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Questions
About GE-EPDs

This list of questions has been compiled from member inquires on GE-EPDs using the GE-EPD question portal located below. These questions have been answered as simply as possible, therefore there may be some level of detail that was excluded for ease of understanding. These questions are fairly specific to certain aspects of GE-EPDs. For a more robust description of how genomic testing works and how GE-EPDs are generated please see read the articles featured in the January 2014 Digest on Canadian Genomics.

  1. Is the cost associated with generating GE-EPDs on an animal included in the cost of parentage and abnormalities testing?
  2. Once an animal has had a GE-EPD test done, will their GE-EPD values be better than their previous EPD value?
  3. Will every animal that is registered with the association have GE-EPDs?
  4. What is the difference between the SNP parentage test and the High Density SNP test for the GE-EPDs?
  5. How is accuracy affected by incorporating genomics with EPDs (GE-EPDs)?
  6. Is every breed in Canada getting GE-EPDs? Can we compare them?
  7. Why would I want my cattle to have GE-EPDs?
  8. Does the breed average still matter?
  9. 50K DNA was promoted in its first application as providing the same proof as one calf crop (20-25 calves). That has now been revised to the same proof by 5 calves off of the same sire. Is this expected to be the final comparison?
  10. A GE tested bull/ female is purchased from the United States, do we have to re-test the animal in Canada?
  11. I have submitted DNA samples (blood, hair) over the last few years. Are these samples stored indefinitely? Can my DNA'd cattle that are no longer alive be used to increase the EPD accuracy on my cattle today?
  12. How do you match dam and possible sire EPDs to know if they will be a good match?
  13. How do you determine EPD's on cattle that have no sire or dam EPD information?
Still have a questions about GE-EPDs? Submit them using the form below.

  1. Is the cost associated with generating GE-EPDs on an animal included in the cost of parentage and abnormalities testing?
  2. No, the cost to have an animal tested to generate GE-EPDs is not included in the cost of parentage testing. There is a specific test listed on the CHA's fee schedule. The "High Density SNP Test" is the test used to generate the GE-EPDs. Both tests are SNP tests; however the parentage and abnormalities test uses a fraction of the SNPs used in the test for GE-EPDs.

  3. Once an animal has had a GE-EPD test done, will their GE-EPD values be better than their previous EPD value?
  4. The GE-EPD test doesn't directly make an animal's EPD values better or worse; instead it increases the accuracy of the EPD prediction over that of basic performance records (i.e. Birth weight, calving ease and so on). After incorporating the genomic portion of the evaluation the new genomically enhanced EPD (GE-EPD) value may be higher or lower than that of the original prediction; however the accuracy will have increased compared to the non-genomic/traditional EPD.

  5. Will every animal that is registered with the association have GE-EPDs?
  6. Every animal that is registered with the association will not have GE-EPDs. The only animals that GE-EPDs will be generated on are those that have DNA submitted for the High Density SNP test. Also, in generating the mathematical model to develop this technology, approximately 1600 Canadian Hereford animals have been genotyped (High Density SNP tested) over the past year; all these animals will generate GE-EPDs automatically.

  7. What is the difference between the SNP parentage test and the High Density SNP test for the GE-EPDs?
  8. SNP parentage test uses around 100 SNPs to validate parentage on an animal. High Density SNP tests use over 70,000 SNPs which acts to increase the accuracy of the EPD prediction by measuring the genetic ability (ie. the make-up of the animal's genome) of the animal to perform.

  9. How is accuracy affected by incorporating genomics with EPDs (GE-EPDs)?
  10. GE-EPDs increase the accuracy of prediction (Acc.) over a traditional EPD evaluation. This is done by observing the relationship between over 70,000 different spots in the genome and each trait of interest (BW,WW etc)

  11. Is every breed in Canada getting GE-EPDs? Can we compare them?
  12. Most breeds in Canada are on the path, or are considering developing GE-EPDs, however only Angus and Simmentals have active programs currently. The CHA's GE-EPDs will be available in the near future. The comparison of GE-EPDs across the breeds that have these active programs is not possible; however, Canadian, American, Argentinian and Uruguayan Hereford GE-EPDs will be directly comparable to one another due to our partnership in PACE.

