representing Myeloid, NK cells and specific populations of T and B-cells. Transcriptomes for each bulk population of cells were generated by RNA-seq with 10,974 expressed genes detected. Pairwise comparisons between cell types revealed specific expression, while enrichment analysis identified 1,885 to 3,591 significantly enriched genes across all 8 …

Effects Of Farrowing Stall Layout And Number Of Heat Lamps On Sow And Piglet Behavior, Suzanne Leonard, Hongwei Xin, Tami M. Brown-Bandl, Brett C. Ramirez, Anna K. Johnson, Somak Dutta, G.A. Rohrer

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

Farrowing stalls are used in the United States swine industry to reduce pre-weaning piglet mortality, enable efficient individual animal management, and decrease facility construction and operating costs. The quantity and quality of space provided for sows and piglets in farrowing stalls are important economic and welfare considerations. To further explore the impacts of farrowing stall space allocation, a large-scale field study was conducted to compare sow and piglet behavior when housed in three farrowing stall layouts (TSL – traditional stall layout, ECSL – expanded creep area stall layout, ESCSL – expanded sow and creep area stall layout) with either one …

Invited Review: Mineral Nutrition Considerations For Extensive Sheep Production Systems, W. C. Stewart, J. D. Scasta, J. B. Taylor, T. W. Murphy, A. A.M. Julian

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

Purpose: Our purpose is to discuss contemporary and pertinent considerations related to mineral-supplementation strategies for sheep grazing marginal rangelands in extensively managed production systems. Sources: Grey literature, peer-reviewed literature, and data (published and unpublished) from co-authors were used. Synthesis: Precision trace-mineral nutrition of sheep that are grazing extensive production systems requires a comprehensive understanding of the sheep and the grazing environment. Generally, extensive sheep production systems are found in remote geographical regions composed of marginal rangelands not suitable for cultivated crop farming or improved forages. Sheep production is subject to the accessibility and availability of grazable forage, which may vary …

Variants In The Mitochondrial Genome Sequence Of Rhyzopertha Dominica (Fabricius) (Coleoptera: Bostrycidae), Lindsey C. Perkin, Timothy P.L. Smith, Brenda Oppert

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

The lesser grain borer, Rhyzopertha dominica, is a coleopteran pest of stored grains and is mainly controlled by phosphine fumigation, but the increase in phosphine-resistant populations threatens efficacy. Some phosphine-resistant insects have reduced respiration, and thus studying the mitochondrial genome may provide additional information regarding resistance. Genomic DNA from an inbred laboratory strain of R. dominica was extracted and sequenced with both short (Illumina) and long (Pacific Biosciences) read technologies for whole genome sequence assembly and annotation. Short read sequences were assembled and annotated by open software to identify mitochondrial sequences, and the assembled sequence was manually annotated and verified …

Strain And Host-Cell Dependent Role Of Type-1 Fimbriae In The Adherence Phenotype Of Super-Shed Escherichia Coli O157:H7, Robab Katani, Indira T. Kudva, Sreenidhi Srinivasan, Judith B. Stasko, Megan Schilling, Lingling Li, Rebecca Cote, Chitrita Debroy, Terrance M. Arthur, Evgeni V. Sokurenko, Vivek Kapur

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

Super-shed (SS) Escherichia coli O157 (E. coli O157) demonstrate a strong, aggregative, locus of enterocyte effacement (LEE)-independent adherence phenotype on bovine recto-anal junction squamous epithelial (RSE) cells, and harbor polymorphisms in non-LEE-adherence-related loci, including in the type 1 fimbriae operon. To elucidate the role of type 1 fimbriae in strain- and host-specific adherence, we evaluated the entire Fim operon (FimB-H) and its adhesion (FimH) deletion mutants in four E. coli O157 strains, SS17, SS52, SS77 and EDL933, and evaluated the adherence phenotype in bovine RSE and human HEp-2 adherence assays. Consistent with the prevailing dogma that fimH expression is genetically …

Nebraska Cow–Calf Operations: Use Of Pricing Tools And Market Diversification Strategies To Manage Market Risk, Logan Kalkowski

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This thesis is divided into three chapters. The first chapter of this thesis investigates years of research and data collection from multiple agencies to find connections to reasoning for producers to choose marketing and diversification tools used in their operation.

