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Full-Text Articles in Life Sciences

Evaluation Of Fixed Sources Of Variation And Estimation Of Genetic Parameters For Incidence Of Bovine Respiratory Disease In Preweaned Calves And Feedlot Cattle, M. J. Schneider, Richard G. Tait Jr., Marshall V. Ruble, W. Darrell Busby, James M. Reecy Apr 2013

Evaluation Of Fixed Sources Of Variation And Estimation Of Genetic Parameters For Incidence Of Bovine Respiratory Disease In Preweaned Calves And Feedlot Cattle, M. J. Schneider, Richard G. Tait Jr., Marshall V. Ruble, W. Darrell Busby, James M. Reecy

Richard G. Tait Jr.

The primary objective of this study was to estimate variance components and heritability of bovine respiratory disease (BRD) incidence in beef calves before weaning and during the finishing phase. The second objective was to investigate the impact of BRD incidence and treatment frequency on performance and carcass traits. Bovine respiratory disease is the biggest and most costly health challenge facing the cattle industry. The 2 populations used consisted of 1,519 preweaned calves and 3,277 head of feedlot cattle. The incidence rate of BRD in preweaned calves was 11.39%, and among treated cattle, 82.1% were treated once ...


Heritable Melanism And Parasitic Infection Both Result In Black-Spotted Mosquitofish, Lisa Horth, David Gauthier, Wolfgang Vogelbein Jan 2013

Heritable Melanism And Parasitic Infection Both Result In Black-Spotted Mosquitofish, Lisa Horth, David Gauthier, Wolfgang Vogelbein

Biological Sciences Faculty Publications

Male Gamhusia holhrooki (Eastern Mosquitofish) express a heritable pigmentation polymorphism approximate to 99% of males are silver, and only approximate to 1% have a melanic, black-spotted pattern. Sex-linkage, an autosomal modifier, and temperature control the expression of this heritable melanism. In many teleosts, melanin also accumulates around the site of parasitic invasion. We have identified black-spot disease in wild mosquitofish from their native habitat. Here, we demonstrate convergence upon the black-pigmented phenotype through two means: 1) heritable melanism, and 2) melanic spotting on the silver genotype that results from infection with immature encysted trematodes. Females are silver and express greater ...


Investigating The Role Of Epibiotic Bacteria In Defense Against Chytridiomycosis In The Green Frog, Lithobates Clamitans, Sarah Nalven Jan 2013

Investigating The Role Of Epibiotic Bacteria In Defense Against Chytridiomycosis In The Green Frog, Lithobates Clamitans, Sarah Nalven

Honors Theses

Amphibian populations have been declining for several decades, in part due to the emerging fungal skin disease, chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Chytridiomycosis has caused extinctions and extirpations in many parts of the world, but its influence varies across species, populations, and individuals. The Green Frog (Lithobates clamitans), which inhabits the eastern half of the United States, seems capable of sustaining Bd infections without experiencing die-offs. It is possible that the Green Frog's epibiotic bacteria are contributing to its defense against Bd as the epibiotic bacteria of several amphibian species are known to play a ...


Integrated Genomic Approaches To Enhance Genetic Resistance In Chickens, Hans H. Cheng, Pete Kaiser, Susan J. Lamont Jan 2013

Integrated Genomic Approaches To Enhance Genetic Resistance In Chickens, Hans H. Cheng, Pete Kaiser, Susan J. Lamont

Animal Science Publications

The chicken has led the way among agricultural animal species in infectious disease control and, in particular, selection for genetic resistance. The generation of the chicken genome sequence and the availability of other empowering tools and resources greatly enhance the ability to select for enhanced disease resistance via genetic markers and to understand more deeply the biological basis of host resistance. In this review, we discuss how integrated genomic approaches are able to identify specific genes and genetic markers associated with disease resistance, give select examples of contemporary work involving various genomic strategies to identify disease resistance genes, and finish ...


Metamodels For Transdisciplinary Analysis Of Wildlife Population Dynamics, Robert C. Lacy, Philip S. Miller, Philip J. Nyhus, J. P. Pollak, B. E. Raboy, S. L. Zeigler Dec 2012

Metamodels For Transdisciplinary Analysis Of Wildlife Population Dynamics, Robert C. Lacy, Philip S. Miller, Philip J. Nyhus, J. P. Pollak, B. E. Raboy, S. L. Zeigler

Philip J. Nyhus

Wildlife population models have been criticized for their narrow disciplinary perspective when analyzing complexity in coupled biological – physical – human systems. We describe a “metamodel” approach to species risk assessment when diverse threats act at different spatiotemporal scales, interact in non-linear ways, and are addressed by distinct disciplines. A metamodel links discrete, individual models that depict components of a complex system, governing the flow of information among models and the sequence of simulated events. Each model simulates processes specific to its disciplinary realm while being informed of changes in other metamodel components by accessing common descriptors of the system, populations, and ...