Entering performance data

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alexfarms

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I have noticed some interesting results coming from the way performance data is sent into the association for calculations of epds. I have felt that my closed line cattle weren't getting a fair comparison when I entered their calves as contemporaries to outcross calves for ratio calculation. At some point I began sending in weaning and yearling weights on the closed bred calves as a separate contemporary group from outcross calves, but I have always sent in birthweights as one contemporary group as long as the gestating cows were fed together. For 2008, I decided to send in birthweights as separate contemporary groups also and WOW does that make a difference! Alot of weight is placed on those birthweights in the calculation of epds. It will take a few years to see how much difference it makes, but I am very surprised at the results so far. It is logical that the inbreeding would lower the birthweights as compared to outcross calves, I just hadn't considered how that would effect all of the growth epd calculations. Is anyone aware of any breed associations, or genetic analysis of any kind, calculating the effect of inbreeding into epd calculations?
 

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alexfarms":3jedwqsp said:
I have noticed some interesting results coming from the way performance data is sent into the association for calculations of epds. I have felt that my closed line cattle weren't getting a fair comparison when I entered their calves as contemporaries to outcross calves for ratio calculation. At some point I began sending in weaning and yearling weights on the closed bred calves as a separate contemporary group from outcross calves, but I have always sent in birthweights as one contemporary group as long as the gestating cows were fed together. For 2008, I decided to send in birthweights as separate contemporary groups also and WOW does that make a difference! Alot of weight is placed on those birthweights in the calculation of epds. It will take a few years to see how much difference it makes, but I am very surprised at the results so far. It is logical that the inbreeding would lower the birthweights as compared to outcross calves, I just hadn't considered how that would effect all of the growth epd calculations. Is anyone aware of any breed associations, or genetic analysis of any kind, calculating the effect of inbreeding into epd calculations?

I don't know what breed you're raising, but it seems to me that if you're only comparing your closed bred calves to each other, you're not being fair. Sending the data from the closed bred calves as one group means that one or two of them are going to excel, no matter their performance. That's how contemporary groups work: something will be 100%, something higher, something lower.

For "SOOK", I don't know about other breeds, but the American Angus Assn doesn't compute EPDs from pedigree estimates. If a cow has Interim (I) EPDs, her calf won't have EPDs at all. When/if the data from that calf is reported to the Assn in a proper contemporary group, the "I" on the dam's EPDs will go away and the calf will then have Interim EPDs.
 
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alexfarms

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Frankie":1bdg5f4z said:
alexfarms":1bdg5f4z said:
I have noticed some interesting results coming from the way performance data is sent into the association for calculations of epds. I have felt that my closed line cattle weren't getting a fair comparison when I entered their calves as contemporaries to outcross calves for ratio calculation. At some point I began sending in weaning and yearling weights on the closed bred calves as a separate contemporary group from outcross calves, but I have always sent in birthweights as one contemporary group as long as the gestating cows were fed together. For 2008, I decided to send in birthweights as separate contemporary groups also and WOW does that make a difference! Alot of weight is placed on those birthweights in the calculation of epds. It will take a few years to see how much difference it makes, but I am very surprised at the results so far. It is logical that the inbreeding would lower the birthweights as compared to outcross calves, I just hadn't considered how that would effect all of the growth epd calculations. Is anyone aware of any breed associations, or genetic analysis of any kind, calculating the effect of inbreeding into epd calculations?

I don't know what breed you're raising, but it seems to me that if you're only comparing your closed bred calves to each other, you're not being fair. Sending the data from the closed bred calves as one group means that one or two of them are going to excel, no matter their performance. That's how contemporary groups work: something will be 100%, something higher, something lower.

For "SOOK", I don't know about other breeds, but the American Angus Assn doesn't compute EPDs from pedigree estimates. If a cow has Interim (I) EPDs, her calf won't have EPDs at all. When/if the data from that calf is reported to the Assn in a proper contemporary group, the "I" on the dam's EPDs will go away and the calf will then have Interim EPDs.

