Animal Sciences Commons^™

Universal Dna Methylation Age Across Mammalian Tissues, A. T. Lu, Jessica Lynn Petersen, Steve Horvath, Et Al.

Department of Animal Science: Faculty Publications

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, …

Genetic Parameters For Heat And Salinity Stress Tolerance In Northern Gulf Of Mexico Eastern Oyster, Crassostrea Virginica, Paul Mcdonald

Master's Theses

Summer mortalities in Gulf of Mexico eastern oysters have been linked to excessively high temperatures, and chronic exposure to low salinity. In this study, the feasibility of improving tolerance to these two stresses by selection was evaluated in common garden experiments employing a pool of 160 families. Heat stress tolerance was evaluated in seed (3.5 months) and adults (14 months) by applying a sustained temperature of 38-39 °C until all oysters expired. Low salinity challenges on juveniles (9 months) and adults (15 months) applied a salinity of 2.5 psu. Survival duration of individual oysters during challenges was recorded and tissue …

Multispecies Genomic Sex Identification Using Ddx3 Gene Polymorphisms, Jessica Felts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

PCR sex determination assays must be reliable and cost effective due to the frequent and integral use of these assays in biological research and the animal production industry. Thus, the design of proof of a primer pair with a built-in control is warranted to not only bypass the extra cost of a multiplex reaction, but also to prevent anomalous results that have been documented with other primer pairs.

The objective of this study was to design primer pairs with built in PCR amplification control to identify sex in Equus caballus (domestic horse), Homo sapiens (humans), Macaca mulatta (rhesus macaque), and …

Combining Host And Rumen Metagenome Profiling For Selection In Sheep: Prediction Of Methane, Feed Efficiency, Production, And Health Traits, Melanie K. Hess, Larissa Zetouni, Andrew S. Hess, Juliana Budel, Ken G. Dodds, Hannah M. Henry, Rudiger Brauning, Alan F. Mcculloch, Sharon M. Hickey, Patricia L. Johnson, Sara Elmes, Janine Wing, Brooke Bryson, Kevin Knowler, Dianne Hyndman, Hayley Baird, Kathryn M. Mcrae, Arjan Jonker, Peter H. Janssen, John C. Mcewan, Suzanne J. Rowe

Department of Animal Science: Faculty Publications

Background Rumen microbes break down complex dietary carbohydrates into energy sources for the host and are increasingly shown to be a key aspect of animal performance. Host genotypes can be combined with microbial DNA sequencing to predict performance traits or traits related to environmental impact, such as enteric methane emissions. Metagenome profiles were generated from 3139 rumen samples, collected from 1200 dual purpose ewes, using restriction enzyme-reduced representation sequencing (RE-RRS). Phenotypes were available for methane (CH4) and carbon dioxide (CO2) emissions, the ratio of CH4 to CH4 plus CO2 (CH4Ratio), feed efficiency (residual feed intake: RFI), liveweight at the time …

Effects Of Feeding A Vitamin And Mineral Supplement To Cow-Calf Pairs Grazing Native Range, Jennifer L. Hurlbert, Friederike Baumgaertner, Kacie L. Mccathy, Timothy Long, Cody Wieland, Kevin K. Sedivec, Carl R. Dahlen

Department of Animal Science: Faculty Publications

Our objectives were to evaluate the impacts of providing vitamin and mineral (VTM) supplements to cow-calf pairs during the summer grazing period on cow and calf performance and liver concentrations of minerals. During a two-year period, 727 crossbred cows and their calves (initial cow BW = 601.7 ± 48.1 kg; calf BW = 87.8 ± 5.0 kg; n = 381 in year 1, n = 346 in year 2) from the Central Grasslands Research Extension Center (Streeter, N.D.) were blocked by parity (young [parity 1 to 3], and old [parity 4+]) and randomly assigned to pastures at the beginning …

Genotype By Environment Interaction And Heteroscedasticity Influence The Expression Of Parasite Resistance In Katahdin Sheep, Brian C. Arisman, Joan M. Burke, James L. M. Morgan, Ronald M. Lewis

