Calculating Epd's

How do you calculate Epd's for a calf?

This book explains it...



Those formulas on the cover are not giberish, they're part of the process.

You can simplify the process but you'll need a solid mathematical background just to get through the first chapter of that book.

If you want to better understand how EPDs are calculated, and how to use them in genetic improvement, this book would probably be more helpful.  It's an excellent reference, and quite readable.  It takes an advanced statistician to get through Mrode.

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Jeff is correct that the formulas used to calculate epds are quite complicated and far beyond most people.  However, for a calf that has two parents registered with the same breed association a pedigree estimate of its epd for any trait can be obtained by taking half of the sire's epd and adding it to half of the dam's epd.  In many cases this is how the association will calculate initial epds before any performance information is obtained.  Remember though for this to work both parents must be registered with the same association.

Ok well this makes it sounds like its out of my range to calculate them. So I will ask for this advice....I will be taking some heifers to the Nebraska Cattlemans Classic this spring to sell, I feel like I need to provide EPD's for potential buyers. Do you agree?

EPDs are obtained from your breed association.  You should have received a report (Interim EPDs) when you submitted weaning weights.  Most breeds update their EPDs in December, so new numbers will be available in January.  You can look up the heifers' EPDs on most breed associations' websites.

Hope this helps,

Prof

Since you are located in Nebraska, a good person to answer your questions would be Dr. Matt Spangler at the University of Nebraska-Lincoln.  Dr. Spangler is an extension specialist with expertise in beef cattle genetics. His contact information can be found here:

http://animalscience.unl.edu/anscmattspangler

If you won't be able to wait for the EPDs to be calculated by the breed association use the average of them mentioned above and call it "estimated EPDs". 

Thanks for the help!

Jeff_Schroeder said:

If you won't be able to wait for the EPDs to be calculated by the breed association use the average of them mentioned above and call it "estimated EPDs". 

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Hate to be "that guy", but EPD's and EBV's are all estimates. You never really know what an animal is going to pass onto its offspring. I'm all for using EPD's, but as a guideline rather than something to rely on for future calves. I understand what you are getting at Jeff and that its term used, but just catches my attention when someone says "estimated" EPDs.

You're right.  

(it would also be hypocritical of me to get upset with somebody 'that guy'ing me)