Genetics and Genomics Commons^™

How The Leopard Hides Its Spots: Asip Mutations And Melanism In Wild Cats, Alexsandra Schneider, Victor A. David, Warren E. Johnson, Stephen J. O'Brien, Gregory S. Barsh, Marilyn Menotti-Raymond, Eduardo Eizirik

Biology Faculty Articles

The occurrence of melanism (darkening of the background coloration) is documented in 13 felid species, in some cases reaching high frequencies at the population level. Recent analyses have indicated that it arose multiple times in the Felidae, with three different species exhibiting unique mutations associated with this trait. The causative mutations in the remaining species have so far not been identified, precluding a broader assessment of the evolutionary dynamics of melanism in the Felidae. Among these, the leopard (Panthera pardus) is a particularly important target for research, given the iconic status of the ‘black panther’ and the extremely …

Molecular Surveillance Of Low Pathogenic Avianinfluenza Viruses In Wild Birds Across The United States:Inferences From The Hemagglutinin Gene, Antoinette J. Piaggio, Susan A. Shriner, Kaci Van Dalen, Alan B. Franklin, Theodore D. Anderson, Sergios-Orestis Kolokotronis

Alan B Franklin

A United States interagency avian influenza surveillance plan was initiated in 2006 for early detection of highly pathogenic avian influenza viruses (HPAIV) in wild birds. The plan included a variety of wild bird sampling strategies including the testing of fecal samples from aquatic areas throughout the United States from April 2006 through December 2007. Although HPAIV was not detected through this surveillance effort we were able to obtain 759 fecal samples that were positive for low pathogenic avian influenza virus (LPAIV). We used 136 DNA sequences obtained from these samples along with samples from a public influenza sequence database for …

Deglaciation Explains Bat Extinction In The Caribbean, Liliana M. Davalos, Amy L. Russell

Amy L. Russell

Intsormil- Centa’S New Bmr Sorghum Varieties Create A Surge In Dairy Production, René Clará Valencia

INTSORMIL Scientific Publications

Scientists from the INTSORMIL-CENTA project based at the National Center for Agricultural Technology and Forestry (CENTA) of El Salvador have worked for five years to develop varieties of sorghum for grain and forage that are highly nutritious to cattle. Using the gene bmr-12, received from Dr. Gebisa Ejeta of Purdue University, they combined commercial varieties CENTA S-2, S-3 CENTA, CENTA RCV and VG 146 and were able to form new varieties containing this same gene. The first generation created 76 new varieties.

Genetic Diversity Of Neotropical Myotis (Chiroptera: Vespertilionidae) With An Emphasis On South American Species, Roxanne J. Larsen, Michelle C. Knapp, Hugh H. Genoways, Faisal Ali Anwarali Khan, Peter A. Larsen, Don E. Wilson, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Background: Cryptic morphological variation in the Chiropteran genus Myotis limits the understanding of species boundaries and species richness within the genus. Several authors have suggested that it is likely there are unrecognized species-level lineages of Myotis in the Neotropics. This study provides an assessment of the diversity in New World Myotis by analyzing cytochrome-b gene variation from an expansive sample ranging throughout North, Central, and South America. We provide baseline genetic data for researchers investigating phylogeographic and phylogenetic patterns of Myotis in these regions, with an emphasis on South America.

Methodology and Principal Findings: Cytochrome-b sequences were generated and …

Mutations In Dmrt3 Affect Locomotion In Horses And Spinal Circuit Function In Mice, Lisa S. Andersson, Martin Larhammar, Fatima Memic, Hanna Wootz, Doreen Schwochow, Carl-Johan Rubin, Kalicharan Patra, Thorvaldur Arnason, Lisbeth Wellbring, Göran Hjälm, Freyja Imsland, Jessica Lynn Petersen, Molly E. Mccue, James R. Mickelson, Gus Cothran, Nadav Ahituv, Lars Roepstorff, Sofia Mikko, Anna Vallstedt, Gabriella Lindgren, Leif Andersson, Klas Kullander

Department of Animal Science: Faculty Publications

Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left–right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favorable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes …

A Genetic Survey Of English Sole Populations In The Salish Sea, Elizabeth S. Gutierrez, Gary A. Winans, Jon Baker, Amanda Cope

