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Published online August 10, 2017
758 Understanding the nature of complex phenotypes
in beef cattle using systems biology. A. Canovas*1,
M. G. Thomas2, J. Casellas3, and J. F. Medrano4,
Department of Animal Biosciences, University of
Guelph, Guelph, ON, Canada, 2Department of Animal
Sciences, Colorado State University, Fort Collins,
Universitat Autònoma de Barcelona, Bellaterra
(Barcelona), Spain, 4Department of Animal Science,
University of California, Davis.
In recent years, breeders have combined the use of phenotypic appraisal and the estimation of breeding values (EPD)
to make genetic selection decisions in beef and dairy cattle
that have resulted in a steady genetic gain of 2% per year.
However, the most extensive application of genomics has occurred in the dairy industry with the estimation of molecular
breeding values that has improved selection efficiency to a
much higher order of magnitude. Despite a growing molecular and physiological understanding of complex traits, little is
known about the genes determining the traits and their precise
function, and a significant unexplained source of variation of
phenotypes remains in livestock. Within this context, a more
complete understanding of the genes and regulatory pathways
and networks involved in economically important traits (i.e.
fertility and reproduction, feed efficiency, meat quality and
carcass traits) in beef cattle will provide knowledge to help
improve genetic selection and reproductive management.
Currently, with all the new available technologies in livestock combined with statistical methodologies, the integration of structural and functional genomics information with
other –OMICS into a systems biology approach has allowed
development of a better biological understanding of phenotypes complementing the traditional genetic tools and further
advance identification of functional genes. As part of the genomics tool box and the HD-genotyping SNP chips, whole genome sequencing technologies are now available in cattle and
extensively utilized in genetic improvement. As a part of high
throughput tools available for genomic analysis, RNA-Sequencing allows measuring not only gene expression, but also
examining genome structure identifying SNP and other structural variation such as insertions, deletions and splice variants. The expectation is that the integration of all these types
of genomic data will accelerate the genetic improvement by
improving accuracy of selection and reducing the generation
interval. Combining the information from the –OMICS technologies (i.e., transcriptomics, metagenomics, metabolomics,
amongst several others) together with metabolic pathways
and functional/biological analysis into a systems biology approach allows the identification of functional SNP increasing
the accuracy of selection. The particular benefits of new integrated high-throughput genomics technologies within a systems biology approach will most likely be used to accelerate
the genetic improvement of those traits that are difficult to
measure such as health, feed efficiency, methane emission and
fertility and reproduction traits in beef cattle.
Key words: OMICS technologies, Genetical Genomics,
Systems biology
810 Glyphosate residues in feed. D. A. Goldstein*,
Monsanto, St. Louis, MO.
There is widespread confusion on pesticide residue tolerances
in feed and food. Assumptions that tolerances are safety-based
limits and that exceedances will result in a risk of illness in
animals or humans are generally incorrect. Tolerances are set
based on actual residue values following proper application in
accordance with label instructions and are designed primarily
to enforce proper application. Although tolerances in feed must
ultimately protect both animals and animal product consumers
(through meat, milk, and eggs), the large majority of tolerances
fall far below any level of safety concern. Glyphosate residues
occur in animal feed because of the use for in-crop weed control in glyphosate-tolerant cropping systems and some use as a
preharvest desiccating agent. Based on extensive data, allowable glyphosate tolerances in feed are set far below levels of
health concern. Animal feed efficiency and other data demonstrate no adverse effects of glyphosate residues (or genetically
modified crops) on animal performance measures. Actual measurements of glyphosate in meat, milk, and eggs are generally
undetectable, and overall human intake is far below levels of
regulatory concern as reflected in human biomonitoring data.
Key Words: glyphosate, pesticide, residue
829 Controlling meat quality through product
functionality enhancement. H. L. Bruce*, University
of Alberta, Department of Agricultural, Food and
Nutritional Science, Edmonton, AB, Canada.
Meat can be considered a functional food because it is an
excellent source of protein; minerals such as iron, zinc, and
selenium; and B vitamins, but recent associations of red meat
with diseases such as cancer and cardiovascular disease provide an impetus to look at increasing the healthfulness of
meat. Modification of the eating quality of meat is currently
accomplished through management of animal breed and/or
growth-enhancing pharmaceuticals, with gene marker selection for meat tenderness commercially available in cattle and
under investigation in pigs. Other antemortem meat quality
enhancements include alteration of fat content and fatty acid
composition through animal diet; supplementation of animals
with vitamins D and E to improve meat tenderness and shelf
life, respectively; and provision of glucose and electrolytes
prior to slaughter to decrease the likelihood of dark cutting
and improve meat color. Given that ground, seasoned, cured,
and injected/tenderized products are readily accepted in the
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