EPD's What Do They Mean?

[Frankie]

Plus EPDs take environment and management out of the equation so that a bull that's creep fed won't have better EPDs than a bull that's not.

the only problem with this is when people take creep feeding to the next level. some places boasting 1000+ weaning weights have to be feeding some hot feed to get those weights. many of these bulls have WW EPDs higher than either of their parents.

But since EPDs are based on contemporary groups, it shouldn't matter. A good bull's calf will stand our in a creep fed group; a good bull's calf will stand out on grass. The evaluations are made from contemporary groups, not single animals. If you report information on a single animal, without a contemporary group, that data isn't used to create EPDs.

We all have seen high EPDs crash when a bull get's widely used. That's why I'd never take a chance on breeding heifers to a bull without high BW EPD accuracies. It's one thing to be disappointed in the growth of a calf; it's another to lose a calf or heifer because of calving problems. I'm very grateful to those people who do use unproven bulls so I can be choosey about which I use.

 

[Aero]

There is NO ADJUSTMENT in the 205 Day Wt based on CREEP. They are adjusted by number of days old, and by age of dam. The creep info goes into the data base to be used to adjust the figures in the EPDs.

i know what you are saying, but it seemed a little contradictory.

 

[norriscathy]

Getting some good info from the AAA. THe standard deviation of Angus EPD's is 2.4 # for BW; 17 # for WW; and 32 # for yearling weight. "Accuracy" is something unto itself; closely akin to statistical probably but not as precise. They are sending me more info, graphs, tables, etc. Very helpful, will let yall know when info is received. They told me that with a .30 accuracy for weaning weight, 2/3 of the animals would be within 8.1 # for a given WW EPD.

 

[Angus Guy]

Jeanne

After some 20 odd years watching and using epd's I will stand by my statement that the BW does not hold true. This does not mean if I have a choice between a low BW and high BW. I will take the low bull if they are equal otherwise. By the same token what hasn't been mention is the cows epd's. This is 1/2 of your calf.

 

[Aero]

By the same token what hasn't been mention is the cows epd's. This is 1/2 of your calf.

when most accuracies are 0.30 and below, its hard to put much weight into it. compared to a bull with a 0.90 Acc, the cow is almost an unknown.

dont get me wrong, i use the cow's EPDs since low acc is way better than no acc.

 

[Angus Guy]

Aero
I'll agree with that. We just need to find some way of getting the cow #'s to track better.

 

[norriscathy]

AAA statistician told me that "people expect this to be a science and it is not". Waiting on more data from AAA. I agree Angus Guy, after using EPD's for thirty years they should only be used as a "tie breaker" unless you're talking about a 90%+ accuracy level.

 

[SEC]

I think EPD's are interesting as it takes in every kind of difference possible in the climate, grass whatever you name it, it's accounted for. To some point the EPD's work and then ( I am not sure of what level) it seems like things go a little crazy. Like EPD's over 100 for YW. I am usually spooked and become leary with bulls with astronomical bwts. Krugerrand 410H is a bull that has held close to his numbers, yet doesn't appear to calve quite as light as his EPD's show nor do his calves blow away the progeny either. The Hyline Right Way calves from our herd and others haven't been high at all and yet the bulls bwt EPD jumped like 2.2 lbs on his bwt.

The only EPD's I really follow is milk, scrotal and I avoid the extreme marbling cattle. In fact, I generally avoid extreme EPD cattle completely.

 

[Frankie]

Jeanne

After some 20 odd years watching and using epd's I will stand by my statement that the BW does not hold true. This does not mean if I have a choice between a low BW and high BW. I will take the low bull if they are equal otherwise. By the same token what hasn't been mention is the cows epd's. This is 1/2 of your calf.

But EPDs are only used to compare animals. The bull's EPDs only reflect his genetic merit. As you say, they can't take the cow's genes into account. If his BW EPD is 5, you can EXPECT his calves to weigh 5 more pounds at birth than if you bred those same cows under the same conditions to a bull with a BW EPD of 0. But EPS will never ever tell you what something will weigh because they can't take into account the cow or management. So what makes you think BW EPDs aren't accruate, in general?