STAR Program Research Presentations

This summer I interned at the Northwest Fisheries Science Center in Seattle, WA and participated in NOAA’s Salish Sea Project. The Salish Sea Project’s goal is to identify genetically distinctive groups of species in the Salish Sea that may have unique evolutionary and/or adaptive backgrounds. These findings will allow NOAA to promote and monitor the natural production of species in the Salish Sea, to select representative populations for experimental work regarding pollution, ocean acidification and climate change, to contribute to managing the ecosystem for intra- and inter-species diversity, and to help make informed decisions about adaptive management and marine protected …

Genetic Comparison Of Water Molds From Embryos Of Amphibians Rana Cascadae, Bufo Boreas And Pseudacris Regilla, Kori K. Ault, James E. Johnson, Holly C. Pinkart, R. Steven Wagner

All Faculty Scholarship for the College of the Sciences

Water molds that cause the disease saprolegniasis have been implicated in widespread mortality of amphibian embryos. However, because of the limitations of traditional identification methods, water mold species involved in die-offs or utilized in ecological studies often remain unidentified or identified only as Saprolegnia ferax. Furthermore, water mold taxonomy requires revision, so very distinct organisms may all be called S. ferax. Recent DNA-based studies indicate that the diversity of water molds infecting amphibian embryos is significantly higher than what was previously known, but these studies rely on culture methods, which may be biased towards taxa that grow best …

Developmental Programming In Response To Intrauterine Growth Restriction Impairs Myoblast Function And Skeletal Muscle Metabolism, Dustin T. Yates, A.R. Macko, M. Nearing, X. Chen, R.P. Rhoads, Sean W. Limesand

Department of Animal Science: Faculty Publications

Fetal adaptations to placental insufficiency alter postnatal metabolic homeostasis in skeletal muscle by reducing glucose oxidation rates, impairing insulin action, and lowering the proportion of oxidative fibers. In animal models of intrauterine growth restriction (IUGR), skeletalmuscle fibers have lessmyonuclei at birth. This means thatmyoblasts, the sole source formyonuclei accumulation in fibers, are compromised. Fetal hypoglycemia and hypoxemia are complications that result from placental insufficiency. Hypoxemia elevates circulating catecholamines, and chronic hypercatecholaminemia has been shown to reduce fetal muscle development and growth. We have found evidence for adaptations in adrenergic receptor expression profiles in myoblasts and skeletal muscle of IUGR sheep …

Use Of A Complete-Feed Diet (Ramp) To Rapidly Transition Cattle To A Finishing Diet, C. J. Schneider, Brandon L. Nuttelman, Dirk Burken, Terry J. Klopfenstein, Galen E. Erickson

Department of Animal Science: Faculty Publications

A study evaluated transitioning cattle from RAMP to a finishing diet with fewer intermediate step diets and days fed during transition. Yearling crossbred steers (n = 390; BW = 341 ± 14 kg) were blocked and stratified by BW, and assigned randomly within strata to 40 feedlot pens, with 9 or 10 steers per pen. Treatments were different grain adaptation programs (27 or 28 d) involving blends of RAMP and finishing diet. A control adaptation program involved decreasing RAMP and increasing a 62.5% corn finishing diet (62.5% high moisture corn (HMC), 25% sweet bran, 7.5% alfalfa hay (AH), and 5% …

Use Of A Complete-Feed Diet (Ramp) In Grain Adaptation Programs Compared To Traditional Grain Adaptation Programs, C. J. Schneider, Brandon L. Nuttelman, Kelsey M. Rolfe Rolfe, William A. Griffin, Terry J. Klopfenstein, Galen E. Erickson

Department of Animal Science: Faculty Publications

A study evaluated using RAMP to adapt cattle to a high grain finishing diet. Yearling crossbred steers (n = 229; BW = 397 ± 28.4 kg) were consecutively weighed over 2 d, stratified by BW, and assigned randomly within strata to 18 feedlot pens, with 12 or 13 steers per pen. Treatments were imposed during grain adaptation (22 d) by decreasing RAMP (100 to 0%) and increasing finishing diet (0 to 100%). RAMP was fed either as a blend in a 1-diet system which was delivered twice daily (RAMP-1RS) or as 2 daily diets where RAMP was delivered in one …