The second chapter examines cow-calf marketing and risk management practices in Nebraska. Marketing and risk management behavior are examined by using the University of Nebraska-Lincoln Cow-calf survey data collected in 2016. The survey captures characteristics of operations and their use of marketing and risk management practices. While it is important to understand what operations are doing currently, it is also …

Relationships Among Intramammary Health, Udder And Teat Characteristics, And Productivity Of Extensively Managed Ewes, Ryan M. Knuth, Whitney C. Stewart, Joshua B. Taylor, Bledar Bisha, Carl J. Yeoman, Megan L. Van Emon, Thomas W. Murphy

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

Mastitis is an economically important disease and its subclinical state is difficult to diagnose, which makes mitigation more challenging. The objectives of this study were to screen clinically healthy ewes in order to 1) identify cultivable microbial species in milk, 2) evaluate somatic cell count (SCC) thresholds associated with intramammary infection, and 3) estimate relationships between udder and teat morphometric traits, SCC, and ewe productivity. Milk was collected from two flocks in early (<5 >d) and peak (30 to 45 d) lactation to quantify SCC (n = 530) and numerate cultivable microbial species by culture-based isolation followed by matrix-assisted laser …

Locus Of Heat Resistance (Lhr) In Meat-Borne Escherichia Coli: Screening And Genetic Characterization, Manita Guragain, Dayna M. Brichta-Harhay, James L. Bono, Joseph M. Bosilevac

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

Microbial resistance to processing treatments poses a food safety concern, as treatment tolerant pathogens can emerge. Occasional foodborne outbreaks caused by pathogenic Escherichia coli have led to human and economic losses. Therefore, this study screened for the extreme heat resistance (XHR) phenotype as well as one known genetic marker, the locus of heat resistance (LHR), in 4,123 E. coli isolates from diverse meat animals at different processing stages. The prevalences of XHR and LHR among the meat-borne E. coli were found to be 10.3% and 11.4%, respectively, with 19% agreement between the two. Finished meat products showed the highest LHR …

Characterization Of The Domestic Goat Γδ T Cell Receptor Gene Loci And Gene Usage, Alexandria Gillespie, Al Yirsaw, Karthick P. Gunasekaran, Timothy P. L. Smith, Derek M. Bickhart, Michael Turley, Timothy Connelley, Janice C. Telfer, Cynthia L. Baldwin

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

Goats and cattle diverged 30 million years ago but retain similarities in immune system genes. Here, the caprine T cell receptor (TCR) gene loci and transcription of its genes were examined and compared to cattle. We annotated the TCR loci using an improved genome assembly (ARS1) of a highly homozygous San Clemente goat. This assembly has already proven useful for describing other immune system genes including antibody and leucocyte receptors. Both the TCRγ (TRG) and TCRδ (TRD) loci were similarly organized in goats as in cattle and the gene sequences were highly conserved. However, the number of genes varied slightly …

Evaluation Of Condensed Algal Residue Solubles As An Ingredient In Cattle Finishing Diets And Its Effects On Digestibility And Fatty Acid Flow And A Comparison Of Single And Dual Implant Strategies In Finishing Heifers, John Calvin Gibbons

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

Two experiments, a performance study (Exp. 1) and digestion study (Exp. 2) were conducted to evaluate a novel liquid feed, condensed algal residue solubles (CARS), in feedlot diets. In Exp. 1 and Exp. 2, steers were fed three inclusions of CARS at 0%, 2.5%, 5%. There were quadratic responses for greater carcass adjusted final BW, ADG, G:F, HCW, 12^th rib fat, and yield grade. There was a linear increase in marbling score and a linear decrease in DMI and LM area as CARS increased. In Exp. 2, CARS did not affect intake or digestibility. Fatty acid flow at the …

Cytokine And Haptoglobin Profiles From Shipping Through Sickness And Recovery In Metaphylaxis- Or Un-Treated Cattle, Carol G. Chitko-Mckown, Gary L. Bennett, Larry A. Kuehn, Keith D. Dedonder, Michael D. Apley, Gregory P. Harhay, Michael L. Clawson, Aspen M. Workman, Bradley J. White, Robert L. Larson, Sarah F. Capik, Brian V. Lubbers

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

Fifty-six head of cattle, 28 animals with bovine respiratory disease complex (BRDC), and 28 healthy animals that were matched by treatment, sale barn of origin, day, and interactions among these variables, were identified from a population of 180 animals (60 each purchased at three sale barns located in Missouri, Tennessee, and Kentucky) enrolled in a study comparing animals receiving metaphylaxis to saline-treated controls. Cattle were transported to a feedlot in KS and assigned to treatment group. Blood samples were collected at Day 0 (at sale barn), Day 1, Day 9, and Day 28 (at KS feedlot), and transported to the …

