Huh? Comments, please

[ollie]

This is ironic and contrary to what I would think of using actual data. Actual data I would think would be the reverse. A good bull should preform even better on a good set of cows.

i disagree. i think it's always easier (whether using epd's or actual data) to improve your bottom enders by using a good bull than to improve your good cows.

 

[ollie]

This is ironic and contrary to what I would think of using actual data. Actual data I would think would be the reverse. A good bull should preform even better on a good set of cows.

i disagree. i think it's always easier (whether using epd's or actual data) to improve your bottom enders by using a good bull than to improve your good cows.

Do you also think on a good set of cows there isn't much difference between a good bull and a lesser one?

 

[txag]

Do you also think on a good set of cows there isn't much difference between a good bull and a lesser one?

nope. did i say that? you should always use the best bull you can find (afford).

 

[ollie]

Do you also think on a good set of cows there isn't much difference between a good bull and a lesser one?

nope. did i say that? you should always use the best bull you can find (afford).

I didn't say you said that . I didn't even think you thought that . I was just confused as to how one can be true without the opposite being true as well.

 

[txag]

I didn't say you said that . I didn't even think you thought that . I was just confused as to how one can be true without the opposite being true as well.

i suppose the opposite is true, ollie. you use a poor bull you probably won't see much change in the bottom enders, but i would think you certainly will in the top cows (& not a good change, either). not sure where this fits in to your discussion, though?

 

[ollie]

One point of interest that I would like for you to address Frankie which I am not sure I understand.
If I am not wrong the epd figure is the number a given sire "should" produce which is one half of his genetic potential when mated to the average cow within the breed.
An example would be bull X with a ww of +50 should sire calves 25 lbs heavier on average than bull Y with a ww of +25 .
These formulas if for an angus bull would be calculated using the average of all the angus cows ww as the divider of each of the respective bulls progeny.
For argument lets say the average angus cows ww epd using the marc ABC epd is zero . What should we expect when bull Y and Bull X are mated to a set of huge Maine cows with a ABC epd of +50?
How would that vary when the same bulls were mated to a set of small Jersey cows with an ABC epd of -100?
Am I right in thinking the Jerseys would show more genetic expression from the bull because they are a smaller denominator ?
Conversley wouldn't the higher preformance set of mains show less difference between the two bulls?

Try this example, two bulls each appear to be functionally sound. The EPDs for weaning weight are +35 and +15, respectively. The first bull is expected to produce calves 20 pounds heavier than is the second bull. The progeny would be 35 or 15 pounds, respectively, heavier at weaning than the average in the reference breed. If, on the other hand, they're mated to cows above average in performance, then the magnitude of the increased weight would be smaller. However, the 20 pound average difference in progeny performance between the two bulls should be constant if the bulls are mated to cows of similar genetic merit. The EPD value is the best predictor of performance of future progeny of a sire in comparison with progeny of other sires when both are mated to comparable cows.

This is copied from this site.http://sfbfp.ifas.ufl.edu/usesum.html

Txag you never really commented on the article.. what do you think?

 

[Frankie]

One point of interest that I would like for you to address Frankie which I am not sure I understand.
If I am not wrong the epd figure is the number a given sire "should" produce which is one half of his genetic potential when mated to the average cow within the breed.

EPDs won't tell you what bull will produce. They are a means to compare two or more animals of the same breed. He contributes half the genetics to every calf, good or bad.

An example would be bull X with a ww of +50 should sire calves 25 lbs heavier on average than bull Y with a ww of +25 .

Stop the presses, Ollie and I agree.

These formulas if for an angus bull would be calculated using the average of all the angus cows ww as the divider of each of the respective bulls progeny.

You've lost me here.

For argument lets say the average angus cows ww epd using the marc ABC epd is zero . What should we expect when bull Y and Bull X are mated to a set of huge Maine cows with a ABC epd of +50?

I assume the MARC ABC is the Across Breed EPDs? Under any circumstances, we should expect the calves from bull X to weigh 25 more pounds than from bull Y (if they're the same breed) and mated to similar cows under similar management practices.

