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Dr. Jamie Courter is your Mizzou Beef Genetics Extension Specialist

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By Jared E. Decker Many of you have probably noticed that things have been a lot less active on the A Steak in Genomics™   blog, but you probably haven't known why. In January 2021, I was named the Wurdack Chair in Animal Genomics at Mizzou, and I now focus on research, with a little bit of teaching. I no longer have an extension appointment. But, with exciting news, the blog is about to become a lot more active! Jamie Courter began as the new MU Extension state beef genetics specialist in the Division of Animal Sciences on September 1, 2023. I have known Jamie for several years, meeting her at BIF when she was a Masters student. I have been impressed by Jamie in my interactions with her since that time.  Dr. Courter and I have been working closely together the last 6 weeks, and I am excited to work together to serve the beef industry for years to come! Jamie holds a bachelor’s degree in animal science from North Carolina State University and earned a master's degree in animal
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ASA Fall Focus: Application of Genomic Technology to Optimize Herd Replacement and Produce Elite Breeding Stock

Mahdi Saatchi
Lead Genomicist
International Genetic Solutions

Imagine a sire who is heterozygous (one A variant and one B variant) for a DNA position. At that same position a dam  is also heterozygous.
If we consider two progeny of this pair of sire and dam, they can be 0% related to 100% related at this position.

Calf 1 Calf 2 Relationship
A/A A/A 100%
A/A A/B 50%
A/A B/B 0%
A/B A/A 50%
A/B A/B 100%
A/B B/B 50%
B/B A/A 0%
B/B A/B 50%
B/B B/B 100%

If we apply this to the entire genome, we expect full siblings to share 50% of their DNA. But, just as the relationships can vary at a single locus, the relationships can vary for the entire genome. In chicken data, researchers see that the relationship between siblings ranges from 0.2 to 0.7.

Fig. 2 from Lourenco et al. 2015  http://gsejournal.biomedcentral.com/articles/10.1186/s12711-015-0137-1#Fig2
By more precisely measuring the relationship between animals, genomics allows us to more precisely predict an animal's genetic merit.

Genomics allows us to improve several parts of the key equation for genetic change. Genomics allows us to have more accurate selection decisions, increase the selection intensity and decrease the generation interval.

Genomic predictions have previously been shown to be accurate for Simmental cattle (Saatchi et al. 2012).

Genomic predictions are reliably predicting yearling weight. Genomic predictions are explaining real differences in yearling weight. Based only on the genomic prediction (molecular breeding value), there is a 100 pound difference between animals in the top 25% and bottom 25% of animals based on the genomic prediction.

Genomic information can be used for more than just producing genomic-enhanced EPDs. Saatchi points out that strings of DNA variants (called haplotypes) are sometimes never observed in two copies in an animal. If these haplotypes are never seen it two copies it likely means that they carry a variant that is responsible for the loss of pregnancies.

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