Displaying Genetic Conditions on a Pedigree

written by Matt Woolfolk, Director of Performance Programs

Genetic conditions are certainly something that we have to pay attention to in the Shorthorn breed. Whether it is TH, PHA, or DS, each of these can cause detrimental effects in your herd if they are not closely monitored. I’m not going to go into the specifics of each of these conditions and how they can impact a calf in this article. Instead, I will focus on some of the nomenclature and symbols that you might see when researching pedigrees in DigitalBeef or if you look at your registration certificates received from ASA.

When studying cattle in DigitalBeef, you might have noticed various colored notations of THC, DSF, or other similar abbreviations beside animal names on a pedigree. If you didn’t know what they signified, you are in luck with this article! There are three colors that you will see for these abbreviations: red, green and yellow. I will explain below what they signify.

Red: If you see a THC, PHAC, or DSC on an animal’s registration certificate or on its Pedigree tab of DigitalBeef, then that animal has been tested and confirmed as a carrier for whichever condition you see noted on the paper. In order to have an animal test as a carrier of TH, PHA, or DS, one of the parents must be a carrier of that condition. Two parents that are tested free should not be able to produce a THC, PHAC, or DSC calf. As always, extra precaution should be taken in regards to breeding 2 carriers of the same genetic condition to each other, as doing so gives you a 25% chance of producing a homozygous calf that will exhibit the signs of TH, PHA, or DS. I would not recommend breeding two carriers of the same genetic condition to each other.

Green: A THF, PHAF, or DSF on a registration paper or in the Pedigree tab on DigitalBeef indicate that the animal in question has been tested free of the specific genetic condition. Breeding a THF, PHAF, or DSF cow to a bull that is a carrier for any of these conditions CAN produce a calf that is a carrier, but the resulting calf being affected with TH, PHA, or DS will not happen. An animal MUST be tested as free of these conditions to receive the THF, PHAF, or DSF designation on a paper or in the system. Animals that are “free by pedigree” without being tested will not appear with this designation on the paper or in the system.

Yellow: The most difficult of the colored markers to understand, an animal with a TH, PHA, or DS on their registration paper or on the Pedigree tab on their Animal Info in DigitalBeef is listed as an untested potential carrier for the designated condition. An animal with any of these designations is NOT tested for the genetic condition listed in yellow. Instead, these animals have a tested carrier (THC, PHAC, or DSC) within 4 generations in their pedigree, without an animal tested free (THF, PHAF, or DSF) between them on the pedigree. For example, a calf is listed as PHA because his great-grandsire is PHAC, and none of the cattle in the direct line back to that great-grandsire in the pedigree have been tested as PHAF. The simplest way to remove the golden letters from a pedigree is to test the animal in question to officially determine if they are free or a carrier for the genetic condition. If an animal does not have a yellow designation, that means there are no tested carriers within 4 generations on the pedigree. That does not mean that you might not find a carrier 5 or more generations back. The DigitalBeef system only checks back for generations to signify a potential carrier.

Genetic conditions in your herd can easily be managed by doing your homework and taking extra precaution in your breeding program. Hopefully, these color-coded designations on your papers and in DigitalBeef help you when you’re making those decisions to identify animals that are tested for genetic conditions, or those that might be worth the investment to find out their status with a genetic test.

With this being the December issue, I want to take the time to wish you all a Merry Christmas. The year 2019 has not been an easy one in the agricultural community. From weather to policy to market volatility, there has been a lot of difficulty thrown at farmers and ranchers. However, this time of year we still get to celebrate the greatest gift that we could ever dream of receiving: Jesus Christ was born on this Earth (in a barn of all places!), sent here as our Savior. Even if times are tough, that’s a gift still worth celebrating.

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