Department of Animal Science: Faculty Publications

Increasingly, sheep producers are choosing breeds that express resistance to gastrointestinal parasites due to reduced efficacy of anthelminthic drugs. One such breed is Katahdin. Katahdins are raised in various climates and management systems in the United States, which can be combined into eco-management clusters to describe production environments more holistically. The objectives of this study were to determine if genotype by environment interaction (G × E) and heteroscedasticity existed across these eco-management clusters for traits indicative of parasite resistance. Body weights (BW), FAMACHA scores (FAM), and fecal egg counts (FEC) were collected at around 90 d in 3,527 Katahdin lambs …

Estimating Body Weight And Body Condition Score Of Mature Beef Cows Using Depth Images, Yijie Xiong, Isabella C.F.S. Condotta, J. A. Musgrave, Tami M. Brown-Bandl, J. Travis Mulliniks

Department of Animal Science: Faculty Publications

Obtaining accurate body weight (BW) is crucial for management decisions yet can be a challenge for cow–calf producers. Fast-evolving technologies such as depth sensing have been identified as low-cost sensors for agricultural applications but have not been widely validated for U.S. beef cattle. This study aimed to (1) estimate the body volume of mature beef cows from depth images, (2) quantify BW and metabolic weight (MBW) from image-projected body volume, and (3) classify body condition scores (BCS) from image-obtained measurements using a machine-learning-based approach. Fifty-eight crossbred cows with a mean BW of 410.0 ± 60.3 kg and were between 4 …

An Evolutionary Comparative Study Of Congenital Stationary Night Blindness-Associated Trpm1 Genetic Variants Of Uncertain Significance In Horses And Humans Utilizing Caenorhabditis Elegans, Gabrielle Davis

Theses

Congenital stationary night blindness (CSNB) is a heterogeneous collection of genetic diseases affecting the eyes and vision in horses and humans. Current research has implicated several genetic mutations impacting different genes involved in phototransduction and signal transmission, including TRPM1. In horses, genetic mutations in TRPM1 also result in a leopard spotting pattern or leopard complex. The goal of this study is to examine the potential impact of CSNB associated TRPM1 missense variants of uncertain significance (VUS). Previous research in Caenorhabditis elegans have revealed an orthologous TRPM1 gene known as gon-2 that allows for comparative studies. The evolutionary relationship of …

Characterization Of Antimicrobial Properties Of Excrement And Functional Microbiome Of Black Vultures (Coragyps Atratus), Bridgette Gray

Theses

Black vultures, Coragyps atratus, are obligate scavenging birds that consume and dispose of decaying carcasses and carrion. They fulfill a key ecological niche in the environments in which they live. It has been observed that these vultures sometimes excrete bodily waste onto their legs. This adaptive behavior could help aid them in controlling bacteria and other microbes they encounter while stepping into a carcass to eat. This study directly examined the antimicrobial properties of the excrement of black vultures across various bacterial species utilizing a zone of inhibition test and a nematode species utilizing a survival assay. The black vulture …

Mid-Gestation Maternofetal Inflammation Impacts Growth, Skeletal Muscle Glucose Metabolism, And Inflammatory Tone In The Ovine Fetus During Late Gestation, Zena Mariah Hicks

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

Our 1^st and 2^nd studies assessed the impact of mid-gestation maternofetal inflammation on growth, skeletal muscle glucose metabolism, and inflammatory tone in the late gestation ovine fetus. The objective was to determine if inducing maternofetal inflammation during peak placental growth would lead to more profound IUGR characteristics in the fetus. MI-IUGR fetuses exhibited reduced body and skeletal muscle weights and hallmark asymmetric growth at late gestations. Fetuses had higher baseline glucose:insulin ratios and reduced glucose-stimulated insulin secretion. Moreover, hindlimb glucose oxidation was impaired independent of glucose uptake. Skeletal muscle specific glucose uptake and oxidation was reduced in MI-IUGR …