Occurrence Of Hormonal Residues In Feedlot Cattle Waste, Terry L. Mader, Leslie J. Johnson, Shannon L. Bartelt-Hunt, Daniel D. Snow, William Kranz, Charles Shapiro, Simon Van Donk, David P. Shelton, David Tarkalson, T. C. Zhang, Steve Ensley

Department of Animal Science: Faculty Publications

Two identically designed studies were conducted in separate years at the UNL Haskell Agricultural Laboratory using 192 crossbred heifers (96/study). Within a study heifers (initial weight = 386kg) were randomly assigned to 2 groups (3 42.4 m × 14.6 m pens/group/year): 1) treatment (TRT) animals were administered synthetic hormones via subcutaneous implants [d 1, 36 mg zearalonal; d 35, 140 mg trenbolone acetate (TBA) and 14 mg of 17β-estradiol benzoate (Revalor-H)] and fed Melengesterol Acetate (MGA), and 2) control (CON) animals with no synthetic hormone provided. Throughout each study, feedlot pen surface samples were obtained from 4 equally-sized zones (5 …

Anaerobic Digestion Of Finishing Cattle Manure With And Without Distillers Grains In The Diet., Andrea K. Watson, Terry J. Klopfenstein, Galen E. Erickson, Samodha C. Fernando, Jana L. Harding, Adam L. Shreck

Department of Animal Science: Faculty Publications

Two treatments (cattle diet) were used in anaerobic digestion of finishing cattle manure. Diet 1 contained 82.5% dry rolled corn (DRC) (CONT) and diet 2 contained 40% wet distillers grains plus solubles (DM basis) replacing DRC (WDGS). Cattle were housed in stanchions for 3 d with complete manure collection in a cement pit. Manure (feces and urine) was sampled and analyzed for minerals, DM and OM. Manure collected was weighed into individual allotments based on DM and frozen. Continuously stirred anaerobic digesters (n = 7, 1 L capacity) were inoculated and maintained for 5 mo before the trial to ensure …

Vegfa Family Isoforms Regulate Spermatogonial Stem Cell Homeostasis In Vivo, Kyle C. Caires, Jeanene M. Clopton, Andrea S. Cupp, Derek J. Mclean

Department of Animal Science: Faculty Publications

The objective of the present study was to investigate vascular endothelial growth factor A (VEGFA) isoform regulation of cell fate decisions of spermatogonial stem cells (SSC) in vivo. The expression pattern and cell-specific distribution of VEGF isoforms, receptors, and coreceptors during testis development postnatal d 1–180 suggest a nonvascular function for VEGF regulation of early germ cell homeostasis. Populations of undifferentiated spermatogonia present shortly after birth were positive for VEGF receptor activation as demonstrated by immunohistochemical analysis. Thus, we hypothesized that proangiogenic isoforms of VEGF (VEGFA₁₆₄) stimulate SSC self-renewal, whereas antiangiogenic isoforms of VEGF (VEGFA₁₆₅b) …

Effects Of Feeding Field Peas In Combination With Distillers Grains Plus Solubles In Finishing And Growing Diets On Cattle Performance And Carcass Characteristics, A. C. Pesta, A. H. Titlow, J. A. Hansen, A. L. Berger, S. A. Furman, Matt K. Luebbe, G. E. Erickson, K. H. Jenkins

Department of Animal Science: Faculty Publications

Two studies were conducted to evaluate field peas and wet or dry corn distillers grains with solubles (WDGS and DDGS, respectively) in finishing and growing diets. In Exp. 1, British crossbred steers (n = 352, initial BW 356 ± 27 kg) were used in a randomized block design with factors being 0 or 20% field peas and 0 or 30% WDGS in dry-rolled corn (DRC) based finishing diets (DM basis). There was an interaction (P < 0.01) for DMI and G:F. Feeding WDGS increased ADG (P < 0.01), whereas peas had no effect on ADG (P = 0.33). Including WDGS increased G:F in diets without peas (P < 0.01), but had no impact (P = 0.12) in diets containing peas. Peas increased G:F (P = 0.04) in diets without WDGS, but decreased G:F (P = 0.03) with WDGS. Feeding WDGS increased HCW (P < 0.01). In Exp. 2, Continental crossbred heifers (yr. 1; n = 108, initial BW 338 ± 14 kg) and British crossbred steers (yr. 2; n = 90, initial BW 321 ± 10 kg) were assigned randomly to 1 of 9 pastures. Treatments were supplementation with loose DDGS meal on the ground (GROUND), in a bunk (BUNK) or a 25% field peas, 75% DDGS cube on the ground (CUBE) at equal CP. Final BW and ADG were less (P < 0.01) for GROUND than for CUBE and BUNK, which were similar. These data indicate up to 50% DRC could be replaced by peas and WDGS, and peas are an acceptable binder for DDGS range cubes.

