Animal Sciences Commons^™

Variants Within Genes Edil3 And Adgrb3 Are Associated With Divergent Fecal Egg Counts In Katahdin Sheep At Weaning, Gabrielle M. Becker, Joan M. Burke, Ronald M. Lewis, James E. Miller, James L.M. Morgan, Benjamin D. Rosen, Curtis P. Van Tassell, David R. Notter, Brenda M. Murdoch

Department of Animal Science: Faculty Publications

Gastrointestinal nematodes (GIN) pose a severe threat to sheep production worldwide. Anthelmintic drug resistance coupled with growing concern regarding potential environmental effects of drug use have demonstrated the necessity of implementing other methods of GIN control. The aim of this study was to test for genetic variants associated with resistance or susceptibility to GIN in Katahdin sheep to improve the current understanding of the genetic mechanisms responsible for host response to GIN. Linear regression and casecontrol genome-wide association studies were conducted with high-density genotype data and cube-root transformed weaning fecal egg counts (tFEC) of 583 Katahdin sheep. The casecontrol GWAS …

Genomic Analysis Of Igg Antibody Response To Common Pathogens In Commercial Sows In Health-Challenged Herds, Leticia P. Sanglard, Piggen Canada, Benny E. Mote, Philip Willson, John C.S. Harding, Graham S. Plastow, Jack C.M. Dekkers, Nick V.L. Serão

Department of Animal Science: Faculty Publications

Losses due to infectious diseases are one of the main factors affecting productivity in the swine industry, motivating the investigation of disease resilience-related traits for genetic selection. However, these traits are not expected to be expressed in the nucleus herds, where selection is performed. One alternative is to use information from the commercial level to identify and select nucleus animals genetically superior for coping with pathogen challenges. In this study, we analyzed the genetic basis of antibody (Ab) response to common infectious pathogens in health-challenged commercial swine herds as potential indicator traits for disease resilience, including Ab response to influenza …

Genome-Wide Association Study To Identify Genetic Loci Associated With Gastrointestinal Nematode Resistance In Katahdin Sheep, G. M. Becker, K. M. Davenport, Joan M. Burke, Ronald M. Lewis, J. E. Miller, J. L.M. Morgan, D. R. Notter, B. M. Murdoch

Department of Animal Science: Faculty Publications

Resistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood. Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia. Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible sheep. A GWAS was conducted to identify possible genetic loci associated with resistance to Haemonchus contortus in Katahdin sheep. Forty animals were …

Including Phenotypic Causal Networks In Genome-Wide Association Studies Using Mixed Effects Structural Equation Models, Mehdi Momen, Ahmad Ayatollahi Mehrgardi, Mahmoud Amiri Roudbar, Andreas Kranis, Renan Mercuri Pinto, Bruno D. Valente, Gota Morota, Guilherme J.M. Rosa, Daniel Gianola

Department of Animal Science: Faculty Publications

Background: Phenotypic networks describing putative causal relationship among multiple phenotypes can be used to infer single-nucleotide polymorphism (SNP) effects in genome-wide association studies (GWAS). In GWAS with multiple phenotypes, reconstructing underlying causal structures among traits and SNPs using a single statistical framework is essential for understanding the entirety of genotype-phenotype maps. A structural equation model (SEM) can be used for such purpose.

Methods: We applied SEM to GWAS (SEM-GWAS) in chickens, taking into account putative causal relationships among body weight (BW), breast meat (BW), hen-house production (HHP), and SNPs. We assessed the performance of SEM-GWAS by comparing the model results …

Genome-Wide Association Study For Feed Efficiency And Growth Traits In U.S. Beef Cattle, Christopher M. Seabury, David L. Oldeschulte, Mahdi Saatchi, Jonathan E. Beever, Jared E. Decker, Yvette A. Halley, Eric K. Bhattarai, Maral Molael, Harvey Freetly, Stephanie L. Hansen, Helen Yampara-Iquise, Kristen A. Johnson, Monty S. Kerley, Jaewoo Kim, Daniel D. Loy, Elisa Marques, Holly L. Neibergs, Robert D. Schnabel, Daniel W. Shike, Matthew L. Spangler, Bob Weaber, D. J. Garrick, Jeremy F. Taylor

Department of Animal Science: Faculty Publications

Background: Single nucleotide polymorphism (SNP) arrays for domestic cattle have catalyzed the identification of genetic markers associated with complex traits for inclusion in modern breeding and selection programs. Using actual and imputed Illumina 778K genotypes for 3887 U.S. beef cattle from 3 populations (Angus, Hereford, SimAngus), we performed genome-wide association analyses for feed efficiency and growth traits including average daily gain (ADG), dry matter intake (DMI), mid-test metabolic weight (MMWT), and residual feed intake (RFI), with marker-based heritability estimates produced for all traits and populations.

Results: Moderate and/or large-effect QTL were detected for all traits in all populations, as jointly …

Qtls Associated With Dry Matter Intake, Metabolic Mid-Test Weight, Growth And Feed Efficiency Have Little Overlap Across 4 Beef Cattle Studies, Mahdi Saatchi, Jonathan E. Beever, Jared E. Decker, Dan B. Faulkner, Harvey C. Freetly, Stephanie L. Hansen, Helen Yampara-Iquise, Kristen A. Johnson, Stephen D. Kachman, Monty S. Kerley, Jaewoo Kim, Daniel D. Loy, Elisa Marques, Holly L. Neibergs, E. John Pollak, Robert D. Schnabel, Christopher M. Seabury, Daniel W. Shike, W. M. Snelling, Matthew L. Spangler, Robert L. Weaber, D. J. Garrick, Jeremy F. Taylor

Department of Animal Science: Faculty Publications

Background: The identification of genetic markers associated with complex traits that are expensive to record such as feed intake or feed efficiency would allow these traits to be included in selection programs. To identify large-effect QTL, we performed a series of genome-wide association studies and functional analyses using 50 K and 770 K SNP genotypes scored in 5,133 animals from 4 independent beef cattle populations (Cycle VII, Angus, Hereford and Simmental × Angus) with phenotypes for average daily gain, dry matter intake, metabolic mid-test body weight and residual feed intake.

Results: A total of 5, 6, 11 and 10 significant …