Influence Of Maternal Dietary Protein Precursor On Reproductive Endocrinology Of Neonatal Bovine Offspring, Jennifer F. Thorson, Ligia D. Prezotto

Department of Animal Science: Faculty Publications

Bovine oogenesis and follicular maturation are initiated during in utero development, a process that is stringently orchestrated by the endocrine milieu. Of paramount importance are the three major biologically active estrogens: estron, estradiol, and estriol that are involved in the development and maintenance of germ cells. Previous work using the current model have revealed that maternal urea (protein precursor) supplementation reduces the ovarian follicular reserve without compromising the number of secondary and tertiary follicles. Therefore, we did not anticipate an influence of dietary treatment on biologically active estrogens. However, as the ovarian reserve is positively associated with circulating concentrations of …

Mineral Composition Of Serially Slaughtered Holstein Steers Supplemented With Zilpaterol Hydrochloride, Andrea K. Watson, Trent J. Mcevers, Lee-Anne J. Walter, Nathan D. May, Jacob A. Reed, J. C. Macdonald, Galen E. Erickson, N. Andy Cole, Johnjohn P. Hutcheson, Ty E. Lawrence

Department of Animal Science: Faculty Publications

Calf-fed Holstein steers (n = 115; 449 ± 20 kg) were utilized in a serial harvest experiment. A baseline group of five steers was harvested after 226 d on feed (DOF), which was designated day 0. The remaining cattle were assigned randomly to 11 harvest groups, with slaughter every 28 d. Cattle were either not (CON) or were fed zilpaterol hydrochloride for 20 d followed by a 3 d withdrawal (ZH). There were five steers per treatment in each slaughter group ranging from days 28 to 308. Whole carcasses were divided into lean, …

Genetic Considerations For The Conservation Of The Red Junglefowl, Courtney Lee Mcpheron

University Honors Theses

The undomesticated wild populations of our domestic species deserve heightened consideration when it comes to their conservation. Not only do they carry significant socio-cultural and economic roles, but they offer an exceptionally unique case study for population genetics. The red junglefowl (Gallus gallus) of southern and south-eastern Asia is considered to be the living ancestor and progenitor of the domestic chicken. This literature review examines how published research has evaluated its genetic relationship with the chicken and implications for its conservation. A special emphasis is given to the threat of genetic introgression with domestic and feral chicken populations …

Basic Fibroblast Growth Factor Induces Proliferation And Collagen Production By Fibroblasts Derived From The Bovine Corpus Luteum, Corrine F. Monaco, Michele R. Plewes, Emilia Przygrodzka, Jitu W. George, Fang Qiu, Peng Xiao, Jennifer R. Wood, Andrea S. Cupp, John S. Davis

Department of Animal Science: Faculty Publications

Cyclic regression of the ovarian corpus luteum, the endocrine gland responsible for progesterone production, involves rapid matrix remodeling. Despite fibroblasts in other systems being known for producing and maintaining extracellular matrix, little is known about fibroblasts in the functional or regressing corpus luteum. Vast transcriptomic changes occur in the regressing corpus luteum, among which are reduced levels of vascular endothelial growth factor A (VEGFA) and increased expression of fibroblast growth factor 2 (FGF2) after 4 and 12 h of induced regression, when progesterone is declining and the microvasculature is destabilizing. We hypothesized that FGF2 activates luteal …

Effect Of Vitamin C And Probiotics On Broilers Performance And Claudin-2 (Cldn-2) Expression Under Heat Stress [Research Note], Mohammad Chamani, Mohammad Chamani, Farhad Foroudi, Ali Asghar Sadeghi, Mehdi Aminafshar

The Philippine Agricultural Scientist

This study was conducted to investigate the effect of vitamin C and probiotic which consists of five species of beneficial bacteria and two species of fungi on performance, blood parameters, and intestinal CLDN-2 gene expression of broilers during heat stress (HS). A total of 400 broilers were randomly divided into five groups, each of which received a different treatment. The first group was considered a negative control and did not experience any HS (C^-); the second group was considered a positive control (C⁺) and was exposed to HS; the third group received only vitamin C (250 …

