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EPD's are BS

Posted: Sat Aug 12, 2017 8:15 pm
by Midtenn
I don't know if that's true, but i got your attention. Case in point.....VAR Generation 2100, considered a high accuracy sire....right now His milk is 20 at .41 accuracy. I looked back at the spring catalogue and he was 44 at .27 accuracy. Can someone explain to me how that is even possible?
He is just one of hundreds of examples you could name of numbers changing drastically.

Another example is this yearling bull here at the house. He weighed 69# at birth and his epd was ced 6 and bw 1.0. DNA test brought his ww number down but bw and ced stayed steady. then after i turned in actual ww his numbers changed drastically to ced 0 and bw 3.0. No ancestor in his bloodline was ever over 2.0 bw. I think I'm going to ignore the numbers and use him on heifers come December.
But what really bothers me, one of his contemporary who was basically same actual bw and ww. I sold him to a customer who specifically did not want "little bitty" calves. His ced was like 9 and bw was like +.8. A week after the sale his numbers went to ced 15 and bw -2.0. I told the customer about the number change and offered to let him trade for a different bull. I just hope he ends up with some nice healthy 85 pounders.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 8:21 pm
by talltimber
LOL Good click bait title! I had to look.

This reminds me of what my neighbor said to me once. "Do you ever wonder why the guys selling low bw bulls never have a calf over 70 pounds?", and "I bet if you look around, you can find some October born fair calves on the ground right now" (this was in August)
I don't know how they change going through an Assoc like that, but the rest is pretty easy to understand how that works.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 9:22 pm
by Bright Raven
Some of the anomalies you mention are a function of a paucity of data. In statistics (that is all EPDs are is statistics based on data points), if there are too few data points it accentuates the extremes. As data points increase so does accuracy. In the first couple years, a bulls numbers have the potential of reflecting extremes. As data accumulates, those extremes mellow out. Statistics is a fascinating study. It is amazing the difference between say 10 data points and 100.

I would not accept your assertion that EPDs are BS. On the other hand, they are not absolutes, they are statistics.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 9:33 pm
by Chocolate Cow
The Angus Assoc recently revised their EPD system to something called "One Step". It made a lot of changes in a lot of animals. It's touted as having greater accuracy.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 9:37 pm
by Bright Raven
Chocolate Cow wrote:The Angus Assoc recently revised their EPD system to something called "One Step". It made a lot of changes in a lot of animals. It's touted as having greater accuracy.


Do you know the mechanics of how it collects and reports data?

Re: EPD's are BS

Posted: Sat Aug 12, 2017 10:04 pm
by Chocolate Cow
Bright Raven, I've been told this article explains One Step very well. I haven't taken time to read it. There are just a few EPD's I consider worth looking at and the type of Angus I prefer, The Association doesn't treat them well anyway.
https://wlj.net/article-permalink-14428.html

Re: EPD's are BS

Posted: Sat Aug 12, 2017 10:17 pm
by Bright Raven
Chocolate Cow wrote:Bright Raven, I've been told this article explains One Step very well. I haven't taken time to read it. There are just a few EPD's I consider worth looking at and the type of Angus I prefer, The Association doesn't treat them well anyway.
https://wlj.net/article-permalink-14428.html


Interesting. Thanks. Made me aware of how much modeling and statistical equations are involved. Relating EPDs to DNA markers really increases the value of EPDs, iMO.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 10:32 pm
by Chocolate Cow
You're welcome.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 10:50 pm
by boondocks
Chocolate Cow wrote:The Angus Assoc recently revised their EPD system to something called "One Step". It made a lot of changes in a lot of animals. It's touted as having greater accuracy.


I don't know if it's a function of that or not, but when we were recently picking Angus AI sires from the Select Sires catalog, I went online to see updated EPDs. They had changed far more drastically than in prior years, since the catalog was mailed just a few months' earlier. Almost all had "worse" EPDs than before. In some cases, the changes were startling.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 11:12 pm
by Chocolate Cow
In my not-worth-much opinion....EPD's were in their own race to the sky. The $Beef, Milk, Weaning numbers were rocketing to some incredibly lofty highs. I wondered how, when or if they would rein it in. Try to slow the hyper number race down. Maybe this is their answer? I really struggle with giving much credibility to EPD's. CED, milk and $EN are the ones I utilize. Interestingly, $EN is the one most breeders would like to do away with.

Re: EPD's are BS

Posted: Sat Aug 12, 2017 11:34 pm
by Son of Butch
A top 10% bull is still a top 10% bull epds are for comparing individuals to each other or vs breed average use the
% ranking. $W and $B are also affected by the drop in beef prices vs year ago or whenever your bull book was published.

Re: EPD's are BS

Posted: Sun Aug 13, 2017 10:47 am
by Midtenn
Chocolate Cow wrote:In my not-worth-much opinion....EPD's were in their own race to the sky. The $Beef, Milk, Weaning numbers were rocketing to some incredibly lofty highs. I wondered how, when or if they would rein it in. Try to slow the hyper number race down. Maybe this is their answer? I really struggle with giving much credibility to EPD's. CED, milk and $EN are the ones I utilize. Interestingly, $EN is the one most breeders would like to do away with.


Until now, I also put a lot of emphasis on milk,EN, and CEM.....but with the example i used of VAR Generation, a so-called high accuracy bull, who's milk just moved 24 points overnight.....what's the use selecting sires based on numbers if they can move from top 10% to bottom10% before your semen arrives?

Re: EPD's are BS

Posted: Sun Aug 13, 2017 11:00 am
by Midtenn
Son of Butch wrote:A top 10% bull is still a top 10% bull epds are for comparing individuals to each other or vs breed average use the
% ranking. $W and $B are also affected by the drop in beef prices vs year ago or whenever your bull book was published.


Incorrect statement you put there. The top 10% milk bull I mentioned "VAR generation"' , is no longer a top 10% bull. I'm not talking about dollar values at all. A pound of milk weighs the same every year ....a pound.
I would have never considered using this bull last spring, but now he's at the top of my list, a list in which I have very little confidence...

Re: EPD's are BS

Posted: Sun Aug 13, 2017 11:19 am
by GN+
https://www.angus.org/Nce/Accuracy.aspx

Pretty interesting table from the angus association that explains the possible deviation from EPD's at different accuracies

Re: EPD's are BS

Posted: Sun Aug 13, 2017 11:52 am
by Midtenn
GN+ wrote:https://www.angus.org/Nce/Accuracy.aspx

Pretty interesting table from the angus association that explains the possible deviation from EPD's at different accuracies

Thanks for showing that. It reminded me that one third of the time, epd numbers can mean absolutely nothing, regardless of accuracy levels.