How would that vary when the same bulls were mated to a set of small Jersey cows with an ABC epd of -100?

It shouldn't vary. You should still calves sired by bull X to weigh 25 more pounds than bull Y's calves. Will they weigh the same as the Maine calves? I'd doubt it.

Am I right in thinking the Jerseys would show more genetic expression from the bull because they are a smaller denominator ?
Conversley wouldn't the higher preformance set of mains show less difference between the two bulls?

You'll have to find someone smarter than me to give a real answer to this one, Ollie. I'd expect you would see more difference in the Angus/Jersey calves (as compared to straight Jersey calves) than you would see in the Maine calves (as compared to straight Maine), but, I can't speak to "small denominator".

 

[Frankie]

I didn't say you said that . I didn't even think you thought that . I was just confused as to how one can be true without the opposite being true as well.

i suppose the opposite is true, ollie. you use a poor bull you probably won't see much change in the bottom enders, but i would think you certainly will in the top cows (& not a good change, either). not sure where this fits in to your discussion, though?

A friend of mine says, "the bull always contributes half the calf's genetics, unless he's a sorry bull. Then he generally contributes 90%." Not true, of course, but it sure seems that way.

 

[ollie]

It shouldn't vary. You should still calves sired by bull X to weigh 25 more pounds than bull Y's calves.

I from experience doubt that to be true. If on an 800lb cow there is 25# diffgerence then on a 1600# cow there should be more difference even if the bull contributed the same amount of preformance.

 

[Frankie]

Try this example, two bulls each appear to be functionally sound. The EPDs for weaning weight are +35 and +15, respectively. The first bull is expected to produce calves 20 pounds heavier than is the second bull. The progeny would be 35 or 15 pounds, respectively, heavier at weaning than the average in the reference breed. If, on the other hand, they're mated to cows above average in performance, then the magnitude of the increased weight would be smaller. However, the 20 pound average difference in progeny performance between the two bulls should be constant if the bulls are mated to cows of similar genetic merit. The EPD value is the best predictor of performance of future progeny of a sire in comparison with progeny of other sires when both are mated to comparable cows.

This is copied from this site.http://sfbfp.ifas.ufl.edu/usesum.html

I think this person is confused between "average" and "0" EPDs. 0 is always zero, set as a base by different breeds different years. Angus used the data from about 1977. Angus breed EPD averages change twice a year, each time a new sire summary is published. The average Angus WW EPD is around 36 lbs. We've added 36 lbs of weaning for only about 2.5 lbs of BW since EPDs were set at 0.

I don't understand what "magnitude of the increased weight" means? I think he's simply wrong if he's suggesting that a bull's contribution is more on sorry cows than good cows. Yes, the calves from good cows will likely weigh more. And the sorry cows might produce substantially better calves if bred to a bull with high EPDs, but the difference in bull X and bull Y should still be there, across the board. The bull is contributing half the genetics to the calf in either case.

Thanks for the link. Now that I've shot my mouth off, I'll go read it.

 

[Frankie]

It shouldn't vary. You should still calves sired by bull X to weigh 25 more pounds than bull Y's calves.

I from experience doubt that to be true. If on an 800lb cow there is 25# diffgerence then on a 1600# cow there should be more difference even if the bull contributed the same amount of preformance.

Why?

 

[ollie]

Why what?

 

[Frankie]

Frankie wrote:

It shouldn't vary. You should still calves sired by bull X to weigh 25 more pounds than bull Y's calves.

Ollie wrote:

I from experience doubt that to be true. If on an 800lb cow there is 25# diffgerence then on a 1600# cow there should be more difference even if the bull contributed the same amount of preformance.

Why do you doubt that the calves sired by bull X, when bred to an 800 lb cow will not weigh 25 more pounds than if the same cow was bred to bull Y?

 

[ollie]

Frankie wrote:

It shouldn't vary. You should still calves sired by bull X to weigh 25 more pounds than bull Y's calves.

Ollie wrote:

I from experience doubt that to be true. If on an 800lb cow there is 25# diffgerence then on a 1600# cow there should be more difference even if the bull contributed the same amount of preformance.