Integrative Analyses Of Genomic And Metabolomic Data Reveal Molecular Mechanisms Associated With Uterine Disease Traits In Transitioning Dairy Cattle, Leanna C. Sanchez, Mohammed Abo-Ismail, Daniel Peterson, Fernando Campos-Chillon

Master's Theses

The metritis complex (MC), characterizing post-partum uterine diseases in dairy cattle has negative implications on animal welfare, production efficiency, and the economic stability of the dairy industry. The studies in this thesis aimed to investigate the genetic architecture of the metritis complex and identify genomic regions and metabolites associated with the development of MC. Thereby enhancing our understanding of the biological pathways and molecular mechanisms involved in the pathophysiology of MC during the transition period in Jersey and Holstein dairy cattle.

Chapter 2 sheds light on the previous work done on MC. The goals of this review were to (1) …

Ethical Issues And Standards Of Responsible Research Conduct And Monitoring In An Adventist Institution Of Higher Learning - The Babcock Experience, Kayode O. Ogunwenmo, Godswill N. Anyasor, Grace O. Tayo

Adventist Human-Subject Researchers Association

Ethical issues and standards of responsible research conduct involving human participants are important considerations in any institution of higher learning and in particular Adventist institutions. Research conduct and ethics are reviewed and approved before they begin by the Babcock University Health Research Ethics Committee (BUHREC)

Impact Of Cattle Grazing Corn Residue In Spring On Soil And Subsequent Soybean Yield, Morgan T. Grabau, J. C. Macdonald, Zach E. Carlson, M. E. Drewnoski

Department of Animal Science: Faculty Publications

The effects of spring corn (Zea mays) residue grazing and stocking density on soil physical properties and subsequent soybean (Glycine max) yield were evaluated in an experiment with three treatments: no grazing (NG), normal stocking density (NSD), and high stocking density (HSD). The study was conducted over 2 years with four replicates per treatment each year. Steers (277 ± 4.4 kg) were stocked at 7.5 steers/ha for NSD with a target grazing of 45 days starting in mid- February, and 22.5 steers/ha for HSD with a target grazing of 15 days in mid-March, such that the …

Impact Of Shade In Beef Feedyards On Performance, Ear Temperature, And Heat Stress Measures, Thomas M. Winders, Brett A. Melton, Boyd M. Boyd, Casey N. Macken, J. C. Macdonald, Galen E. Erickson

Department of Animal Science: Faculty Publications

A 2-yr study (year 1: March to September 2017; year 2: February to August 2018) was conducted using crossbred steers (year 1: n = 1677; initial body weight [BW] = 372 kg, SD = 47; year 2: n = 1713; initial BW = 379 kg, SD = 10) in a commercial feedyard study in Eastern NE to determine the effects of shade on cattle performance, ear temperature, and cattle activity. Two treatments were evaluated using a randomized complete block design (n = 5 blocks based on arrival). Treatments were assigned randomly to pens and consisted of five pens without …

Prostaglandin F2Α Regulates Mitochondrial Dynamics And Mitophagy In The Bovine Corpus Luteum, Michele R. Plewes, Emilia Przygrodzka, Corrine F. Monaco, Alexandria P. Snider, Jessica Jessica Keane, Patrick D. Burns, Jennifer R. Wood, Andrea S. Cupp, John S. Davis

Department of Animal Science: Faculty Publications

Prostaglandins are arachidonic acid-derived lipid mediators involved in numerous physiological and pathological processes. PGF2α analogues are therapeutically used for regulating mammalian reproductive cycles and blood pressure, inducing term labor, and treating ocular disorders. PGF2α exerts effects via activation of calcium and PKC signaling, however, little is known about the cellular events imposed by PGF2α signaling. Here, we explored the early effects of PGF2α on mitochondrial dynamics and mitophagy in the bovine corpus luteum employing relevant and well characterized in vivo and in vitro approaches. We identified PKC/ERK and AMPK as critical protein kinases essential for activation of mitochondrial fission proteins, …