    Still have a questions about GE-EPDs? Submit them using the form below.

  13. Why would I want my cattle to have GE-EPDs?
  14. GE-EPDs will be most useful in cases where more accuracy in the EPD evaluation is desired. Higher accuracies will allow breeders and buyers to make more informed decisions when selecting based on EPDs. Increases in accuracy will be the largest in younger animals or animals that have little phenotypic data recorded (weights, ultrasound, progeny records).
    Example: If a producer had a group of four flush siblings, these animals by tradition would have very similar EPD evaluations. If a breeder wanted to have a better understanding how they compared to one another on EPDs, the cattle would be genotyped which would increase the accuracy of the EPDs and give the breeders a better understanding of how the siblings rank based on their new evaluations

  15. Does the breed average still matter?
  16. Yes, breed average still matters within GE-EPDs. A point of reference within the breed is always needed with any evaluation. The interpretation of a GE-EPD is the exact same as a traditional EPD. The only difference between a GE-EPD and an EPD is that one is Genomically enhanced (GE). To fully interpret a GE-EPD or EPD value you must know breed average for the trait and the accuracy.

  17. 50K DNA was promoted in its first application as providing the same proof as one calf crop (20-25 calves). That has now been revised to the same proof by 5 calves off of the same sire. Is this expected to be the final comparison?
  18. Firstly, because we're still in the process of developing our prediction equations we can't definitively tell what the accuracy gains will be for Canadian Hereford GE-EPDs at this very moment. The accuracy gains from genomic testing will vary based on the trait of interest. For example, the accuracy gains due to genomic enhancement of the EPD will be different for birth weight and stayability. The easiest way to understand gains in accuracy is to describe them by the means of progeny equivalents. This is a way to simulate how many observed progeny records would be equal to the gain in accuracy.
    Using American Simmental data, if you genomically test a young animal the GE-EPD will yield gains in accuracy that are equal to 1 – 28 progeny equivalents. The amount of accuracy gained is trait dependant. Some traits will see large gains in accuracy and some will be much smaller.
    Once the CHA prediction equations have been completed progeny equivalents and accuracy gains, for each trait, from genomic testing will be posted.

  19. A GE tested bull/ female is purchased from the United States, do we have to re-test the animal in Canada?
  20. No, you would not have to re-test an animal that's already been genomically tested in the United States and vice versa once the CHA is actively reporting GE-EPDs. These animals will have the same evaluation due to PACE.

  21. I have submitted DNA samples (blood, hair) over the last few years. Are these samples stored indefinitely? Can my DNA'd cattle that are no longer alive be used to increase the EPD accuracy on my cattle today?
  22. In theory yes, but it depends. Firstly, if there's enough hair/DNA stored at the lab from the previous submissions and that sample is still viable (not degraded) you could opt to genotype those animals. Secondly, GE-EPD testing on an older animal that has many data recorded progeny may not increase the accuracy of the evaluation to the same extent as compared to the accuracy increase that will be seen on a young animal with limited data. If the older animal in question over its lifetime had limited progeny data entered, then yes, a High Density SNP test to generate GE-EPDs on that older animal will have a positive effect on the accuracies of its progeny.

  23. How do you match dam and possible sire EPDs to know if they will be a good match?
  24. Firstly, start off with a goal in mind. What are your breeding goals for your herd; "good" mating is relative to what the goals of your breeding program are. Once you have your goal EPDs, the easiest way to estimate the outcome of any mating is take half the Sires EPD trait value and half the Dams EPD trait value and add them together for an estimate of the progeny's EPDs . Since GE-EPDs and EPDs are interpreted the same, you can do this with EPDs and GE-EPDs or any combination of the two. Also, take the time to sit down and calculate the average EPD for each trait over your entire your cow herd; if you ensure that your breeding goals are met on your entire herd (opposed to individual mating) the average cow in your herd will better meet your goals over time; and your elite females will do the same.

  25. How do you determine EPD's on cattle that have no sire or dam EPD information?
  26. Once an animal that doesn't have any EPDs has a calf and that calf is born within a group that's robust enough to be considered to be a contemporary group and data on that calf is submitted for analysis, EPDs will being to be generated based on the progeny's performance.

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