Why do you doubt that the calves sired by bull X, when bred to an 800 lb cow will not weigh 25 more pounds than if the same cow was bred to bull Y?

The reason that I doubt that is if you believe the epd's to be correct, you have to believe they are only correct only on the average. If on average cows bull X calves are 25lbs heavier than bull Y's then on the big end of the cow size spectrum they need to weigh more and the small end of the cow size spectrum they need to weigh less because the preformance that the cow contributes changes even though the bulls remain the same.

 

[ollie]

Frankie you aren't thinking no matter what you breed the bulls to that you will get calves 25# heavier from bull x when compared to bull Y exactly . I would think that would most likely never happen. It is only an average. Depending on the genetic variation in each bull the genetic possibility of ww could be 200# either way of the average calf in the pen.Or did you know that? :lol:

 

[Frankie]

Frankie wrote:

It shouldn't vary. You should still calves sired by bull X to weigh 25 more pounds than bull Y's calves.

Ollie wrote:

I from experience doubt that to be true. If on an 800lb cow there is 25# diffgerence then on a 1600# cow there should be more difference even if the bull contributed the same amount of preformance.

Why do you doubt that the calves sired by bull X, when bred to an 800 lb cow will not weigh 25 more pounds than if the same cow was bred to bull Y?

The reason that I doubt that is if you believe the epd's to be correct, you have to believe they are only correct only on the average.

One more time: an EPD is the best method available to compare one animal to another for breeding purposes in your herd.

If on average cows bull X calves are 25lbs heavier than bull Y's then on the big end of the cow size spectrum they need to weigh more and the small end of the cow size spectrum they need to weigh less

I think you're suggesting if we have a 25 pound average increase in the overall herd WW, the higher producing cows will produce calves that will wean more than 25 pounds than they would produce if bred to bull y, thus the lower producing cows must produce calves that will weigh less than the 25 pounds their calves would weigh if they were bred to bull y? Is that what you're telling me?

because the preformance that the cow contributes changes even though the bulls remain the same.

Why would the Jersey cow's performance change (excluding management, age, sickness)?

 

[Frankie]

Frankie you aren't thinking no matter what you breed the bulls to that you will get calves 25# heavier from bull x when compared to bull Y exactly . I would think that would most likely never happen. It is only an average.

Yes, EPDs are not an exact science. They are an indicator of a breeding animal's production potential, not a gurantee, thus the EPD, not GPD.

Depending on the genetic variation in each bull the genetic possibility of ww could be 200# either way of the average calf in the pen.Or did you know that? :lol:

Again, EPDs will never, ever tell you what something will weigh. Not 200, not 400, not 50 lbs. They will simply tell you that if you breed bull x with a 50 lb WW, you can expect the calves he sires to wean 50 lbs heavier than if you bred those same cows, same management to a bull (same breed) with a ww EPD of 0. If you have a variable cow herd, you will have variable weights on calves, sired by the same bull. Or did you know that?

You're making this too hard, Ollie. But I'm trying to keep up.

 

[ollie]

Forget it Frankie. I never was a very good teacher. I am sure I have it all wrong. I don't care if you use epd's . I am quite sure you don't care if I don't . Maybe from all this wasted "Ink"People can learn all the arguments if not all the answers.

 

[brokenmouth]

Forget it Frankie. I never was a very good teacher. I am sure I have it all wrong. I don't care if you use epd's . I am quite sure you don't care if I don't . Maybe from all this wasted "Ink"People can learn all the arguments if not all the answers.

i think thats the best idea cause if this conversations gets any bigger and yall dont stop this fussin macons gonna have to buy a new server . you need to leave some room for some of the rest of us to argue :lol: either that or were gonna see the firs t digital fistfight in history :lol:

 

[ollie]

Frankie , your not going to like this. I talked to a friend the other day and they said at Denver several breeds were meeting ( Simmental , South Devons, Red Angus , Salers, Maybe Limi's etc. ) not trying to be factual with the breeds but it was some of these and maybe some more. They were working in conjunction and were in the planning stages. Hmmmmm.
Maybe KB can tell us what they were working on.Wouldn't be epd's would it?