Evolution And Epidemiology Of Channel Catfish Virus (Ccv), Arun Venugopalan

Theses and Dissertations

Channel catfish virus disease (CCVD) is the principal viral disease in the United States catfish industry. The CCVD is caused by channel catfish virus (CCV), with mortality reaching up to 100% in fingerlings. CCV is assigned taxonomically to the family Alloherpesviridae, genus Ictalurivirus, species Ictalurid herpesvirus 1 (IcHV-1). To date, virulence, immunogenicity, and genome plasticity of the CCV field isolates have not been investigated. Three genotypes of CCV (IcHV-1A, IcHV-1B, and BCAHV) were identified using restriction fragment length polymorphism (RFLP) analysis. Virulence assessment of three representative isolates of RFLP groups suggests that IcHV-1B (pooled survival [mean ± SE]: 58.3% ± …

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works

Utilizing NuTrack To Access The Activity Levels In Pigs With Varying Degrees Of Genetic Potential For Growth And Feed Intake, Dalton Obermier, Melanie Trenahile-Grannemann, Ty B. Schmidt, Tom Rathje, Benny Mote

Department of Animal Science: Faculty Publications

Feed cost accounts for over two-thirds of the variable cost of production. In order to reduce feed costs without sacrificing production numbers, feed efficiency must be improved. Calorie expenditure has been difficult to quantify in the past but is understood to impact residual feed intake (RFI) greatly. The objective of this work was to utilize an advanced computer vision system to evaluate activity levels across sex and sire groups with different expected breeding value combinations for growth and feed intake. A total of 199 pigs from four different sire groups (DNA Genetics Line 600) High Feed Intake/High Growth (HIHG), Low …

Appearance Of Choline Metabolites In Plasma And Milk When Choline Is Infused Into The Abomasum With Or Without Methionine, C. J.R. Jenkins, Paul J. Kononoff

Department of Animal Science: Faculty Publications

Four lactating, ruminally cannulated Jersey cows, (mean ± standard deviation) 264 ± 54.2 d in milk and 484 ± 24.1 kg of body weight, were arranged in a 4 × 4 Latin square design to measure the effects of abomasal infusion of choline chloride with or without dl-Met on milk and plasma choline metabolites and plasma AA in cows fed a Met-deficient diet. Cows were randomly assigned to 1 of 4 experimental treatments: (1) control; no supplemental Met or choline (CON), (2) 13 g/d of choline ion delivered via abomasal infusion (CHO), (3) 13 g/d of Met delivered via abomasal …

Urbanization Affects Web Abundance And Aggregation Of A Funnel‑Weaving Spider, Agelenopsis Pennsylvanica (Agelenidae), Brandi J. Pessman, Madison Hays, Earl Agpawa, Eileen Hebets

Eileen Hebets Publications

Animals distribute themselves within habitats based on a variety of environmental conditions, including those impacted by urbanization. Suspected global declines in urban arthropod biodiversity have required that we examine how urban conditions affect the distribution of this ecologically important group. Throughout North America, funnel-weaving spiders (Agelenidae) are prevalent across urban habitats and actively choose sites to build webs. We compared Agelenopsis pennsylvanica abundance and distribution between two distinct urban habitats: an urban center (university campus) and an urban forest (city park). These urban habitats differed significantly in features like plant diversity and proximity to roads and highways. We searched along …

Molar Macrowear As A Proxy For Age In A Captive Sample Of Papio Hamadryas, Lauren Conrad

Biological Sciences Undergraduate Honors Theses

This study is methods-focused, centering around molar crown macrowear and its performance as a proxy for age in a sample of pedigreed, non-human primates. It analyzes the correlation between age-structured variables and molar wear among both males and females in a captive group of baboons. Here, I examined whether wear is significantly correlated with age-related variables (i.e., generations/cohorts) and whether the structure of the “age” dataset differed across wear categories. Because chronological age is unknown, I used documented pedigrees and parent-offspring relationships to group individuals into possible generations. I then used dental development charts to group individuals into cohorts based …