Smooth Bromegrass Pasture Beef Growing Systems: Fertilization Strategies And Economic Analysis, A. K. Watson, T. J. Klopfenstein, Walter H. Schacht, G. E. Erickson, D. R. Mark, Matt K. Luebbe, K. R. Brink, Matthew A. Greenquist

Department of Animal Science: Faculty Publications

In recent years, prices for N fertilizer have increased dramatically, reducing net returns of fertilized pasture systems. A 5-yr study from 2005 to 2009 was conducted to evaluate management strategies and relative differences in profitability for 3 methods of backgrounding calves on smooth bromegrass pastures. Forty-five steers were used each year for a total of 225 animals in a randomized complete block design. Treatments included pastures fertilized in the spring with 90 kg N/ha (FERT), nonfertilized pastures with calves supplemented daily with dried distillers grains plus solubles (DDGS) at 0.6% of BW (SUPP), and control (CONT) pastures that had no …

Murine Gut Microbiota Is Defined By Host Genetics And Modulates Variation Of Metabolic Traits, Autumn M. Mcknite, Maria Elisa Perez-Munoz, Lu Lu, Evan G. Williams, Simon Brewer, Penelope A. Andreux, John W. M. Bastiaansen, Xusheng Wang, Stephen D. Kachman, Johan Auwerx, Robert W. Williams, Andrew K. Benson, Daniel A. Peterson, Daniel C. Ciobanu

Department of Animal Science: Faculty Publications

The gastrointestinal tract harbors a complex and diverse microbiota that has an important role in host metabolism. Microbial diversity is influenced by a combination of environmental and host genetic factors and is associated with several polygenic diseases. In this study we combined next-generation sequencing, genetic mapping, and a set of physiological traits of the BXD mouse population to explore genetic factors that explain differences in gut microbiota and its impact on metabolic traits. Molecular profiling of the gut microbiota revealed important quantitative differences in microbial composition among BXD strains. These differences in gut microbial composition are influenced by host-genetics, which …

Case Study: In Situ Determination Of Protein Digestibility Of Dried Distillers Grains Containing 3 Lipid Concentrations Using A Mobile Bag Method, B. E. Meyer, C. L. Bouma, James C. Macdonald

Department of Animal Science: Faculty Publications

Ethanol producers remove lipid from distillers grains (DG) for applications such as biodiesel production. The effects of the lipid removal on ruminal protein degradability and total-tract CP digestibility of DG are not known. Five ruminally and duodenally cannulated Angus-cross steers (BW = 434 ± 15 kg) were used to incubate in situ bags for determination of protein digestibility of low-lipid (5.54%) DG, medium-lipid (8.40%) DG, high-lipid (12.46%) DG, and cottonseed meal. Ingredients were weighed into individual in situ bags and incubated in the ventral sac of the rumen for 16 h. After ruminal incubation and simulated abomasal digestion, bags were …

Dried Distillers Grains As A Substitute For Grazed Forage, L. A. Stalker, T. J. Klopfenstein, Walter H. Schacht, J. D. Volesky

Department of Animal Science: Faculty Publications

A 2-yr study evaluated effects of feeding dried distillers grains (DDG) to yearlings grazing native range at greaterthan- recommended stocking rates on BW gain, grazed forage quality, and forage disappearance. Thirty-six paddocks were assigned randomly to 1 of 3 treatments: 1) control, stocked at a moderate stocking rate (1.48 animal unit months/ha in yr 1, 1.06 animal unit months/ha in yr 2) with no DDG; 2) double stocked, in which stocking rate was exactly twice the control with no DDG; and 3) double stocked with 2.27 kg/d (DM) of DDG per animal. Six paddocks per treatment replication were grazed in …

