EPD's, reading the chart correctly.

[Txwalt]

http://www.ars.usda.gov/sp2UserFiles/Pl ... 06News.pdf

So if we took a Charolais bull and put it with a Brangus cow. We would have a 4.8lb increase in BW. Lets pretend the bull and cow in the example have the EPD's exactly like the chart. Likewise the WW would increase by 18.9 pounds. Is this right?

Let me change the subject slightly. Since heterosis starts before birth, if we have F1 cows and put a different breed of bull in the mix for a 3 way cross wouldn't the risk of calving issues go up considerably?

More questions to follow once I see where this is going.

Walt

 

[MikeC]

For comparison of bulls from different breeds.

Has nothing to do with the cow.

Certainly has nothing to do with predicting BW's, or WW's.

Yes heterosis does start before birth. It's calculated in this chart.

But you have no idea of the BW EPD's of the cows, so there is really no way you can add in the cow equation.

 

[Frankie]

http://www.ars.usda.gov/sp2UserFiles/Place/54380000/GPE/AB_EPD2006News.pdf

So if we took a Charolais bull and put it with a Brangus cow. We would have a 4.8lb increase in BW. Lets pretend the bull and cow in the example have the EPD's exactly like the chart. Likewise the WW would increase by 18.9 pounds. Is this right?

Let me change the subject slightly. Since heterosis starts before birth, if we have F1 cows and put a different breed of bull in the mix for a 3 way cross wouldn't the risk of calving issues go up considerably?

More questions to follow once I see where this is going.

Walt

I don't think so. The across breed EPD chart is set up to compare bulls across breeds.

If we use breed average EPDs (from my ABS catalog), this is how I think they're supposed to be used:

Average EPDs for Chars:

BW EPD 1.2, WW, 22, YW 39. We add those adjustments to the figures and get:

BW EPD of 11, WW 61 and YW of 92 for Charolais.

Average EPDs for Angus, from the same catalog are:

BW EPD 2.3, WW 39, and YW 73. Since there are no adjustment factors, you would compare those numbers to compare the bulls.

Obviously not all bulls of any breed will have average EPDs. Some will have higher, some lower. You'll add the same adjustment factors to their EPDs to compare them.

This is supposed to give you the tools to compare EPDs of bulls of different breeds.

Someone correct me if I'm wrong.

 

[MikeC]

You're right.

 

[dun]

The BW deal bringiing in Heterosis is exactly thwy I wish the RA Asociaiton, Brangys Associationm Nalf and who ever the others are that are involved in the standard EPDs that are being worked on. Those are supposed to address Heterosis as part of the standards.

 

[WORANCH]

The BW deal bringiing in Heterosis is exactly thwy I wish the RA Asociaiton, Brangys Associationm Nalf and who ever the others are that are involved in the standard EPDs that are being worked on. Those are supposed to address Heterosis as part of the standards.

Maybe you have been out in the heat to long also.

 

[Txwalt]

For comparison of bulls from different breeds.

Has nothing to do with the cow.

Certainly has nothing to do with predicting BW's, or WW's.

Yes heterosis does start before birth. It's calculated in this chart.

But you have no idea of the BW EPD's of the cows, so there is really no way you can add in the cow equation.

If it has nothing to do with predicting BW's and WW's then what would the purpose of the chart be? Certainly Bulls mounting Bulls will not produce calves. I thought these #'s were generated from the bulls progeny or projected progeny based on his parents. Wouldn't that mean the #'s are generated from the average production from the cows?

Walt

 

[MikeC]

For comparison of bulls from different breeds.

Has nothing to do with the cow.

Certainly has nothing to do with predicting BW's, or WW's.

Yes heterosis does start before birth. It's calculated in this chart.

But you have no idea of the BW EPD's of the cows, so there is really no way you can add in the cow equation.

If it has nothing to do with predicting BW's and WW's then what would the purpose of the chart be? Certainly Bulls mounting Bulls will not produce calves. I thought these #'s were generated from the bulls progeny or projected progeny based on his parents. Wouldn't that mean the #'s are generated from the average production from the cows?

Walt

It has nothing to do with predicting the "Actual Weights" of the calves. It may give an idea of the "Difference" in calf weights though, but I have my doubts as to how accurate they would be.

The chart is for comparing bulls of different breeds.

Since most commercial cows do not have EPD's, theirs could not come into play when calculating calf weights anyway.

I really don't know why the chart would be used by anyone for any reason. Commercial cows could be so diverse in characteristics that it seems this chart is a waste of time.

I guess it's just a guideline??????????????????????

It's hard enough mating two registered animals with loads of data on them both. JMHO

Sorry I didn't make myself clear the first time...............

 

[Frankie]

For comparison of bulls from different breeds.

Has nothing to do with the cow.

Certainly has nothing to do with predicting BW's, or WW's.

Yes heterosis does start before birth. It's calculated in this chart.

But you have no idea of the BW EPD's of the cows, so there is really no way you can add in the cow equation.

If it has nothing to do with predicting BW's and WW's then what would the purpose of the chart be? Certainly Bulls mounting Bulls will not produce calves. I thought these #'s were generated from the bulls progeny or projected progeny based on his parents. Wouldn't that mean the #'s are generated from the average production from the cows?

Walt

EPDs are used to compare breeding stock, usually bulls. This chart is set up to compare bulls from different breeds.

EPDs will never tell you what a calf will weigh at any time. They just allow you to say, if I use a bull with a BW EPD of 5, I can expect my calves to weigh 5 more pounds at birth than if I used a bull with a BW EPD of 0. (If we're talking about bulls within the same breed and not this across breed stuff.) The cows, management, climate, all those things have an influence on the calf's weight. EPDs will never be able to take those into account. But you have the cows, you have a climate, you have pasture, feed, management. EPDs allow you to compare bulls andl tell you which bull is likely to give you heavier (or lighter) calves at birth, weaning, yearling, etc., under that system.

 

[Txwalt]

Thanks guys. I think I finally got it through my thick noggen.

Walt

 

[Frankie]

Thanks guys. I think I finally got it through my thick noggen.

Walt

You're welcome.