More on EPDs

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Nesikep
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More on EPDs

Postby Nesikep » Thu Sep 14, 2017 12:34 am

Hillsdown posted this on her page.. I quite enjoyed the read

:deadhorse: yeah, I know :deadhorse:


Understanding EPD's


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Are they an exact science? An incomplete math equation? A useful tool? Or are they a dangerous toy?

In his book, The Lion, the Witch and the Wardrobe, CS Lewis uses an illustration of Santa Claus meeting up with the three children once they discover the magical kingdom of Narnia. Santa gives each one of the children a gift to assist them in staying safe while they're in Narnia. Lucy is given a dagger and a special cordial that can heal the sick; Susan is given a bow and arrows, and a special horn that will always bring help when blown; and Peter is given a sword. As Santa's sleigh departs he looks back and says, "Remember children, these gifts are tools and not toys!"

The first image shows the BLUP (Best Linear Unbiased Prediction) equation. If you're like me, seeing something like this is like looking at a website-coder's computer screen. A feeling of awe overcomes you, and in that moment, you'll trust absolutely anything you're told.

What we are so often told, is that EPD's or EBV's are a science that we need to use as cattle breeders to improve our genetics and in effect an animal's productivity, a herd's profitability and a family's prosperity.

The second image demonstrates what trusting EPDs for the last 36 years has done. In essence, Angus steers in US feedlots are $144 more profitable today than they were in 1980. Big win if you run a feedlot!
Also, the graph shows us that Angus cows are $136 per year more expensive to run today than they were 36 years ago. Big loss if you run a cow/calf operation.

So, if you're a cow/calf operator who sells weaned calves, you lose $136 so that someone else can make $144. Is this genetic improvement? Or is it just genetic change?

Now, are EPDs science? In Science if two laboratories do the same experiment with the same procedure and ingredients they will always have the same outcome. e.g. If I hold my arm out holding an apple in Texas and my brother in South Africa does the same, and we let go of our apples, they fall to the ground. Every single time. That is science.

If I sell a cow and calf to my neighbor, also a registered Angus breeder, and at weaning the calf is weighed and ratio'ed with my neighbor's calves, his EPDs will reflect where he ranked in a contemporary group set up by my neighbor.
If the pair had remained on my side of the fence and been ratio'ed with my calves, his EPDs would reflect where he ranked in a contemporary group set up by myself.

Let's assume:
My neighbor and I have very different herds in terms of quality and genetics.
My neighbor doesn't manipulate contemporary groups, I have manipulating contemporary groups to benefit outliers down to an art.
My neighbor and I have the same grass, same nutrition and have had an identical season. We stock at the same rate, using the same herd sizes in each pasture. We use identical vaccinations and supplements given on the same days.
We use the same scale with the same person reading the weights.

So naturally, there should be no difference in the calfs EPDs -whether he was retained by me or sold to my neighbor in dam? Correct? Wrong!

There is a 100% chance of these EPDs having different outcomes and therefore EPDs are not Science. Not even close.

I'll argue that EPDs are an incomplete math equation.

The system makes some incredible assumptions.
1. That breeders all measure and weigh their cattle.
2. That breeders all measure and weigh their cattle accurately.
3. That everybody's herd is equal. eg. Having a ratio of 100 in herd A is equivalent to having a ratio of 100 in herd B.
4. That contemporary groups are honest and not manipulated.

None of these assumptions are true and yet, we are provided a spread of numbers that we are encouraged to have faith in and are told that they are science.

Even more concerning is that cattle are given values for traits that neither they nor their parents nor offspring have even been measured in.
e.g. Ribeye Area and FAT.
(A remarkably small percentage of cattle with REA and FAT EPDs are actually measured. But they still get EPDs. And if their calves are not measured, they'll still get EPDs too.)

Please try and follow this logic with me. When I was in high school I didn't play Chess, but I played Cricket and took History. If there were EPDs for me as a high school student other than direct measurements, like a batting average in Cricket or an Exam score for History, then I could have been given EPDs for Batting and History. What EPDs claim to be allowed to do is to give scores for tests I hadn't even taken. So even though I didn't play chess, the formula would give me a chess score based on how I was at Math and Accounting. As it would claim that these two activities correlate. And then also work into my score the fact that I did sports. Chess and sports correlate negatively, so because I was good at sports and poor at math, my Chess EPD would be low.

One generation later, my kids don't play Chess either, but because I had a poor Chess EPD, even though I never played Chess, they inherit my bad Chess EPD and my wife's poor EPD for Chess (She did play chess, but at another school, so they don't take her numbers into account at all).

Is it just me that finds this illogical?

The comment about my wife coming from a different school is what happens to cattle brought in from different countries. Decades of data and performance testing in New Zealand for example translates to nothing if it is exported to the US.

Forgive me for getting technical, but this is clearly not science and certainly not a complete math equation.

