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EPD Basics

horseless:

Creep feeding a group of calves does not affect the EPD of the group. Breed associations do ask that creep feeding is reported to them.

They all get the treatment, the group average weight goes up, but the EPD are still going to be the same average as if they weren't creep-fed. I suppose if you had a big mix of high and low growth cattle in the group, it would spread the EPD out more, though. But, most breeders don't really mix wideranging EPD too much.

Now, if an individual animal really pigs out relative to some others, then that animal would have an inflated WW EPD relative to the group, same as if an animal didn't like to eat creep. GT MAximum spent a lot of time in the creep feeder, but guess what? His EPD were pretty high powered for the time. He was a big bull, who needed to eat a lot to grow, but he also transmitted that growth to his progeny.

If someone creep fed a group of calves and then reported them to be in the same contemporary group as non creep-fed calves, then the EPD would be wacky.

But, any treatment that applies to all the calves in the group has no effect on boosting or depressing EPD. The treatment becomes part of the contemporary group definition, thus it can't cause a shift in EPD.

Badlands
 
If some EPD numbers catch my eye, I do further research. I look at the accuracy figures, then go deeper and look at the number of offspring, contemporaries, and to me the most important, THE NUMBER OF HERDS.

There was a heavily pushed bull about 15 years ago that turned into a milk disaster. It wasn't until you got deep into his Angus performance pedigree that you discovered he was used in only 2 neighboring herds for two years to get those numbers. When he was used in the general population, the true EPDs were expressed and his true value came out. In this case, EPDs and a larger group of contemporaries exposed the padded numbers, it just took two more years to show up, and hurt a lot of cattle producers in the meantime. A sire analyst got an education on that one and is continuing his education at a different location.
 
Badlands said:
lazy ace:

Jason hit it right here, "The actual weight differences means the ratio would be higher or lower on the groups of calves.

The amount the ratio is higher or lower is not what is measured, it is the actual pounds."

We talk about ratios because that is how we have done things traditionally, we do it by convention. What BLUP procedures use however, it the adjusted weights.

In the case of your animals, it considers the performance of the dams too. Plus all the other relationships. It is not something you can do in your head, trust me. Maybe for one year, but you can't dynamically handle all the effects over time of having different sires and dams in different groups over several years. Now, that isn't and insult at all. Nobody does this sort of math in their heads, that's all.

Your numbers might be looking a little odd to you, but part of how the EPD end up where they do is from the "competition" in the contemporary group. In other words, what other sires were in there?

I can see that in the case of the dams they did not originate in the same contemporary group, so they had different sire and dam competition within those groups resulting in differing EPD.

ONe thing to remember too, is that we never get enough progeny on most cows to get much accuracy, so they are pretty much stuck with their Interim EPD for life. If they were born with a high BW, but transmit low BW, they EPD will seldom change enough to truly reflect that.

Some call it a flaw in the system, but it's simply a numbers game, and cows don't raise enough calves to move their interims too much. It is odd to hear people argue for cows having EPD that should be able to change, while saying bulls EPD change too much. On one hand they aregue for more volatility, on the other hand they argue for less, forgetting that the EPD are all pooped out by the same system.

Know your cows, use high accuracy bulls.

Badlands
Click to expand...


Thanks for the explanation. We used this proven sire in 2005 he was born in 2001 his birth weight was a 2.3 with an accuracy of 66. It went up to a 3.3 in 2006 and now it is a 4 with a 87 for accuracy. How much accuracy can we trust.

We bred our cow to this sire because we saw his 3/4 brother and liked him. We saw him bring good money as a yearling and watched him sell in Denver for the second time as a three year old and he brought over 20000. It looks to me that we just might know more about our breeding program than you do. WE DO KNOW OUR COWS, they keep us in business. Big birth weight epd or small birth weight epd he will do all right for us and are commercial customers.

lazy ace
 
Jason said:
TSR what was her backfat scan?

The imf scan is pretty good, but heifers will lay down more marbling. Steers will be slightly less (I don't know the %) under the same conditions and steers are 30% fatter, and about 1% more imf than bulls under the same management.

The other thing is when an animal is smaller the imf numbers will appear greater, but if that animal was fed more, and the ribeye was bigger, would the animal have enough marbling in the bigger area.