That is exactly why I do it that way......so that they are ratioed as a separate group. If all my cattle had similar inbreeding coefficients it wouldn't be necessary to ratio them separately. I think if you were doing it, you would understand why I do it this way. I copy Miles City alot, because they have been doing this stuff a long time. They were having trouble with the epds on their young cows and heifers. They studied it and determined that inbreeding deficiency affected younger mother cows more than older mother cows. I believe the AHA uses like a 60# adjustment for 2 year old dams and Miles City determined in their herd of inbreds a 100# adjustment factor should be used. As a solution Miles City began making separate contemporary groups for the 2 year olds calves. Another example they have found at Miles City is that the frame score charts don't fit the inbreds there. As the inbreds mature they climb up in the frame score charts used by the beef industry. The general conclusion is that inbreeding delays maturity. Have you ever done a sire daughter mating? A sire daughter mating would have an inbreeding coefficient of 25%. The Miles City cattle are mostly in the 30%'s and many without linebreeding showing up in the 3 generation pedigrees. Most of the inbreds I have are probably higher than the Miles City cattle in inbreeding coefficient. When the performance collecting craze started, the instruction was to group calves into as many different contemporary groups as possible in order to increase accuracy.
 

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alexfarms":13r3zico said:
That is exactly why I do it that way......so that they are ratioed as a separate group. If all my cattle had similar inbreeding coefficients it wouldn't be necessary to ratio them separately. I think if you were doing it, you would understand why I do it this way. I copy Miles City alot, because they have been doing this stuff a long time. They were having trouble with the epds on their young cows and heifers. They studied it and determined that inbreeding deficiency affected younger mother cows more than older mother cows. I believe the AHA uses like a 60# adjustment for 2 year old dams and Miles City determined in their herd of inbreds a 100# adjustment factor should be used. As a solution Miles City began making separate contemporary groups for the 2 year olds calves. Another example they have found at Miles City is that the frame score charts don't fit the inbreds there. As the inbreds mature they climb up in the frame score charts used by the beef industry. The general conclusion is that inbreeding delays maturity. Have you ever done a sire daughter mating? A sire daughter mating would have an inbreeding coefficient of 25%. The Miles City cattle are mostly in the 30%'s and many without linebreeding showing up in the 3 generation pedigrees. Most of the inbreds I have are probably higher than the Miles City cattle in inbreeding coefficient. When the performance collecting craze started, the instruction was to group calves into as many different contemporary groups as possible in order to increase accuracy.

And your goal for your ranching operation?
 
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alexfarms

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Frankie":2xjo146k said:
alexfarms":2xjo146k said:
That is exactly why I do it that way......so that they are ratioed as a separate group. If all my cattle had similar inbreeding coefficients it wouldn't be necessary to ratio them separately. I think if you were doing it, you would understand why I do it this way. I copy Miles City alot, because they have been doing this stuff a long time. They were having trouble with the epds on their young cows and heifers. They studied it and determined that inbreeding deficiency affected younger mother cows more than older mother cows. I believe the AHA uses like a 60# adjustment for 2 year old dams and Miles City determined in their herd of inbreds a 100# adjustment factor should be used. As a solution Miles City began making separate contemporary groups for the 2 year olds calves. Another example they have found at Miles City is that the frame score charts don't fit the inbreds there. As the inbreds mature they climb up in the frame score charts used by the beef industry. The general conclusion is that inbreeding delays maturity. Have you ever done a sire daughter mating? A sire daughter mating would have an inbreeding coefficient of 25%. The Miles City cattle are mostly in the 30%'s and many without linebreeding showing up in the 3 generation pedigrees. Most of the inbreds I have are probably higher than the Miles City cattle in inbreeding coefficient. When the performance collecting craze started, the instruction was to group calves into as many different contemporary groups as possible in order to increase accuracy.

And your goal for your ranching operation?
Make a living, how bout u?
 

Frankie

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alexfarms":2tp06982 said:
Frankie":2tp06982 said:
alexfarms":2tp06982 said:
That is exactly why I do it that way......so that they are ratioed as a separate group. If all my cattle had similar inbreeding coefficients it wouldn't be necessary to ratio them separately. I think if you were doing it, you would understand why I do it this way. I copy Miles City alot, because they have been doing this stuff a long time. They were having trouble with the epds on their young cows and heifers. They studied it and determined that inbreeding deficiency affected younger mother cows more than older mother cows. I believe the AHA uses like a 60# adjustment for 2 year old dams and Miles City determined in their herd of inbreds a 100# adjustment factor should be used. As a solution Miles City began making separate contemporary groups for the 2 year olds calves. Another example they have found at Miles City is that the frame score charts don't fit the inbreds there. As the inbreds mature they climb up in the frame score charts used by the beef industry. The general conclusion is that inbreeding delays maturity. Have you ever done a sire daughter mating? A sire daughter mating would have an inbreeding coefficient of 25%. The Miles City cattle are mostly in the 30%'s and many without linebreeding showing up in the 3 generation pedigrees. Most of the inbreds I have are probably higher than the Miles City cattle in inbreeding coefficient. When the performance collecting craze started, the instruction was to group calves into as many different contemporary groups as possible in order to increase accuracy.