But, it is a tool than can work, if used in context and when backed by raw data and an understanding of the herd the animals come from.

If the breeder of the animal measures all the traits that are published as EPDs, has a well managed herd with great data capturing and is honest with his scale and doesn't manipulate contemporary groups, then yes the EPDs on his animals are a very useful tool. I'll go as far as to say that one can incorporate these EPDs into your breeding decisions and give them significant weight provided the phenotype and pedigree is sound and of high quality.

When do they become a dangerous toy?

EPDs are an extremely dangerous toy when used out of the afore mentioned context.

Using EPDs for marketing cattle for high premiums or publishing EPDs for traits that aren't measured, or even worse, traits that can't be measured instead of understanding cattle for what they are and what their purpose is can be very dangerous.

(Traits that can't be measured like udder score. You describe an udder score, you don't measure it. And each score is described by a different person. Science is not described, it is measured).

The second image demonstrates an example of a maternal breed that through genetic progress (genetic change) over 36 years has become a terminal breed. This almost entirely based on the use of EPDs. The world famous Angus mother cow has now become an average Charolais.

Thankfully though, there is still a remnant of breeders who still breed cattle with common sense and caution. Who use EPDs for what they are and only trust them as much as they trust the cow or bull that produced them. These breeders are the saviors of the industry, who will have good feet, and real tangible muscle and docility and softness when the industry realizes that things got out of hand. We will be forced to turn to the conservative breeders when the "progressive" breeder's tank runs out of gas.

If I end this here, my phone will erupt with calls and texts from my industry friends and colleagues. What about genomics they'll say, genomics and GE infused EPDs solves all of this.

That's why I didn't end there.

The mapping of the bovine genome was a remarkable discovery and is real science. This has enabled breeders to identify genes for color, horn status, genetic defects etc. This is all amazing and we should all be grateful for it.

Then we took it one step further, we started identifying genetic markers for the traits that we're measuring and formulating into EPDs. By combining genomics and conventional EPDs we developed GE-EPDs. Its like the hybrid car, only more reliable... or so they say.

Doing a 50K or 75K SNP or genomic test on an unproven calf can improve the accuracy of its EPDs for up to the equivalent of it having 7-12 offspring. That is helpful indeed. Not a silver bullet, but better than what we had previously.

Again, it may just be me, but the issue I have with this is the process from where the gene is identified to where it becomes an actual number. So one identifies the gene for marbling and then it becomes a 0.27 marbling score when combined with the raw data (If we're lucky enough to have any).

There is a magical bridge that transports that genetic marker into the EPD profile. This is a remarkable claim if there ever was one. And remarkable claims require remarkable evidence. In the case of GE-EPDs the evidence is not remarkable at all, its absent. The bridge is a bridge requiring a lot of faith.

Oh, but they'll say, we've changed now from the two step system to the one step system. Its a lot less complicated and saves a lot of time. It may be less complicated, but the bridge is still magical, mysterious and imaginary... unless they can demonstrate it to us in a remarkable way.
If the two-step system was a unicorn, the one-step system is Big Foot.

I would love for this to be true. And if it is demonstrated with remarkable evidence I will become a true believer.

Up until now, fluctuations in individual EPDs, phenotypes which are antagonistic with their own EPDs, and the type of cattle which are produced using full faith in the GE-EPD system are evidence enough to me that this is a dangerous toy, one being used to manipulate unknowing investors into believing that their potential purchase is indeed, scientifically, the best at what it is in the free world. This is cult like behavior.

Tom Lasater, founder of the Beefmaster breed famously said:

"Breeding cattle is easy. The difficult part is keeping it easy!"

Voila!


Link to the original facebook post https://www.facebook.com/permalink.php? ... 9980023978
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Re: More on EPDs

Postby True Grit Farms » Thu Sep 14, 2017 4:12 am

That opionion sure covers a lot, and there's more speculation than facts. Genomic testing can and does backup EPD's, and sometimes it disputes them. The more tools you have in your box the better the chance that you can get the job done. The AAA is the best cattle organization in the beef business. You can never catch the leader when your following behind them. How many breeders can tell you what to expect from a specific mating and be very close the majority of the time? A good Angus breeder and a good Hereford breeder can the majority of the time. Nothing is perfect and results can very, but breeding cattle using EPD's and DNA beats the heck out of guessing.
A black Angus cow bred to a black Angus bull will have a black calf. That's a fact and not a opionion. Another fact is that before ANGUS cattle influenced the US beef herd, US beef wasn't any better than imported beef on adverage. Australia has proven this again, and stepped up it's beef herd, supplying the world market with good quality beef, how did they do it? ANGUS
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Re: More on EPDs