Breed Differences In Placental Development During Late Gestation Between Chinese Meishan And White Crossbred Gilts In Response To Intrauterine Crowding, Jeremy R. Miles, Jeffrey L. Vallet

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

The objective of this study was to evaluate placental development during late gestation (day 100) between Chinese Meishan (CM; n = 7) and White crossbred (WC; n = 5) gilts following intrauterine crowding induced by unilaterally hysterectomy-ovariectomy. Gross placental morphology and areolae density as well as histological morphology (i.e., folded bilayer and placental stroma) were analyzed using computer-assisted morphometry for placentas of the smallest and largest fetuses within each litter. There was a breed by fetal size interaction (P < 0.01) for areolae density in which placentas for large CM fetuses had greater areolae density compared to small CM fetuses, but the density of areolae was greater for CM fetuses compared to WC fetuses, irrespective of fetal size. The width of the folded bilayer was greater (P < 0.01) in placentas for WC gilts compared to CM gilts, irrespective of fetal size. Placentas for small fetuses had greater (P < 0.01) folded bilayer width compared to large fetuses, irrespective of breed. The placental stromal width was greater (P < 0.01) in placentas for large fetuses compared to small, irrespective of breed. The difference between stromal width in placentas between divergent-sized littermates, however, was greater (P = 0.05) in WC gilts compared to CM gilts, indicating there was a limited response to intrauterine crowding in CM gilts. These results indicate there is an altered placental development during late gestation in CM compared to WC gilts, thus, there are likely different mechanisms for responding to intrauterine crowding between breeds.

A Reference Genome Assembly Of Simmental Cattle, Bos Taurus Taurus, Michael P. Heaton, Timothy P.L. Smith, Derek M. Bickhart, Brian L. Vander Ley, Larry A. Kuehn, Jonas Oppenheimer, Wade R. Shafer, Fred T. Schuetze, Brad Stroud, Jennifer C. Mcclure, Jennifer P. Barfield, Harvey D. Blackburn, Theodore S. Kalbfleisch, Kimberly M. Davenport, Kristen L. Kuhn, Richard E. Green, Beth Shapiro, Benjamin D. Rosen

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

Genomics research has relied principally on the establishment and curation of a reference genome for the species. However, it is increasingly recognized that a single reference genome cannot fully describe the extent of genetic variation within many widely distributed species. Pangenome representations are based on high-quality genome assemblies of multiple individuals and intended to represent the broadest possible diversity within a species. A Bovine Pangenome Consortium (BPC) has recently been established to begin assembling genomes from more than 600 recognized breeds of cattle, together with other related species to provide information on ancestral alleles and haplotypes. Previously reported de novo …

A Reference Genome Assembly Of American Bison, Bison Bison Bison, Jonas Oppenheimer, Benjamin D. Rosen, Michael P. Heaton, Brian L. Vander Ley, Wade R. Shafer, Fred T. Schuetze, Brad Stroud, Larry A. Kuehn, Jennifer C. Mcclure, Jennifer P. Barfield, Harvey D. Blackburn, Theodore S. Kalbfleisch, Derek M. Bickhart, Kimberly M. Davenport, Kristen L. Kuhn, Richard E. Green, Beth Shapiro, Timothy P.L. Smith

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

Bison are an icon of the American West and an ecologically, commercially, and culturally important species. Despite numbering in the hundreds of thousands today, conservation concerns remain for the species, including the impact on genetic diversity of a severe bottleneck around the turn of the 20th century and genetic introgression from domestic cattle. Genetic diversity and admixture are best evaluated at genome-wide scale, for which a high-quality reference is necessary. Here, we use trio binning of long reads from a bison-Simmental cattle (Bos taurus taurus) male F1 hybrid to sequence and assemble the genome of the American plains bison (Bison …

Evaluating Accuracy Of Dna Pool Construction Based On White Blood Cell Counts, Amy N. Abrams, T. G. Mcdaneld, John W. Keele, Carol G. Chitko-Mckown, Larry A. Kuehn, Michael G. Gonda

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

Pooling individual samples prior to DNA extraction can mitigate the cost of DNA extraction and genotyping; however, these methods need to accurately generate equal representation of individuals within pools. The objective of this study was to determine accuracy of pool construction of blood samples based on white blood cell counts compared to two common DNA quantification methods. Fifty individual bovine blood samples were collected, and then pooled with all individuals represented in each pool. Pools were constructed with the target of equal representation of each individual animal based on number of white blood cells, spectrophotometric readings, spectrofluorometric readings, and whole …