And your goal for your ranching operation?
Make a living, how bout u?

No, we're not making a living, but we've been able to keep our heads above water for a long time.

The general conclusion is that inbreeding delays maturity.

Why would you want to delay maturity of your herd?
 

pdfangus

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My question is why such a high level of purposefull inbreeding?

inbreeding concentrates the genetics. good genetics and Bad genetics.

i was taught back in the dark ages when the earth was flat.......
that when you could not find and animal superior to what you had that you could breed to......
then it was time to consider inbreeding or linebreeding to my superior animal.

the key is to have a clear picture in your mind of what the superior animal looks and performs like.

I have also had the handicap of being a performance oriented breeder.
 
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alexfarms

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The general conclusion is that inbreeding delays maturity.

Why would you want to delay maturity of your herd?[/quote]

The purpose of inbreeding is not to delay maturity, it is to genetically improve the line. As inbreeding coeffient goes up, age at growth maturity goes up. I have also seen a problem with pelvic area in first calf heifers because of delayed growth maturity. It doesn't seem to be as hard to maintain fertility, though. With performance testing you fight the genetic antagonisms that are natural in cattle breeding. Some of the effects of inbreeding are negative antagonisms that you have to deal with. Genetically, because inbreeding increases homozygousity, it also increases predicability and uniformity. When you have a distinct separate line, then you can make improvements within that line so that when the inbreds are outcrossed the outcross calves will be more predictable and have more optimum performance. If you make the right inbreeding decisions, the inbred breeding stock will be desirable as seedstock for outcrossing in purebred or commercial operations. That is how any linebreeder hopes to make money. He selects and culls within the inbred line to improve it as much as possible, increasing the positive traits and decreasing the negative traits. Ratioing the inbred line separate just helps to identify performance within the line. I think there is scientific logic behind the notion that more improvement can be made by inbreeding seed stock than outcrossing seed stock. Although we all have the right to disagree.
 
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alexfarms

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pdfangus":239cpvsq said:
My question is why such a high level of purposefull inbreeding?

inbreeding concentrates the genetics. good genetics and Bad genetics.

i was taught back in the dark ages when the earth was flat.......
that when you could not find and animal superior to what you had that you could breed to......
then it was time to consider inbreeding or linebreeding to my superior animal.

the key is to have a clear picture in your mind of what the superior animal looks and performs like.

I have also had the handicap of being a performance oriented breeder.

You ask: Why such a high level of purposefull inbreeding? ...It is to maintain the line. I believe the line is desirable and needs to be maintained. I believe the line has the potential to have a positive impact upon the breed and industry. Maybe never a huge impact, but still, a positive impact. If I can increase the number of cattle within the line, I can actually decrease inbreeding coefficients and still maintain and improve the line.

You State: inbreeding concentrates the genetics. good genetics and Bad genetics..... Inbreeding does concentrate the genetics. Selection for good traits, increases the good genetics and culling for bad traits decreases the bad genetics.

If the law is that you don't inbreed until you cannot find a better animal outside your herd to breed to, then it should follow that you should inbreed when you can't find a better line out side your herd to breed to. Just goes to the value of an inbred line, the same as the value of a superior animal.

Performance breeding doesn't have to be a handicap, it can be a positive if you keep the whole idea of genetic improvement in perspective. If you just make matings to build epds, then yes that is a handicap, because you are ignoring too many other factors of genetic improvement.
 

Herefords.US

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Interesting posts, John! I've been looking at performance data from a different perspective.

I have concluded that I would need to randomly select 10-20% of my linebred cows each year and AI them to very proven bulls in order to "semi-fairly" compare the resulting EPDs of the sires/calves from my linebreeding program to outside blood.

But I'm still very early in the stages of developing a line where you're refining one that's been established.

I had looked at some closed herds, like Richard Day's, and concluded that the EPDs of their cattle had been adversely affected from a lack of broad comparison like I was looking at doing. Yet, you are saying such comparisons skew the data further.