Postby Nesikep » Thu Sep 14, 2017 11:13 am

AAA has done a wonderful job of marketing, I'll give them that credit, but where I have issues with the DNA tests is what's pointed out in the article.. the "magical bridge" between DNA and a number... And that's assuming that they know all the markers for something like tenderness.. what if there are more of them? What if some closely linked genes to the tenderness have negative consequences? (in humans, light hair is closely linked to blue eyes for example)

I also saw an article that was examining the $Beef EPD, and who it benefited.. It's not a worthless EPD, but it's use, overuse, or abuse hasn't been good for the cow-calf guy... Over some time (I can't remember how long), the profit per animal in the feedlot (where $Beef is relevant) increased by $140, but the cost to the producer to raise that animal increased by $130.. I'll have to go dig for the article
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Re: More on EPDs

Postby Ky hills » Thu Sep 14, 2017 12:09 pm

I will freely admit that there are a lot of people in fact probably most that are way smarter than me. I sometimes feel so inferior to a lot of folks on here that are able to comprehend the details and information available. In my humble understanding EPD's and Genomic testing are both intended to be tools available to help make decisions, and not for the numbers to be taken as exact science. I do know that over time the EPD's of young animals, bulls in particular can change dramatically, with more information submitted. The DNA testing increases the accuracy, on young animals from what I have heard it is about the equivalent of having records from 10-12 calves.
The way that I understand the $ W and $ B is that they are a collective combination of several EPD represented traits. I probably have some figures wrong so please forgive me. $W is a combination of CE, BW, WW, MM, while $B is more from YW, and carcass traits. I have always understood that the $B traits, and carcass traits in particular are antagonistic to maternal traits, therefore eventually the cow/calf producer is negatively affected.

My personal opinion is that it is becoming more and more common practice to select animals based on their numbers rather than visual appraisal. Which in turn is leading to structural soundness issues, and with the emphasis on end product, fertility is also being affected negatively.
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Re: More on EPDs

Postby cotton1 » Fri Sep 22, 2017 10:04 am

EPDs require accurate and honest data being turned in by each and every producer every time or the information will be flawed. I have been noticing the EPD values continue to get "better" or improve as time goes on. Is it because breeders have been using superior breeding stock over time? Maybe, but I dont think so. Its way to human nature and easy to turn in favorable numbers so that corresponding EPD values "look good".

One thing is for sure, the more a breeder buys into EPDs the more he will likely spend on chasing them.I have been guilty enough in the past to know, and my cattle herd has some pretty nice EPDs I will add. So think of it this way, there are way too many bulls out there to maintain the inflated value between registered stock and grade stock without some form of value added coming to play.Early on for example, simply having a registered bull was sufficient. The knowns about the bulls parentage and the paper on him made him worth more than a bull of equal composition and performance without the registration papers.What did it mean really? It meant selling a registered bull was more profitable than selling a non registered bull.I believe the bar keeps getting raised to encourage folks to spend their money. Thats my opinion, and mostly based off a lifetime of experience with both commercial grade cattle and registered cattle.

In the past the way to prove a bulls genetic purity was to breed him to 20 or more of his daughters. If no defects came about he was considered a good bull. Pre Ai days meant that majority of breeders were trying to validate his own herd bull in house. Could those guys lie back then? Sure, but I doubt it since the price would be loosing calves or creating a herd that was not good doing would be adverse for the breeder. With the EPD magic the bull of the month rotation can include yearling bulls who have never bred a cow but has "curve bender numbers".If he fails, oh well you already bought the semen and signatures and " here is this new, better one now".

I used to believe EPDs and will sorta use them some for now, but not like in the past. I have witnessed too many dishonest things in this industry to believe that every contributor turns in accurate data.My herd is mostly becoming closed and the more that happens the less breed EPDs mean. Likewise the more my own data and record keeping mean more to me, and hopefully to my customers.

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Re: More on EPDs

Postby Smallpotatoes » Fri Sep 22, 2017 6:48 pm

The article seems much more suited to inciting a riot than giving good advice. I'm a believer in EPDs, but also think they should be utilized in conjunction with all the other information provided. Epds shouldn't be the end all be all, visual appraisal shouldn't be the end all, but ignoring one or the other seems....silly.

Given the choice, why not buy a pretty truck with maintenance records. Makes more sense than buying one based on solely maintenance records or solely visual appraisal.
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Re: More on EPDs

Postby NEFarmwife » Wed Sep 27, 2017 8:25 pm

Going to disagree some, without targeting everything you stated.

We run a commercial operation and over the past few years, have been selling a few select bulls. These are commercial, however we do run Genomic testing. Just got our results back a few days ago and while they had NO IDEA who the sires were, these numbers for each group sired by... run fairly close to one another. They have a number here or there that were drastically different then their brothers but they also have mommas who contribute.

So if genomic testing is a "magical bridge" that isn't backed by science, how on earth do these half brothers score so intimately in range with one another if the folks who tested them, had no idea of their parentage?
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