another EPD question

[new_guy]

When a breeder decides to begin an EPD for a cow, does the breeder take and record the different parameters (BW, WW, YW, SC, etc.)? If so, is "fuzzy math" a common occurrence?

 

[Frankie]

When a breeder decides to begin an EPD for a cow, who records the different parameters (BW, WW, YW, SC, etc.)?

I'm not sure I understand the question, but I'll try an answer. EPDs aren't created by "a breeder", they're generally created by a breed association that uses information from more than one or two breeders.

 

[new_guy]

maybe I'm alittle confused about EPD's.
How are EPD's calculated for a specific cow? Are individual offspring weighted to determine parameters such as the BW, WW, YW?

 

[dun]

The individual animals performance and it's offspring plus it's relatives are all used to calculate EPDs for a given animal. To increase accuracy of a given trait you pretty much have to report all weights.

 

[Frankie]

maybe I'm alittle confused about EPD's.
How are EPD's calculated for a specific cow? Are individual offspring weighted to determine parameters such as the BW, WW, YW?

Yes, the weights of a cow's calf will be used in creating her EPDs. But to get more reliable EPDs and higher accuracies, they also use the weights of calves from the cow's sisters, aunts, daughters, etc. The more information, the more reliable the EPD.

 

[TheBullLady]

I think he's asking who actually does the calculations, not the importance of reporting.

I'm not sure about "commercial" cattle, if there even is a data base for that, but with registered cattle, you give your breed association certain data, and they compute the epd's based on the sire and dam and the information you report. Most EPD's also have an accuracy EPD, which will get lower the more progency of sire and dam that's reported.

 

[Aero]

Do you mean say you breed a bull with such and such epd's to a cow with such and such epds what are the off springs epds?

Basically you take the weaning weight, yearling weight, maternal weaning weight(if they are continental breed), and milk, epd of both parents and add them together. Then divide by two and you come out with the offsprings epd's just to check and see if I was right I did this with my own cattle and it came out to be exactly what the breed association had when I registered the calf.

for true EPDs (like the ones you stated) that is true. for some of the $Values and other more complicated stuff, it isnt that simple.

new_guy:

there are 3 basic steps in an animal's EPDs. with each step, the Acc will go up.

• 1. parental input.
  2. individual performance.
  3. offspring performance.

the parental input is pretty much a starting point for an EPD. the average of the parents' EPDs will be the individual's EPD.

when a breeder turns in the individuals weights and measurements, the EPD will be adjusted up or down according to how he/she ratioed in their contemporary group. usually if an animal ratios above 100 the EPD will go up. less than 100 it will go down.

when the individual has offspring that is weighed and measured, how they ratio in their own contemporary groups will determine how the EPD is adjusted.

if you use 2 bulls on your cows, you would ratio each animal against the group average and then average the ratios from bull A and do the same for bull B. whatever each bull's progeny ratio will determine how the EPD is adjusted if the weights are turned into a breed registry that does performance calculations.

 

[VanC]

Most EPD's also have an accuracy EPD, which will get lower the more progency of sire and dam that's reported.

Doesn't it get higher with more progeny?

 

[MikeC]

Most EPD's also have an accuracy EPD, which will get lower the more progency of sire and dam that's reported.

Doesn't it get higher with more progeny?

Not an "Accuracy EPD", but an Accuracy "VALUE" on the EPD's.

The more calves' data reported, the higher the accuracy of the EPD's.

 

[new_guy]

Thanks Aero, that's what I was wondering. Are there many cases where owners report "fake" weights and measurements?

 

[MikeC]

Thanks Aero, that's what I was wondering. Are there many cases where owners report "fake" weights and measurements?

Why would they? The truth comes out sooner or later.

 

[Frankie]

Thanks Aero, that's what I was wondering. Are there many cases where owners report "fake" weights and measurements?

I don't believe there are many cases where breeders cheat. Some, yes, but not a lot. The Association takes the information reported and creates reports, ratios, that are very helpful to the breeder in evaluating his individual cows and the entire herd. I've always felt like you would be shooting yourself in the foot to lie.

 

[Aero]

Thanks Aero, that's what I was wondering. Are there many cases where owners report "fake" weights and measurements?

of course there are some. if the animal gets any kind of usage in other herds, the EPDs will start to correct themselves.

one word of caution, if you see an animal that has numbers that head and shoulders above the rest, give it an extra year. plenty of people will jump on the "hot, new bull" bandwagon and do the research for you. usually the numbers will creep back toward the rest of the population.

 

[Frankie]

Thanks Aero, that's what I was wondering. Are there many cases where owners report "fake" weights and measurements?

of course there are some. if the animal gets any kind of usage in other herds, the EPDs will start to correct themselves.

one word of caution, if you see an animal that has numbers that head and shoulders above the rest, give it an extra year. plenty of people will jump on the "hot, new bull" bandwagon and do the research for you. usually the numbers will creep back toward the rest of the population.

I think that you're Precisely right. ;-)

 

[new_guy]

Thanks for all of the info from everyone. I’m trying to understand EPDs alitte better and have one more question.
Are Interim EPDs very reliable? I recently went to a bull sale and saw a 2 year old bull sell for $5,100. He had a great Interim EPD with a .05 accuracy. Why would a buyer spend that much money on a bull with such a low accuracy? Seems like the buyer is taking a pricey risk.

 

[Aero]

Why would a buyer spend that much money on a bull with such a low accuracy? Seems like the buyer is taking a pricey risk.

you understand more than many folks at those sales. hold onto that concept.