Something to ruminate on.

George
 

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alexfarms":2m8flby3 said:
That is exactly why I do it that way......so that they are ratioed as a separate group. If all my cattle had similar inbreeding coefficients it wouldn't be necessary to ratio them separately. I think if you were doing it, you would understand why I do it this way. I copy Miles City alot, because they have been doing this stuff a long time. They were having trouble with the epds on their young cows and heifers. They studied it and determined that inbreeding deficiency affected younger mother cows more than older mother cows. I believe the AHA uses like a 60# adjustment for 2 year old dams and Miles City determined in their herd of inbreds a 100# adjustment factor should be used. As a solution Miles City began making separate contemporary groups for the 2 year olds calves. Another example they have found at Miles City is that the frame score charts don't fit the inbreds there. As the inbreds mature they climb up in the frame score charts used by the beef industry. The general conclusion is that inbreeding delays maturity. Have you ever done a sire daughter mating? A sire daughter mating would have an inbreeding coefficient of 25%. The Miles City cattle are mostly in the 30%'s and many without linebreeding showing up in the 3 generation pedigrees. Most of the inbreds I have are probably higher than the Miles City cattle in inbreeding coefficient. When the performance collecting craze started, the instruction was to group calves into as many different contemporary groups as possible in order to increase accuracy.

As far back I can remember it as always been very simple, if they are treated exactly the same, and are about the same age [ use to be a 90 day window, now its a 45 day window ] and sex, then they are put in the same contemporary group, the more in that group the greater the accuracy. I don't really agree with the practice of splitting contemporary groups on the basis of linebreeding, if raised exactly the same as your other calves, that are outcrosses, just so you can attempt to artificially elevate their Epd's because they do not perform as well or are late maturing due to high inbreeding. The fact that they are so inbred that it reduces their ability to perform basic traits such as good early growth should be recognized and reflected in their epd's, when put in the correct contemporary group.
 
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alexfarms

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]

As far back I can remember it as always been very simple, if they are treated exactly the same, and are about the same age [ use to be a 90 day window, now its a 45 day window ] and sex, then they are put in the same contemporary group, the more in that group the greater the accuracy. I don't really agree with the practice of splitting contemporary groups on the basis of linebreeding, if raised exactly the same as your other calves, that are outcrosses, just so you can attempt to artificially elevate their Epd's because they do not perform as well or are late maturing due to high inbreeding. The fact that they are so inbred that it reduces their ability to perform basic traits such as good early growth should be recognized and reflected in their epd's, when put in the correct contemporary group.[/quote]

You can do it that way if you like. It is logical to me that putting intensely inbred calves and outcross calves together in one contemporary group will be like comparing apples and oranges and the resulting ratios will not reflect the true genetic potential of the calves. If you want real world epds you need to split them into separate contemporary groups.
 
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alexfarms

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Herefords.US":qrug8o8b said:
Interesting posts, John! I've been looking at performance data from a different perspective.

I have concluded that I would need to randomly select 10-20% of my linebred cows each year and AI them to very proven bulls in order to "semi-fairly" compare the resulting EPDs of the sires/calves from my linebreeding program to outside blood.

But I'm still very early in the stages of developing a line where you're refining one that's been established.

I had looked at some closed herds, like Richard Day's, and concluded that the EPDs of their cattle had been adversely affected from a lack of broad comparison like I was looking at doing. Yet, you are saying such comparisons skew the data further.

Something to ruminate on.

George

The way to go would be to randomly mate your linebred bulls and proven AI bulls to outcross cows and compare the resulting outcross calves. That way inbreeding won't be a factor. Or sell a bull or some semen on your linebred bulls to a tpr breeder who has unrelated cows.
 

bigag03

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Incorrect contemporary groups are a major reason for the inaccuracy of EPDs. EPDs are supposed to be a comparison of how cattle from your herd perform against cattle from any other herd. By always segregating your inbred line from your outcross cattle, you are are creating a false sense of the performance of that line. The EPDs of the cattle in your inbred line are only valid within your herd and would be completely inaccurate for anyone else buying and breeding your cattle.
 

pdfangus

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alexfarms":3dw1v85j said:
pdfangus":3dw1v85j said:
My question is why such a high level of purposefull inbreeding?

inbreeding concentrates the genetics. good genetics and Bad genetics.

i was taught back in the dark ages when the earth was flat.......
that when you could not find and animal superior to what you had that you could breed to......
then it was time to consider inbreeding or linebreeding to my superior animal.

the key is to have a clear picture in your mind of what the superior animal looks and performs like.

