EPD's

[ollie?]

I think that you are forgetting that the numbers are just AVERAGES. 2 pounds more birth weight does not mean that every calf by bull B is going to be 2 pounds heavier than cakves by bull A it means that bull B typically throws more heavy calves than bull A and we quantify that with the EPD. If you breed them both to a 1000 cows, Bull A will throw some very heavy calves and Bull B will throw some very lite calves. All the EPD is telling you is that you are more likely to get a HEAVY calf with Bull B than with Bull A. The higher the birth weight EPD the greater the risk of a TOO big calf that could cost you a good heifer. Likewise if you pursue the lowest possible birth weight in your breed you are more likely to get some little dinky 55 pound calves that never fully catch up at weaning.

The bw epd doesn't tell you any such thing. It only tells you that bull A's calves will be , on average, 2lbs lighter. It doesn't say which bull will sire more heavy calves .

 

[DOC HARRIS]

SELECT BULL(s) WITH OPTIMAL CALVING EASE AND LOW BIRTH WEIGHT EPD's.
ollie - that is as simple as I can make it!
DOC HARRIS

Doc, you listed 13 things other than epd's that relate to dystocia. I'm aware of all those and a few more. But lets keep our discussion epd based. Since he's never going to buy an older bull that is proven on a heard of registered cows, lets assume that the epd's on any given bull that he will own is low. Since these are virgin bulls that he buys the CE epd will be very heavily loaded with the BW epd of the said individual. It boils down to BW epd on these young virgin bulls , would you agree? If so, we'll further discuss the validity of using BW epd's as a good indicator to avoid dystocia.
Thanks Doc for the discussion.

ollie -

Any further discussion is not really valid, because it will just be repititious. If you disagree - - show me your BETTER option.
Notice the last two sentences relating to the size of the fetus compared to the size of the cow! THAT is the operable situation when questioning the problem of dystocia. There are many other secondary causes - but fetal size and cow size is the workable and feasible factors which must be addressed immediately.

HOW?

Here comes the "EPD" answer! By carefully selecting the Bulls - AND cows - repeat - AND COWS - by ruthlessly observing Calving Ease (CE) AND Birthweight (BW) that EACH individual animal possesses! THAT is the simple answer. There are other inheritance traits and characteristics as well as managerial decisions which enter into the formula as well, as is indicated above, but how to arrive at that solution is through EPD's and study of Phenotype.

ollie - You might "select out" the phrases that your friend might disagree with, and that with which you might not agree. But any further rhetoric on my part will just include the material I have itemized above!

I thought that I answered his pressing question.

DOC HARRIS

 

[dun]

Hmmm - kinda think alike too.

That's scary!

dun

 

[ollie?]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

 

[DOC HARRIS]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

ollie-

;-) But any further rhetoric on my part will just include the material I have itemized above!

DOC HARRIS

 

[dun]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

 

[ollie?]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

which is heavily loaded with bw epd (which we've just discussed how bw epd doesn't predict dystocia) and never receives any accuracy whatsoever on virgin bulls destined for a commercial herd.

 

[Tod Dague]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

which is heavily loaded with bw epd (which we've just discussed how bw epd doesn't predict dystocia) and never receives any accuracy whatsoever on virgin bulls destined for a commercial herd.

If you don't use EPDs you have the bulls performance and his pedigrees' as far back as you have knowledge of. Where as the EPD uses the info that you co have plus the rest of the animals that are related to him across the country. That being said you would be hard pressed to get me to use a bull with a BW of 110 lb on heifers no matter the epds.

 

[ollie?]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

which is heavily loaded with bw epd (which we've just discussed how bw epd doesn't predict dystocia) and never receives any accuracy whatsoever on virgin bulls destined for a commercial herd.

If you don't use EPDs you have the bulls performance and his pedigrees' as far back as you have knowledge of. Where as the EPD uses the info that you co have plus the rest of the animals that are related to him across the country. That being said you would be hard pressed to get me to use a bull with a BW of 110 lb on heifers no matter the epds.

But any knowledge I might have would also include knowledge about predictability of the calf size range , and any known dystocia.

 

[Tod Dague]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

which is heavily loaded with bw epd (which we've just discussed how bw epd doesn't predict dystocia) and never receives any accuracy whatsoever on virgin bulls destined for a commercial herd.

If you don't use EPDs you have the bulls performance and his pedigrees' as far back as you have knowledge of. Where as the EPD uses the info that you co have plus the rest of the animals that are related to him across the country. That being said you would be hard pressed to get me to use a bull with a BW of 110 lb on heifers no matter the epds.

But any knowledge I might have would also include knowledge about predictability of the calf size range , and any known dystocia.