Rapid Estimation Of Salmonella Enterica Contamination Level In Ground Beef – Application Of The Time-To-Positivity Method Using A Combination Of Molecular Detection And Direct Plating, Dayna M. Harhay, Margaret D. Weinroth, James L. Bono, Gregory P. Harhay, Joseph M. Bosilevac

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

Little progress has been made in decreasing the incidence rate of salmonellosis in the US over the past decade. Mitigating the contribution of contaminated raw meat to the salmonellosis incidence rate requires rapid methods for quantifying Salmonella, so that highly contaminated products can be removed before entering the food chain. Here we evaluated the use of Time-to-Positivity (TTP) as a rapid, semi-quantitative approach for estimating Salmonella contamination levels in ground beef. Growth rates of 14 Salmonella strains (inoculated at log 1 to −2 CFU/g) were characterized in lean ground beef mTSB enrichments and time-to-detection was determined using culture and molecular …

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 …

An Environmental Assessment Of Cattle Manure And Urea Fertilizer Treatments For Corn Production In The Northern Great Plains, C. Alan Rotz, Senorpe Asem-Hiablie, Erin Cortus, Mindy J. Spiehs, Shafiqur Rahman, Anne Stoner

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

Nitrogen (N), phosphorus (P), and carbon (C) emissions from livestock systems have become important regional, national, and international concerns. Our objective was to use process-level simulation to explore differences among manure and inorganic fertilizer treatments in a corn production system used to feed finishing cattle in the Northern Great Plains region of the U.S. Our analysis included model assessment, simulation to compare treatments under recent climate, and comparisons using projected midcentury climate. The Integrated Farm System Model was evaluated in representing the performance and nutrient losses of corn production using cattle manure without bedding, manure with bedding, urea, and no …

Use Of Bedding Materials In Beef Bedded Manure Packs In Hot And Cool Ambient Temperatures: Effects On Ammonia, Hydrogen Sulfide, And Greenhouse Gas Emissions, Jeff P. Jaderborg, Mindy J. Spiehs, Bryan L. Woodbury, Alfredo Dicostanzo, David B. Parker

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

Throughout the Upper Midwest, producers have observed increased land and fertilizer prices, resulting in increased popularity of confinement feeding facilities such as mono-slope and hoop barns with bedded packs. Environmental and public pressure has been placed on the agriculture community to reduce ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gas (GHG) emissions from concentrated animal feeding operations (CAFOs). This study was conducted to determine the effects of bedding material (corn stover (CS), bean stover (BS), wheat straw (WS), or pine wood chips (PC)) and ambient temperature (15°C (COOL) or 30°C (HOT)) on NH3, CH4, CO2, N2O, and H2S flux in …

Evaluation Of Cd109, Pcp4 And Sema3d Genes For Their Association With Ovine Johne’S Disease In Turkish Sheep, Yalçın Yaman, Ramazan Aymaz, Murat Keleş, Veysel Bay, Ecem Hatipoğlu, Cüneyt Kaptan, Atilla Başkurt, Onur Yilmaz, Michael P. Heaton

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

Johne’s disease is a chronic, contagious, zoonotic disease that affects numerous species including livestock and sometimes humans. The disease is globally distributed in sheep populations and caused by Mycobacterium avium Subsp. paratuberculosis (MAP). A previous genome-wide association study identified single nucleotide polymorphism (SNP) markers associated with OJD serostatus in CD109, PCP4, and SEMA3D genes. Our aim was to evaluate the same markers for association with OJD seroprevalence in Turkish sheep in a retrospective matched case-control study. The serological status for OJD in 1801 sheep was determined for four native and four composite breeds from three research flocks. One hundred eleven …

Comparison Of Performance Of F1 Romanov Crossbred Ewes With Wool And Hair Breeds During Spring Lambing Under Intensive And Extensive Production Systems, Brad A. Freking, Thomas W. Murphy

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

The objective was to evaluate wool (Dorset and Rambouillet) and hair (Dorper, Katahdin, and White Dorper) breeds for their ability to complement Romanov germplasm in two distinct production systems by estimating direct sire and grandsire effects on lamb growth, survival, and ewe productivity traits. Rams of the five breeds (n = 75) were mated to Romanov ewes (n = 459) over a 3-yr period to produce five types of crossbred lambs (n = 2,739). Sire breed (P > 0.06) did not impact body weight or survival traits of the first-generation crossbred (F1) lambs. The productivity of retained crossbred ewes (n = …