I have also had the handicap of being a performance oriented breeder.

You ask: Why such a high level of purposefull inbreeding? ...It is to maintain the line. I believe the line is desirable and needs to be maintained. I believe the line has the potential to have a positive impact upon the breed and industry. Maybe never a huge impact, but still, a positive impact. If I can increase the number of cattle within the line, I can actually decrease inbreeding coefficients and still maintain and improve the line.

You State: inbreeding concentrates the genetics. good genetics and Bad genetics..... Inbreeding does concentrate the genetics. Selection for good traits, increases the good genetics and culling for bad traits decreases the bad genetics.

If the law is that you don't inbreed until you cannot find a better animal outside your herd to breed to, then it should follow that you should inbreed when you can't find a better line out side your herd to breed to. Just goes to the value of an inbred line, the same as the value of a superior animal.

Performance breeding doesn't have to be a handicap, it can be a positive if you keep the whole idea of genetic improvement in perspective. If you just make matings to build epds, then yes that is a handicap, because you are ignoring too many other factors of genetic improvement.

Okay.

Here is the deal...I don't know you and you don't know me...
I have no knowledge of your herd....
Therefore i have no knowledge of the intrinsic quality of your herd. No offense to you in particular is intended. My first comment was aimed at what were you trying to preserve.
I have run into a lot of folks who want to linebreed because that is the way herds of known quality do it. Many of these folks might be better off crossbreeding.

My point is that to embark on a linebreeding program there needs to be a reason to preserve the line. One or more great animals as the basis. Like Hancock quarter horses or Wye Angus. With cattle there ought to also be some genetic purity testing done on those selected foundation animals. Like sire daughter matings to demonstrate fault free genetic purity. these days it is a bit easier with DNA testing but DNA can only test for what is known. 35 sire daughter matings test for everything. Get a good performing animal that is genetically pure and fault free and I am all over linebreeding.

As for me performance breeding is not just stacking epd's thank you very much.
It involves performance testing and selection and culling within my herd. Every bull we raise goes through a third party bull test.
You have no more idea what I am ignoring than I have of what you are trying to concentrate.

enough said.
 
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alexfarms

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bigag03":2spmvcg2 said:
Incorrect contemporary groups are a major reason for the inaccuracy of EPDs. EPDs are supposed to be a comparison of how cattle from your herd perform against cattle from any other herd. By always segregating your inbred line from your outcross cattle, you are are creating a false sense of the performance of that line. The EPDs of the cattle in your inbred line are only valid within your herd and would be completely inaccurate for anyone else buying and breeding your cattle.

If I only owned the inbred animals and no outcross animals then would the epds for my inbreds be accurate "for anyone else buying and breeding my cattle"? I am not making a false comparison by segregating the inbreds into a separate contemporary group, because I am only comparing them to each other and not other outcross animals. I probably had the same reaction as you are now when I first noticed Miles City was segregating their first calf heifers into a separate contemporary group. If you stop and think about it a little bit you will realize that keeping them separate has no effect on other cattles epds at all. The more you split your cattle into separate contemporary groups, for valid reasons, the better genetic analysis you will get in the end result. It may be slower and take more calf crops, but it will be more accurate in the long run. Sure there are ways a person could build contemporary groups to make one sires calves look more favorable than another sires calves and that may be being done, but that is not what I am doing and I have never done that. If the genetic analysis took inbreeding affects into account in the anaylsis then splitting them for that reason would not be necessary, you could still do it and not be fudging the data though. Do you believe in heterosis? Do you believe in getting a genetic "snap" when you cross two inbred lines? If you believe in either one of those, then you ought to be able to understand why I want to get the best genetic analysis I can of the inbred line as it's own contemporary group.
 
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alexfarms

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pdfangus":2ankrtxv said:
alexfarms":2ankrtxv said:
pdfangus":2ankrtxv said:
My question is why such a high level of purposefull inbreeding?

inbreeding concentrates the genetics. good genetics and Bad genetics.

i was taught back in the dark ages when the earth was flat.......
that when you could not find and animal superior to what you had that you could breed to......
then it was time to consider inbreeding or linebreeding to my superior animal.

the key is to have a clear picture in your mind of what the superior animal looks and performs like.