That is the reason implants hurt marbling scores, they tend to make ribeyes bigger and to get the same % imf, it takes more fat.

Shrinking frame size has the effect of increasing imf % wise.

Jason, Her Rib fat and Rump fat were both .06.
Click to expand...
 
TSR with that low backfat, her marbling is awesome.

The next thing I found was that the epd of her sire/dam have a lot to do with her epd on marbling.

The heritability on imf is something like .41 as opposed to gain being .81

It takes longer to change the real marbling numbers by using high imf bulls than it does to put feed conversion in.

A while back there was an article that said to move 1 grade score...not select to choice, but modest to modest + (the exact terms elude my mind right now).... it would take 2 generations using the #1 imf bull of the Angus breed.

We are talking about tiny % of marbling fat with epds.

We found our scans were good because we had been stacking carcass bulls in as we could since using epds. It is the depth of the genetics that make for real change.

Your heifer might not get the epd you would like, but keep building. It is a great real world scan, the numbers will follow.
 
http://www.angussiresearch.com/heritabilities.html

Feed conversion? About .25-.35, sometimes up to .40.

On the average, these AAA carcass traits are on the low side, compared to literature values.

Mature traits and carcass traits are generally of high heritability, followed by growth traits, with fertility traits being lowest.

Badlands
 
T99 To find the contemporaries/herds, look at the bottom of the performance pedigree. There beside every epd column there is one labeled as conts/herds. This will go back 3 generations so you can see trends within that line of cattle. This is available in almost all the breeds that are putting out epds.
 
Thanks Mike for starting the thread. Honestly I didnt even know what an EPD was. Haha Half the time if you dont dumb it down I dont know what you and Jason, Northern , etc are argueing about on Ranch Talk.
 
Thanks S Co Rancher. I found it on the pedigrees I have here at home but do you know where I can find this information online? I've been looking at pedigress on the angus website and it's not available there.
 
Jason said:
TSR with that low backfat, her marbling is awesome.

The next thing I found was that the epd of her sire/dam have a lot to do with her epd on marbling.

The heritability on imf is something like .41 as opposed to gain being .81

It takes longer to change the real marbling numbers by using high imf bulls than it does to put feed conversion in.

A while back there was an article that said to move 1 grade score...not select to choice, but modest to modest + (the exact terms elude my mind right now).... it would take 2 generations using the #1 imf bull of the Angus breed.

We are talking about tiny % of marbling fat with epds.

We found our scans were good because we had been stacking carcass bulls in as we could since using epds. It is the depth of the genetics that make for real change.

Your heifer might not get the epd you would like, but keep building. It is a great real world scan, the numbers will follow.
Click to expand...


Jason, you make some very good pionts, but I have to disagree on how hard it is to breed marbling in or out. I have bulls that will never sire a select calf on my cows and I have bulls that will only grade 50% chioce. These are on the same cows. The cows were all scanned as heifers and there is a good corilation to there calves but the bull makes alot more diffrance than one marbling score in two generations.
I do believe that you could use the highest REA bull in the angus breed and only raise your REA 1sq inch in two generations.
 
As a strictly commercial producer, I use epd's to cull out the bulls that I know I don't want to look at. Guess I'm kinda old-fashioned, though - because I still place a lot of emphasis on actual weights. And phenotype. But I think it's foolish for me not to try to use every tool available to me in bull selection. Epd's are just one more thing to help me make a better decision.

Good thread, Mike. Thanks for starting it.
 
"As a strictly commercial producer, I use epd's to cull out the bulls that I know I don't want to look at."

An excellent point, Texan, as a purebred and commercial breeder, I do the same thing.

I am a firm believer in improving cattle by getting rid of what is wrong with them.

Badlands
 
Andy said:
Jason said:
TSR with that low backfat, her marbling is awesome.

The next thing I found was that the epd of her sire/dam have a lot to do with her epd on marbling.

The heritability on imf is something like .41 as opposed to gain being .81

It takes longer to change the real marbling numbers by using high imf bulls than it does to put feed conversion in.

A while back there was an article that said to move 1 grade score...not select to choice, but modest to modest + (the exact terms elude my mind right now).... it would take 2 generations using the #1 imf bull of the Angus breed.

We are talking about tiny % of marbling fat with epds.