Technical Note: Estimating Beef-Cattle Forage Demand: Evaluating The Animal Unit Concept, T. L. Meyer, L. A. Stalker, J. D. Volesky, D. C. Adams, R. N. Funston, T. J. Klopfenstein, Walter H. Schacht

Department of Animal Science: Faculty Publications

The objective of this experiment was to evaluate the effect of BW and physiological status of a beef animal on forage intake. The experiment was repeated over 2 yr with 6 replications of 3 treatments per year: cow-calf pair (CCP, BW = 629 kg), nonlactating cow (NLC, BW = 503 kg), and yearling steer (YS, BW = 305 kg). The CCP was treated as one unit, with the sum of cow BW and calf BW comprising CCP BW. Calves averaged 42 d of age and 73 kg at the start of the experiment each year. Animals were housed in individual …

The Balance Of Proangiogenic And Antiangiogenic Vegfa Isoforms Regulate Follicle Development, Renee M. Mcfee, Timonthy G. Clopton, Andrea S. Cupp

Department of Animal Science: Faculty Publications

Vascular endothelial growth factor A (VEGFA) has been extensively studied because of its role in follicular development and is a principal angiogenic factor essential for angiogenesis. Since vascularization of the theca layer increases as follicles progress in size through preantral and antral stages, VEGFA might influence follicle growth via the regulation of angiogenesis. However, VEGFA might also influence follicular development through nonangiogenicmechanisms, since its expression has been localized in nonvascular follicles and cells. Alternative mRNA splicing of eight exons from the VEGFA gene results in the formation of various VEGFA isoforms. Each isoform has unique properties and is identified by …

A High Density Snp Array For The Domestic Horse And Extant Perissodactyla: Utility For Association Mapping, Genetic Diversity, And Phylogeny Studies, Molly E. Mccue, Danika L. Bannasch, Jessica Lynn Petersen, Jessica Gurr, Ernie Bailey, Matthew M. Binns, Ottmar Distl, Gérard Guérin, Telhisa Hasegawa, Emmeline W. Hill, Tosso Leeb, Gabriella Lindgren, M. Cecilia T. Penedo, Knut H. Røed, Oliver A. Ryder, June E. Swinburne, Teruaki Tozaki, Stephanie J. Valberg, Mark Vaudin, Kerstin Lindblad-Toh, Claire M. Wade, James R. Mickelson

Department of Animal Science: Faculty Publications

An equine SNP genotyping array was developed and evaluated on a panel of samples representing 14 domestic horse breeds and 18 evolutionarily related species. More than 54,000 polymorphic SNPs provided an average inter-SNP spacing of ~43 kb. The mean minor allele frequency across domestic horse breeds was 0.23, and the number of polymorphic SNPs within breeds ranged from 43,287 to 52,085. Genome-wide linkage disequilibrium (LD) in most breeds declined rapidly over the first 50–100 kb and reached background levels within 1–2 Mb. The extent of LD and the level of inbreeding were highest in the Thoroughbred and lowest in the …

Index Selection In Terminal Sires Improves Early Lamb Growth, G. C. Márquez, W. Haresign, M. H. Davies, G. C. Emmans, Rainer Roehe, L Bünger, G. Simm, Ronald M. Lewis

Department of Animal Science: Faculty Publications

The use of terminal sires (TS) for crossbreeding is integral to the UK sheep industry where approximately 71% of market lambs are sired by TS rams. Early growth of these crossbred lambs affects profitability. The objectives of this study were i) to evaluate the effectiveness of index selection among TS on BW and ADG of their crossbred offspring; and ii) to compare the efficacy of that selection within TS breeds. The most widely used TS breeds in the United Kingdom are Charollais, Suffolk, and Texel. These participated in sire referencing schemes in which they were evaluated on a lean growth …

Genome Empowerment For The Puerto Rican Parrot – Amazona Vittata, Stephen J. O'Brien

Biology Faculty Articles

A unique community-funded project in Puerto Rico has launched whole-genome sequencing of the critically endangered Puerto Rican Parrot (Amazona vittata), with interpretation by genome bioinformaticians and students, and deposition into public online databases. This is the first article that focuses on the whole genome of a parrot species, one endemic to the USA and recently threatened with extinction. It provides invaluable conservation tools and a vivid example of hopeful prospects for future genome assessment of so many new species. It also demonstrates inventive ways for smaller institutions to contribute to a field largely considered the domain of large …

Hslic Fall 2012 Scholarship Committee Report, Ann Jordan

Ann Jordan

No abstract provided.