 

[lakading]

Jeanne

After some 20 odd years watching and using epd's I will stand by my statement that the BW does not hold true. This does not mean if I have a choice between a low BW and high BW. I will take the low bull if they are equal otherwise. By the same token what hasn't been mention is the cows epd's. This is 1/2 of your calf.

But EPDs are only used to compare animals. The bull's EPDs only reflect his genetic merit. As you say, they can't take the cow's genes into account. If his BW EPD is 5, you can EXPECT his calves to weigh 5 more pounds at birth than if you bred those same cows under the same conditions to a bull with a BW EPD of 0. But EPS will never ever tell you what something will weigh because they can't take into account the cow or management. So what makes you think BW EPDs aren't accruate, in general?

Well said, Frankie.

 

[ollie']

Do any epd supporters believe phenotype of the actual animal play a roll in the animals actual preformance. For example does a bigger volumed calf utilize available feed more efficiently?

 

[MikeC]

Do any epd supporters believe phenotype of the actual animal play a roll in the animals actual preformance. For example does a bigger volumed calf utilize available feed more efficiently?

I absolutely believe that phenotype plays a big roll in actual performance. Problem is....Epd's and Phenotype are two entirely different matters. Each must be considered on their own merit.


The big question I have is......Why is the YW and the MILK EPD so antagonistic? Any thoughts?

 

[Angus Guy]

Frankie

This my observations with many different herds that I have selected bulls and heifers for. It has also been observed in my own herd of reg. and comm. cows. All of these observations are with herds that at minium either weigh or tape their calves at birth. BW is the only epd that I don't always agree with.

 

[ollie']

Do any epd supporters believe phenotype of the actual animal play a roll in the animals actual preformance. For example does a bigger volumed calf utilize available feed more efficiently?

I absolutely believe that phenotype plays a big roll in actual performance. Problem is....Epd's and Phenotype are two entirely different matters. Each must be considered on their own merit.


The big question I have is......Why is the YW and the MILK EPD so antagonistic? Any thoughts?

I know you Mike and we think alike but for the sake of argument how do you reconcile the fact that a bull which is bigger volumed but has a lower ww epd actually could be the better choice for heavier weaning weights in a low input environment? It takes more energy for the large framed tighter made calves to maintain their self so they don't have much energy left to grow , conversley in a low input environment a smaller framed calf with more volume takes less energy to maintain himself has more energy left to use for growth. Is that possible ? I am editing because I think you are going to agree with the thought I put forth. If you believe as I do that the above is true are there cattle available out there that are moderate framed but longer , deeper , thicker , with acceptable CE that would be a crossover type bull ? One that would work in a high energy environment because of his total mass but would also work because of his volume and moderate frame in a low input environment as well?

 

[MikeC]

Let me think about the answer I want on that one Ollie. I'll get with you later on it! ;-)

 

[Texan]

I know you Mike and we think alike....

Sorry to hear that, Mike. :lol2:

 

[MikeC]

But Ollie, if that lower WW bull were to sire calves that were heavier, his WW EPD's would go up to show his genetic potential no matter what his FS was.

Then he would no longer be a "Low WW EPD" bull.

 

[ollie']

That is true Mike unless the data was mostly (or entirely) collected in a lush environment. If that were the case then the little bulls ww epd's would go down , even though he might work better most of the time in some locations...??? Make sense?

 

[MikeC]

That is true Mike unless the data was mostly (or entirely) collected in a lush environment. If that were the case then the little bulls ww epd's would go down , even though he might work better most of the time in some locations...??? Make sense?

Since the data collected is based on contemporary groups and a formula is built into the equation (or model) to eliminate environment, I can't see where it would make a difference where the bull is located.

I think what you need to know is how the "Environment Factor" is used in the calculation. I will speak to Robert Williams at the Char Assoc. next week and see if he can explain exactly how that works and will relay it to you. Deal?

 

[la4angus]

I think what you need to know is how the "Environment Factor" is used in the calculation. I will speak to Robert Williams at the Char Assoc. next week and see if he can explain exactly how that works and will relay it to you. Deal?

Heck, relay it to all of us.