Dataset Of Rna-Seq Transcriptome Of The Fetal Liver At Day 83 Of Gestation Associated With Periconceptual Maternal Nutrition In Beef Heifers, Wellison J.S. Diniz, Alison K. Ward, Kacie L. Mccathy, Cierrah J. Kassetas, Friederike Baumgaertner, Lawrence P. Reynolds, Pawel P. Borowicz, Kevin K. Sedivec, James D. Kirsch, Sheri T. Dorsam, Tammi L. Neville, J. Chris Forcherio, Ronald Scott, Joel S. Caton, Carl R. Dahlen

Department of Animal Science: Faculty Publications

Herein, we present a dataset based on the RNA-Seq analysis of liver tissue from bovine female fetuses at day 83 of gestation. The findings were reported in the main article, “Periconceptual maternal nutrition affects fetal liver programming of energy- and lipid-related genes”[1] . These data were generated to investigate the effects of periconceptual maternal vitamin and mineral supplementation and rates of body weight gain on the transcript abundance of genes associated with fetal hepatic metabolism and function. To this end, crossbred Angus beef heifers ( n = 35) were randomly assigned to 1 of 4 treatments in a 2 × …

Influence Of Ambient Water Coloration On Habitat And Conspecific Choice In The Female Lake Malawi Cichlid, Metriaclima Zebra, Noori Choi, Nicolas Mathevon, Eileen A. Hebets, Marilyn Beauchaud

Eileen Hebets Publications

Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments. These sensory system adaptations are hypothesized to have influenced the evolution of the diverse male nuptial coloration. In rock-dwelling Lake Malawi mbuna cichlids, however, the extent to which ambient light environments influence female sensory systems and potentially associated male nuptial coloration remains unknown. Yet, the ubiquitous blue flank coloration and UV reflection of male mbuna cichlids suggest the potential impacts of the blue-shifted ambient light environment on these cichlid’s visual perception and male nuptial coloration in the shallow water …

Dataset Of Rna-Seq Transcriptome Of The Fetal Liver At Day 83 Of Gestation Associated With Periconceptual Maternal Nutrition In Beef Heifers, Wellison J.S. Diniz, Alison K. Ward, Kacie L. Mccathy, Cierrah J. Kassetas, Friederike Baumgaertner, Lawrence P. Reynolds, Pawel P. Borowicz, Kevin K. Sedivec, James D. Kirsch, Sheri T. Dorsam, Tammi L. Neville, J. Chris Forcherio, Ronald Scott, Joel S. Caton, Carl R. Dahlen

Department of Animal Science: Faculty Publications

Herein, we present a dataset based on the RNA-Seq analysis of liver tissue from bovine female fetuses at day 83 of gestation. The findings were reported in the main article, “Periconceptual maternal nutrition affects fetal liver programming of energy- and lipid-related genes”[1] . These data were generated to investigate the effects of periconceptual maternal vitamin and mineral supplementation and rates of body weight gain on the transcript abundance of genes associated with fetal hepatic metabolism and function. To this end, crossbred Angus beef heifers ( n = 35) were randomly assigned to 1 of 4 treatments in a 2 ×2 …

Evaluating Draft Epa Emissions Models For Laying Hen Facilities, Yijie Xiong, Guoming Li, Brett C. Ramirez, Robert T. Burns, Richard S. Gates

Department of Animal Science: Faculty Publications

In August 2021, the U.S. Environmental Protection Agency (EPA) released draft models to estimate daily NH₃, H₂S, PM₁₀, PM_2.5, and TSP emissions from egg-layer houses (high-rise and manure-belt) and manure storage using inputs of daily mean ambient temperature, relative humidity (RH), and hen inventory. These models were developed from refined datasets generated by the National Air Emissions Monitoring Study fieldwork completed in 2009. Notably, they do not include data for cage-free housing. Currently, 66% of U.S. laying hens are housed in cages; thus, these models, if adopted, will have a substantial impact …