Genomics: What is it?
Genomics & Performance data produce increased EBV Reliabilities
When it comes to making mating decisions, the cattle industry has relied heavily on phenotype, performance data, and carcass data for many years. The phenotype of an animal was often the determining factor for breeding program decisions. Recently, however, more breeders are looking towards genomics to help them make informed mating decision. Generally speaking, genomics is the study of DNA and genomes with regard to structure, function, evolution, and mapping. It looks at specific sets of genes and genetic material found in an animal’s DNA in an effort to make predictions of an animal’s future performance and potential for a variety of traits.
While you can learn a lot by observing the phenotype of an animal, it does not predict how well, or how poorly, that animal will perform “on the rail”. It can take many years for accurate data to be collected on a sire that was chosen based on phenotype or pedigree for a breeding program. This is because it requires a large number of progeny to be on the ground before that sire can be proven through data collection. In addition, some data cannot be collected until after slaughter. If the data after slaughter shows great scores for meat tenderness, marbling, or carcass-grade, the ability to collect semen for breeding from that animal may have been lost if he is dead or sold.
Example of DNA Structure
Genomics, on the other hand, provides insight into an animal’s DNA, something that cannot be seen by the naked eye. DNA is the genetic code that is passed from one generation to the next and determines how an organism grows, what it looks like, and how it performs. Using genomic testing can save breeders a lot of time and money because they do not have to wait until there are a substantial number of progeny on the ground to get an increased accuracy EBV prediction of the potential of a sire. Through testing at birth with the use of Single Nucleotide Polymorphism (SNP) technology, breeders can now gain knowledge on how well that animal, and eventually its offspring, will perform. Genomic tests of new cattle look for similarities in these SNP locations compared to proven cattle already in the database with performance and carcass data to get an estimation of the potential for the animal being tested.
Genomics also allows for a decreased generation interval, increasing the rate of genetic gain.
SNP tests are not the only method for genetic testing currently available; however, it is one of the most widely used methods and has low genotype error rates. SNP tests utilize blood samples, tissue samples, or tail hair samples to run testing on an animal’s genome. Genomes can be assessed for various traits related to calving ease, weaning weight, carcass weight, marbling, etc. In addition, genomes can be assessed to determine parental lineage (i.e. parent verification) and genetic abnormalities. Results from any and/or all of these assessments provide breeders with the ability to make more informed decisions when it comes to their breeding programs and general herd management.
While genomics can be a valuable tool to assess what genes, traits, strengths, or weaknesses animals inherited from each parent, it is not an absolute measure of potential or a guarantee of performance. Remember, genomics in Wagyu still have relatively low reliabilities and are only as good as the data that was originally input into the system. There are many applications for genomics from national sire selection, within herd analysis, and even selection and decision making for full siblings. This valuable technology will play an important role in the future of the Wagyu breed and is something to incorporate into your herd management and decision making.