Featured Post

Dr. Jamie Courter is your Mizzou Beef Genetics Extension Specialist

Image
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
Post a Comment

BIF 2017: Genetics of reproduction project

Alison Van Eenennaam
UC-Davis

The grant dubbed the "heifer fertility project" is really looking for embryonic lethal variants. These are DNA variants that if an embryo inherits two copies of the variant, that embryo is aborted. The DNA variant breaks a gene. If an animal inherits two copies, it can't live.

The project sequenced the entire genome of hundreds of cattle. This is not genotyping thousands of DNA variants, it is looking at all 2.6 billion base pairs of the genome. From sequencing these bulls, the team identified millions of DNA variants. They selected 200,000 of these DNA variants that are predicted to affect proteins encoded by genes to build a new SNP chip. This chip is called the GGP-F250.

They then genotyped 17,000 cattle with the GGP-F250 chip. Taylor then looked for DNA variants for which there are not observed in two copies. If a DNA variant is at high frequency, but is never seen as two copies, then we have evidence that this is a lethal DNA variant. There appears to be hundreds of these lethal variants in Angus cattle.

Van Eenannaam is working on the producer applications from this grant. If there are lots of DNA variants responsible for embryonic loss, we will have to strategically manage them. If we don't use animals that carry embryonic lethal variants, we will basically be practicing single trait selection. If you haven't heard, single trait selection is bad!

What is important is to never mate a carrier to another carrier of the same lethal variant. Mate selection tools allow us to do this in a sophisticated way.

For more information, see http://beefreproduction.org/.


MateSel is a software program for mate selection. MateSel works to increase genetic merit while limiting inbreeding. Van Eenannaam's graduate student showed simulations using MateSel.
There is a trade-off between never using a carrier and economic genetic progress.

Location: Athens, GA, USA

Comments

Post a Comment

Popular posts from this blog

Show-Me-Select Board Approves Genomic Testing Requirement for Natural Service Sires

Image
All bulls purchased after February 1st, 2019 for use as natural service sires in the Show-Me-Select Replacement Heifer Program ™  must be DNA tested to have genomic-enhanced EPDs. All bulls used as natural service sires after February 1st, 2020 must have genomic-enhanced EPDs, regardless of when they were purchased. Seedstock producers classifying bulls as Show-Me-Select qualified in sale books must have genomic-enhanced EPDs on those lots. Bulls purchased prior to February 1st, 2019 will be grandfathered into the program, as is the common practice with all natural service sires. However, this grandfather grace period will end February 1st, 2020. At that time for a bull to qualify for use in the program, it must have genomic-enhanced EPDs. Why the change? The Show-Me-Select Replacement Heifer Program has the goal of producing premium heifers that perform predictably as 2 year olds. The program has a history of requiring Show-Me-Select producers to go beyond typical cat
Read more

New Show-Me-Select Sire EPD Requirements Announced

Image
At the January 4th Show-Me-Select Board of Directors meeting, new service sire EPD requirements were approved. All sires, artificial insemination and natural service, must meet minimum Calving Ease Direct (CED) EPD requirements. In addition to yearly updates, two changes were made. First, no Birth Weight EPD requirement will be published. All commonly used breeds now have CED EPDs available. Second, all breeds in the International Genetic Solutions (IGS) genetic evaluation are now set to a common requirement. In the summer of 2018, breeds within the International Genetic Solutions switched to a single-step BOLT multi-breed genetic evaluation. The EPDs for animals in the IGS genetic evaluation are directly comparable across breeds. In 2017, the Red Angus requirement for CED was a CED of 8, which represents the 30th percentile. Less than 5% percent of heifers breed to a bull with a CED EPD of 8 or larger had calving difficulty. We feel that this require is meeting the need to re
Read more