Calf size range is of little concern when you have the dystocia info which is included in the CED epd. Because what is truly important is getting a live calf not a calf of a certain size.

 

[ollie?]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

which is heavily loaded with bw epd (which we've just discussed how bw epd doesn't predict dystocia) and never receives any accuracy whatsoever on virgin bulls destined for a commercial herd.

If you don't use EPDs you have the bulls performance and his pedigrees' as far back as you have knowledge of. Where as the EPD uses the info that you co have plus the rest of the animals that are related to him across the country. That being said you would be hard pressed to get me to use a bull with a BW of 110 lb on heifers no matter the epds.

But any knowledge I might have would also include knowledge about predictability of the calf size range , and any known dystocia.

Calf size range is of little concern when you have the dystocia info which is included in the CED epd. Because what is truly important is getting a live calf not a calf of a certain size.

I'd certainly agree with that Tod. Do you think that the CED on virgin bulls is accurate?

 

[Tod Dague]

Doc, I'm not trying to play word games. BW epd only shows the difference between two bulls calves bw on average.

It says nothing about dystocia and doesn't say which bull will sire calves that are outliers for heavy BW.

It's possible, quite possible that a bull with a lower bw epd can sire a wider range of bw in his calves thus siring calves way outside the tolerable bw range , both heavier and lighter , yet still have a lower bw epd because on average his calves are smaller. A different bull when compared to the previous mentioned bull, might sire a more consistant set of calves that average 4lbs heavier at birth but you don't get as many lights or heavies thus, less dystocia.

Which is what the CE EPD address'

dun

which is heavily loaded with bw epd (which we've just discussed how bw epd doesn't predict dystocia) and never receives any accuracy whatsoever on virgin bulls destined for a commercial herd.

If you don't use EPDs you have the bulls performance and his pedigrees' as far back as you have knowledge of. Where as the EPD uses the info that you co have plus the rest of the animals that are related to him across the country. That being said you would be hard pressed to get me to use a bull with a BW of 110 lb on heifers no matter the epds.

But any knowledge I might have would also include knowledge about predictability of the calf size range , and any known dystocia.

Calf size range is of little concern when you have the dystocia info which is included in the CED epd. Because what is truly important is getting a live calf not a calf of a certain size.

I'd certainly agree with that Tod. Do you think that the CED on virgin bulls is accurate?

I think it is fairly accurate but like I said before "you would be hard pressed to get me to use a bull with a BW of 110 lb on heifers no matter the epds." You have to use some common sense.

My yearling bulls typically have an acc value of .20. The RAA states a possible change of +/- 7 on bulls with that acc. Which can be fairly significant.

 

[ollie?]

Both bulls of mine that you are aware of are a 4 for CED. You know enough about both bulls to know they are very different type bulls when it comes to calving. Both acc. are low (.27) and I don't think they reveal much about either bull. Do you?

 

[Tod Dague]

Both bulls of mine that you are aware of are a 4 for CED. You know enough about both bulls to know they are very different type bulls when it comes to calving. Both acc. are low (.27) and I don't think they reveal much about either bull. Do you?

You got me there! :lol: :lol: :lol: That's where the common sense comes in. :lol:

 

[ollie?]

:lol:

 

[Brandonm2]

I think that you are forgetting that the numbers are just AVERAGES. 2 pounds more birth weight does not mean that every calf by bull B is going to be 2 pounds heavier than cakves by bull A it means that bull B typically throws more heavy calves than bull A and we quantify that with the EPD. If you breed them both to a 1000 cows, Bull A will throw some very heavy calves and Bull B will throw some very lite calves. All the EPD is telling you is that you are more likely to get a HEAVY calf with Bull B than with Bull A. The higher the birth weight EPD the greater the risk of a TOO big calf that could cost you a good heifer. Likewise if you pursue the lowest possible birth weight in your breed you are more likely to get some little dinky 55 pound calves that never fully catch up at weaning.

The bw epd doesn't tell you any such thing. It only tells you that bull A's calves will be , on average, 2lbs lighter. It doesn't say which bull will sire more heavy calves .

Let's try this again. How does a bull get a higher average? ...... Across the board, MORE of his calves are on the heavy side than a bull with an EPD of 2 pounds less. It is called an A V E R A G E. I did not say that bull B is a cow killer who will have more 100++ pound calves than bull A. It is quite possible and the data tends to support that supposition; but we do not know THAT; but that high birth weight EPD does tell me LOUDLY that his calves tend to be on the heavy side for the breed which makes him a greater risk. Some people will CLAIM that some high birth weight bulls have a tighter spread than some better birth weight bulls. That is entirely possible; but unless I have seen the actual data myself I would be skeptical of any such undocumented claims especially if it were the bull's owner feeding me that line.

