EPDs

[milkmaid]

Couple EPD questions for y'all.

#1 - What's the standard by which EPDs are calculated? Had someone ask me about where the "0" for CED, BW, WW, YW came from.

#2- Nursing ratio - I get that the first number is the number of calves the cow has had (not counting ET calves, right?), but what is that second number and how is it generated?

#3 - Market values such as ribeye, HCW, etc - are those full siblings to the bull, half siblings, genomic data, or where do those numbers come from in a sale catalog?

Thanks-

 

[Nesikep]

From my understanding, 0 is breed average

#2 I have no idea

#3 I think is often determined by ultrasound,

I'm sure someone will have more info than me on this....

 

[kenny thomas]

From my understanding, 0 is breed average

#2 I have no idea

#3 I think is often determined by ultrasound,

I'm sure someone will have more info than me on this....

I don't think 0 is breed average in any breed.

 

[Nesikep]

Actually, now that I think about it, you are quite right... Every breed usually lists what their breed average is, and it's not 0... So that remains unanswered..

 

[Lucky_P]

1. Zero may have been breed average...in the 'base' year in which the epd system was established...which might have been...1983 or earlier. So...breed average for any trait today is not zero; may have gone up or down, based upon trends within the breed.
Or, they may have agreed that 'no one likes zero', so they arbitrarily set breed average at...whatever... and breed average is now higher or lower than that original 'base' number.

2. I dunno - I never look at ratios...they don't mean much, if anything, to me in sire selection.

3. 'Carcass' trait epds...probably all of the above - measurements incorporated from offspring, related individuals, perhaps ultrasound data on the animal itself &/or offspring/relatives... and, with some breeds, genomic test results are being used to 'enhance' epds.

 

[bmoore87]

1. Agree with lucky they mostly change every year. If zero were average and say you have a bull with below average weaning weight it would probably look bad saying this bulls progeny are a negative number and loosing this many pounds.

2. Not sure according to ABS nursing ratio is the same as weaning ration which I think is based on calf weight so i assume you are speaking to something else?

3. "Comes mainly from 2 sources: 1) slaughter steer and heifer progeny, and 2) ultrasound scan data from primarily yearling bull and heifer progeny. Breed associations may publish carcass EPDs utilizing data from one or both of these sources. " Both methods have pretty similar results to each other.

 

[milkmaid]

So on those carcass traits... where do the values come from on yearling virgin bulls in a sale catalog? It can't be their actual progeny, right?

 

[bmoore87]

Good question, I think it initially comes from some combination of sires/ grandsires (possibly brothers) for a baseline. Alot of times on yearling bulls you see a P or I denoted by those epds and a really low accuracy show not much practical info is available. Curious to see if somebody knows for sure?

I know on the carcass most yearling bulls i have looked at the past couple of years have ultrasound or genetic testing done to increase the accuracy.

 

[Supa Dexta]

And lets expand on this. Lets say we had a bull in 2000 that had BW of 2.7, high accuracy for the sake of argument

And now in 2015 we have a bull with a BW of 2.7 - also high acc.

BW's have dropped in the last 15 years, The avg angus BW in 2000 was 2.7 and today is 1.7

On paper those bulls look equal compared against one another, but they aren't actually with the shift of time, one looks to have larger calves by a fair bit.

 

[Lucky_P]

SD,
Your 2000 model bull's epds would have been recalculated multiple times... likely would no longer be at 2.7; but he'd still be in the database.

 

[kenny thomas]

So if a bull with a BW EPD of 1.7 is ok is 2.7 not just 1 lb bigger. I cant tell the difference in 1lb and I dont think it will cause any calving problems either.

 

[Nesikep]

LuckyP is correct... you have to compare current EPD's. I looked at our new bull and his have changed since we bought him, but he's had no progeny yet.. Though I guess he's had siblings, etc that have been added to the database

 

[Supa Dexta]

The internet is starting to catch up, but if I had bought that bull back then I would only have his paper work in the file cabinet, nothing would be recalculated, nor would his acc improve in most cases with people not pure breeding and reporting.

So the ability now to look up old sires, their numbers are constantly being updated I take it?

 

[Nesikep]

They are, but as they get older, their accuracy increases, and I would guess the change on them would become insignificant after a while.. Especially true with popular AI bulls that get reported on, on one you have your milage may vary

 

[Supa Dexta]

No I mean just a bull bought and taken to a farm, for a commercial herd - where no other info is ever submitted on him (which is probably 90% of bulls out there). Sure some of his relations will change over time as their info is submitted, which can change his somewhat, but what about just his base numbers as things shift over time.


The old bull above for example, was a 2.7 over the old BW avg, which was higher. So now with a lower base BW he should be that much higher again, Lets say it was 85 lbs back then and 80 today (I don't know, these numbers are tricky to find) So the old bull would have started as a 2.7, but should now be a 7.7 as BW have dropped 5lbs over the years, and if I understand correctly.

So as I said, what once looked like a herd avg bull would now look to have really high BWs - despite being the same bull, having the same calves.

 

[Alan]

I don't run a registered herd anymore, I got tired of being nickled and dimed, I did spend some time trying to figure out epds. My conclusion was epds are nothing more than a very good guess at what you'll get. You may breed a bull with a 1.7 BW to a cow with a 0.8 BW and still get a 100 lber, but most of the time it's an easy calving low weight calf. The AHA adjusted each registered animal epds twice yearly, once in the spring and once in the fall. I remember a few cases were the hot new bull began it marketing campaign boasting a certain epd, let's say low BW with great growth, but through the years his BW was adjusted so much he appeared to be a cow killer and he disappeared.

When I was a member of the AHA they had an online explanation of EPDs that was pretty good, but it seems I have to give them more nickles and dimes to look at it now, so I found this link that explains things pretty well.

http://pubs.ext.vt.edu/400/400-804/400-804.html

 

[Lucky_P]

Supa...
Walking herdsire here is a 2005 model - this is probably his last go-round; even when we bought him in 2006, there was nothing 'new and exciting' behind him - just proven Angus genetics. Working in a commercial herd, there's been no information turned in on him. Accuracies are LOW - in the .12 to .25 range - merely based on his relatives. His epds have changed - though very little - since he hit the ground here as a long yearling.
CED dropped from +8 to +6, WW/YW not more than a pound or two different from his interim yearling epds; $EN has dropped about $5.
Nothing to give any heartburn.

Last 5-6 years, he's merely been doing clean-up behind AI. Truthfully, his own daughters have panned out better here than those sired by Angus AI sires with much more 'impressive' epds. His steers have been OK - don't compare to those sired by SH & SM sires, but have held their own against those by AN sires with much higher WW/YW epds.

 

[Amo]

Ratios are very simple. The first number is calves raised. Second is where they fall in their heard mates. 100 is average. So a calf with a weaning ratio is 95, then its 5% below average.

Myself I like ratios. Since your not supposed to compare animals from Joe's herd against Bob's herd, so I think ratios are useful. I still use epds more. If that cow raised a calf with a ratio of 4/108 vs 1/113, the first animal is better if epds are similar. If nothing else than cow longevity.