Gene Number Determination And Genetic Polymorphism Of The Gamma Delta T Cell Co-Receptor Wc1 Genes, Chuang Chen, Carolyn Ta Herzig, Leeson J. Alexander, John W. Keele, Tara G. Mcdaneld, Janice C. Telfer, Cynthia L. Brown

Janice C. Telfer

Background: WC1 co-receptors belong to the scavenger receptor cysteine-rich (SRCR) superfamily and are encoded by a multi-gene family. Expression of particular WC1 genes defines functional subpopulations of WC1+ γδ T cells. We have previously identified partial or complete genomic sequences for thirteen different WC1 genes through annotation of the bovine genome Btau_3.1 build. We also identified two WC1 cDNA sequences from other cattle that did not correspond to sequences in the Btau_3.1 build. Their absence in the Btau_3.1 build may have reflected gaps in the genome assembly or polymorphisms among animals. Since the response of γδ T cells to bacterial …

Subspecific Status Of The Korean Tiger Inferred By Ancient Dna Analysis, Mu-Yeong Lee, Jee Yun Hyun, Seo-Jin Lee, Junghwa An, Eunok Lee, Mi-Sook Min, Junpei Kimura, Shin-Ichirio Kawada, Nozomi Kurihara, Shu-Jin Luo, Stephen J. O'Brien, Warren E. Johnson, Hang Lee

Biology Faculty Articles

The tiger population that once inhabited the Korean peninsula was initially considered a unique subspecies (Panthera tigris coreensis), distinct from the Amur tiger of the Russian Far East (P. t. altaica). However, in the following decades, the population of P. t. coreensis was classified as P. t. altaica and hence forth the two populations have been considered the same subspecies. From an ecological point of view, the classification of the Korean tiger population as P. t. altaica is a plausible conclusion. Historically, there were no major dispersal barriers between the Korean peninsula and the habitat of …

Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo

Dissertations, Theses, and Masters Projects

Squaloids (Order Squaliformes) are a highle diverse group of mostly deepwater habitats (> 200 m). Many species are regularly caught in commercial fisheries worldwide but their low productivity and correspondingly low intrinsic rebound potentials make them particularly vulnerable to population depletion and overexploitation. of special concern to fisheries management and conservation efforts are the spiny dogfish Squalus acanthias, the leafscale gulper shark Centrophorus squamosus and the Portuguese dogfish Centroscymnus coelolepis. These taxa have recently been declared overfished in several parts of each species' distribution but management efforts have been made to recover the "stocks" without a good understanding of the …

Inheritance Of Humeral Spotting In The Croaking Gourami (Osphronemidae: Trichopsis Vittatus), Jack Frankel, Lisa Alder-Golden, Andre Porter

Department of Biology Faculty Publications

The croaking gourami (Trichopsis vittatus) exhibits two phenotypes associated with humeral spotting. Fish possess a prominent, dark humeral patch or spot located behind the operculum or lack this spotting pattern. Segregation patterns observed from the progenies of eleven different crosses support the hypothesis that the inheritance of humeral spotting in T. vittatus is controlled by the action of a single autosomal locus, with complete dominance of the allele controlling the spotted phenotype.

Estimation Of Breed-Specific Heterosis Effects For Birth, Weaning And Yearling Weight In Cattle., L. N. Schiermiester, R. M. Thallman, L. A. Kuehn, M. L. Spangler

Department of Animal Science: Faculty Publications

Heterosis, assumed proportional to expected breed heterozygosity, was calculated for 4,835 individuals with birth, weaning and yearling weight records from Cycle VII of the U.S. Meat Animal Research Center Germplasm Evaluation Program. Heterosis was further estimated by proportions of British x British (BxB), British x Continental (BxC) and Continental x Continental (CxC) crosses. Angus and Red Angus were considered a single breed for estimation of heterosis. Direct heritability estimates (SE) for birth, weaning and yearling weight were 0.39 (0.05), 0.18 (0.04) and .40 (0.06), respectively. The BxB covariate was significant and BxC approached significance for weaning weight. The BxB proportion …