I do not see why this dilema is a problem at ALL. In any of the major breeds there are literally hundreds of sires living or dead out there I can buy semen from. There will be THOUSANDS of registered boy bulls marketed in the next 12 months thru sales or by private treaty. If a bull's birth weight EPD does not fall within the acceptable range for the goals you have for your herd, you simply do not use that bull. You pick another one who IS more acceptable. If you use "Bull A" and are not pleased with his calves go find Bull C, don't spend every waking hour trying to defend Bull B if both his birth weight and calving ease numbers are both unacceptable. There is ALWAYS a better bull out there.

 

[ollie?]

I think that you are forgetting that the numbers are just AVERAGES. 2 pounds more birth weight does not mean that every calf by bull B is going to be 2 pounds heavier than cakves by bull A it means that bull B typically throws more heavy calves than bull A and we quantify that with the EPD. If you breed them both to a 1000 cows, Bull A will throw some very heavy calves and Bull B will throw some very lite calves. All the EPD is telling you is that you are more likely to get a HEAVY calf with Bull B than with Bull A. The higher the birth weight EPD the greater the risk of a TOO big calf that could cost you a good heifer. Likewise if you pursue the lowest possible birth weight in your breed you are more likely to get some little dinky 55 pound calves that never fully catch up at weaning.

The bw epd doesn't tell you any such thing. It only tells you that bull A's calves will be , on average, 2lbs lighter. It doesn't say which bull will sire more heavy calves .

Let's try this again. How does a bull get a higher average? ...... Across the board, MORE of his calves are on the heavy side than a bull with an EPD of 2 pounds less. .

Hey, congratulations , you got it right this time. It doesn't say bull A or bull B will sire calves very heavy or very light does it. You keep studying those epd's brandon and some day you'll have them figured out.

 

[MikeC]

Questionable Ollie wrote: But any knowledge I might have would also include knowledge about predictability of the calf size range , and any known dystocia.

I have no idea how other breed associations collect calving data, but. We turn in calf BW and a score of the assistance given during parturition, if any, grades 1-9.

The main point of EPD's is the collection of data on these traits. If every breeder turns in the data required, then it would be much more complete than an individual breeder, like you say, you "might" include knowledge about.............

EPD's are the best estimate of breeding potential that we have. Especially when most every producer is collecting the same data each year and the association has a way of using it throughout the entire herd.

There is no one that will argue that EPD's don't have their shortcomings, but there is no way you can collect all this data for yourself on the entire North American herd.

Do you have a better way of assimilating the data for predicting genetic potential?

I understand that young virgin bulls don't have the accuracy that some might require, but how would you gather that data if they are virgins? Would you rather have no data?

Traits are inheritable, to a certain degree. Epd's are based on this and this alone. You might be expecting more from EPD's than can be possible given they are not 100% heritable.

No two people look at cattle alike either. So that throws phenotypical evaluation across the whole herd out the window too.

How else would you predict genetic potential?

 

[ollie?]

Questionable Ollie wrote: But any knowledge I might have would also include knowledge about predictability of the calf size range , and any known dystocia.

I have no idea how other breed associations collect calving data, but. We turn in calf BW and a score of the assistance given during parturition, if any, grades 1-9.

The main point of EPD's is the collection of data on these traits. If every breeder turns in the data required, then it would be much more complete than an individual breeder, like you say, you "might" include knowledge about.............

EPD's are the best estimate of breeding potential that we have. Especially when most every producer is collecting the same data each year and the association has a way of using it throughout the entire herd.

There is no one that will argue that EPD's don't have their shortcomings, but there is no way you can collect all this data for yourself on the entire North American herd.

Do you have a better way of assimilating the data for predicting genetic potential?

I understand that young virgin bulls don't have the accuracy that some might require, but how would you gather that data if they are virgins? Would you rather have no data?

Traits are inheritable, to a certain degree. Epd's are based on this and this alone. You might be expecting more from EPD's than can be possible given they are not 100% heritable.

No two people look at cattle alike either. So that throws phenotypical evaluation across the whole herd out the window too.

How else would you predict genetic potential?

Mike I've done alright breeding cattle. My point though wasn't to prove my way is better. I merely took exception with the statement that said something like (paraphrasing and exaggerating) if you care about your product and have half a brain, you'll be using epd's to make your decisions.

 

[MikeC]

I understand.

I think that EPD's are somewhat overused to a degree also, but the data collection portion of it is it's main function.

Putting that data into an easily understood numerical score is to me pretty amazing.