I have also had the handicap of being a performance oriented breeder.

You ask: Why such a high level of purposefull inbreeding? ...It is to maintain the line. I believe the line is desirable and needs to be maintained. I believe the line has the potential to have a positive impact upon the breed and industry. Maybe never a huge impact, but still, a positive impact. If I can increase the number of cattle within the line, I can actually decrease inbreeding coefficients and still maintain and improve the line.

You State: inbreeding concentrates the genetics. good genetics and Bad genetics..... Inbreeding does concentrate the genetics. Selection for good traits, increases the good genetics and culling for bad traits decreases the bad genetics.

If the law is that you don't inbreed until you cannot find a better animal outside your herd to breed to, then it should follow that you should inbreed when you can't find a better line out side your herd to breed to. Just goes to the value of an inbred line, the same as the value of a superior animal.

Performance breeding doesn't have to be a handicap, it can be a positive if you keep the whole idea of genetic improvement in perspective. If you just make matings to build epds, then yes that is a handicap, because you are ignoring too many other factors of genetic improvement.

Okay.

Here is the deal...I don't know you and you don't know me...
I have no knowledge of your herd....
Therefore i have no knowledge of the intrinsic quality of your herd. No offense to you in particular is intended. My first comment was aimed at what were you trying to preserve.
I have run into a lot of folks who want to linebreed because that is the way herds of known quality do it. Many of these folks might be better off crossbreeding.

My point is that to embark on a linebreeding program there needs to be a reason to preserve the line. One or more great animals as the basis. Like Hancock quarter horses or Wye Angus. With cattle there ought to also be some genetic purity testing done on those selected foundation animals. Like sire daughter matings to demonstrate fault free genetic purity. these days it is a bit easier with DNA testing but DNA can only test for what is known. 35 sire daughter matings test for everything. Get a good performing animal that is genetically pure and fault free and I am all over linebreeding.

As for me performance breeding is not just stacking epd's thank you very much.
It involves performance testing and selection and culling within my herd. Every bull we raise goes through a third party bull test.
You have no more idea what I am ignoring than I have of what you are trying to concentrate.

enough said.

Nothing you have said has offended me. I just answered your points. Measuring the performance of cattle is just one element of genetic improvement.
 

pdfangus

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actually I think we agree on a lot of things but I am probably not communicating very well.

arthritis make this typing difficult so I tend to shortcut when I can.
 

bigag03

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I do believe in heterosis and inbreeding depression and even a small degree of heterosis from the crossing of inbred lines. The problem lies in the analysis of these things.

If I only owned the inbred animals and no outcross animals then would the epds for my inbreds be accurate "for anyone else buying and breeding my cattle"?

The answer to this question is YES! Until you use an outside sire to tie your herd to the rest of the breed OR someone uses one of your bulls in their herd and turns in the data, there is nothing in the EPD calculation to tie the EPD's into the database.

Also, your rationale that the way these inbred cattle perform when compared to each other is an accurate representation of how they will produce when used as an outcross is simply incorrect. As mentioned earlier, the only way to develop accurate EPDs in this scenario is to use your cattle in an outcross setting compared to other sires. EPDs are a means of comparison only and they are only as good as the comparisons used to make the EPD.

Just so we are clear, if your inbred line is considered a separate management system within your herd, make them a contemporary group; I don't have a problem with that. But while it helps the EPDs of that group, it still does not represent what you believe it does.

This all goes back to my statement last week in another post that the AHA database is not strong enough because of so many of these closed herds and the lack of testing multiple sires.
 

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North Central Texas
I believe in heterosis, inbreeding depression, and I strongly believe that you can cross two linebred lines of Herefords and get some heterosis from that cross that can/will be extended into further generations.

On the inaccuracy of raw EPDs of Herefords, I also agree with bigag03.

When comparing the EPDs of closed herds with others, if there hasn't been a significant amount of "head-to-head" competition in the herd with highly proven bulls, the resulting EPDs (not the performance data) just don't seem to be very useful.

On the other hand, if highly proven bulls of outcross lines are used, would the resulting EPDs accurately factor in the effect that heterosis and inbreeding depression has on the inbred line? I'd bet not.

EPD wise, it looks like the linebred cattle end up unfairly judged either way.

George
 

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