We found our scans were good because we had been stacking carcass bulls in as we could since using epds. It is the depth of the genetics that make for real change.

Your heifer might not get the epd you would like, but keep building. It is a great real world scan, the numbers will follow.
Click to expand...


Jason, you make some very good pionts, but I have to disagree on how hard it is to breed marbling in or out. I have bulls that will never sire a select calf on my cows and I have bulls that will only grade 50% chioce. These are on the same cows. The cows were all scanned as heifers and there is a good corilation to there calves but the bull makes alot more diffrance than one marbling score in two generations.
I do believe that you could use the highest REA bull in the angus breed and only raise your REA 1sq inch in two generations.
Click to expand...

That very well could be Andy, but are both bulls Angus? The article I read was based on the actual measurements of imf.

I could believe a sire of 1 breed would sire far less choice calves than a bull from a marbling breed like Angus.

I think Northern said it well when he said to increase marbling(in a crossbreeding system) use the Angus, to improve other things, use a breed noted for that trait.
 
Jason said:
TSR with that low backfat, her marbling is awesome.

The next thing I found was that the epd of her sire/dam have a lot to do with her epd on marbling.

The heritability on imf is something like .41 as opposed to gain being .81

It takes longer to change the real marbling numbers by using high imf bulls than it does to put feed conversion in.

A while back there was an article that said to move 1 grade score...not select to choice, but modest to modest + (the exact terms elude my mind right now).... it would take 2 generations using the #1 imf bull of the Angus breed.

We are talking about tiny % of marbling fat with epds.

We found our scans were good because we had been stacking carcass bulls in as we could since using epds. It is the depth of the genetics that make for real change.

Your heifer might not get the epd you would like, but keep building. It is a great real world scan, the numbers will follow.
Click to expand...

Thanks Jason, I value your opinion. Things are going to get interesting as I have this heifer's full brother to scan in about a month. Although at weaning he did get a little sick on me (pinkeye) and it took a week or so to get him well. But I have been giving him some corn daily(~ 5lbs) with some protein supplement. I am looking forward to see what he does. Good thing is, phenotypically, these are also some of my best cattle. Breeding cattle, I really enjoy it. Its therapy after working all day just going out and seein them.
 
Funny thing about EPD's. I am always hearing how everyone cheats on the data presented to determine them, but never about the bulls/cows who do breed close to the numbers. :???:

There have been more than a few pilot programs where breed associations have encouraged the commercial guys to document the sires in a calf crop and weigh the calves at birth and weaning to prove the validity of EPD's.

But very few wanted to go through the extra "TROUBLE". :mad: Most wanted to be "PAID". :roll:

On two separate occasions I have given a hundred straws of semen to research in this area. Hope it pays off for someone.
 
Mike, I can garantee that good EPDs will breed true. I have seen it in the early days before guys were trying to beat the system.

The system of EPDs will always correct it, but with the troubles, it isn't as easy as it used to be to find the next generation of cattle you want by the numbers.

It is costly to try 5 new sires and be disappointed with 4 of them. It is impossible for a very small breeder to even try new sires with any kind of risk.

The advantage has shifted back to breeders that have the eye and understand the numbers. Hopefully the commercial bull buyers will follow and reward the better breeders instead of the better number guys.
 
There have been more than a few pilot programs where breed associations have encouraged the commercial guys to document the sires in a calf crop and weigh the calves at birth and weaning to prove the validity of EPD's.
Click to expand...

Mike, I'm confused on this statement. What do you mean..... What do you mean by commercial? Commercial to me is when there are no papers or epds to go on... How can a person document anything when there is no bases ( records) on the dams side??

What formula would you use say like on my herefords or on my angus cows since they are both differant.....
 
Katrina, if you were to randomly breed 2 or 3 A.I. sires to your cows on a gate run sort, the EPD's if accurate should show through in bw weaning weight and yearling weight. The difference or similarity of the numbers from the bulls should be apperant, over the average of your cows no matter their origin.

Your best cows should still raise the best calves, but if you haven't selected all your best cows to breed 1 bull and all the worst to breed the other bull to, the results shouls be verifyable.

As for the direction to go with the numbers, you are right, that is a guess based on what numbers the bulls you have bought have, compared to the bulls you buy to improve things they leave behind.
 

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