You Would be Crazy not to Test!

[Mike]

The formulas/models used to calculate EPDs weed out environmental factors. There is no data sampling heavily loaded to certain environmental influences because genetic heritability is constant across all environments.

"The environment alone of course won't change genetics."

Please explain how the depressed apatite and increased body temperature induced by ergovaline is tabulated by the formulas and models when more than half the stock in the u.s.are grazing grasses other than fescue. If fescue toxicity has an influence on WW or YW or BW or Marbling etc, and the resistance to the toxicity is variable from sire to sire, how are the genetic models picking that up when large parts of data aren't on fesuce.

Indexing within contemporary groups. The actual WW of calf #1 raised in Florida is not compared directly to calf #2's raised in Michigan. Heck, it is not even directly compared to calf #3 which is a 1/2 mile down the road but in another pasture & contemporary group.

I've heard of people thinking they can cheat the models by creeping but not reporting it. Nope. It all works out eventually.

BIF guidelines define a contemporary
group as "a group of cattle of similar age that
are of the same breed and sex and have been
raised in the same management group
(same location, on the same feed and
pasture, etc.)."
Contemporary groups are formed to
allow genetic differences from one animal to
another to be compared without the
influence of the environment or other
factors that could affect performance not
attributed to genetics.

 

[redrobin]

The formulas/models used to calculate EPDs weed out environmental factors. There is no data sampling heavily loaded to certain environmental influences because genetic heritability is constant across all environments.

"The environment alone of course won't change genetics."

Please explain how the depressed apatite and increased body temperature induced by ergovaline is tabulated by the formulas and models when more than half the stock in the u.s.are grazing grasses other than fescue. If fescue toxicity has an influence on WW or YW or BW or Marbling etc, and the resistance to the toxicity is variable from sire to sire, how are the genetic models picking that up when large parts of data aren't on fesuce.

Indexing within contemporary groups. The actual WW of calf #1 raised in Florida is not compared directly to calf #2's raised in Michigan. Heck, it is not even directly compared to calf #3 which is a 1/2 mile down the road but in another pasture & contemporary group.

I've heard of people thinking they can cheat the models by creeping but not reporting it. Nope. It all works out eventually.

BIF guidelines define a contemporary
group as "a group of cattle of similar age that
are of the same breed and sex and have been
raised in the same management group
(same location, on the same feed and
pasture, etc.)."
Contemporary groups are formed to
allow genetic differences from one animal to
another to be compared without the
influence of the environment or other
factors that could affect performance not
attributed to genetics.

I understand all that Mike. If the angus bull 878 has a ww of 50 and angus bull 678 has a ww of 60 and both have accuracies of .99 but 75% of the data has been collected in an environment different than yours, there can be environmental influences where the bull 678 will predictably sire calves that weigh less than the 878 bull in your environment. If you live where the data sampling has mostly been gathered, the chances of the data being accurate is greater, thus my environmental statement in the statement about pigs.

 

[redrobin]

A better example is the ME epd in the RA breed. One of the original reasons for the ME epd was to select against large livers and gut mass. The science supposedly was that large livers and gut masses were inefficient users of energy. I promise that large gut masses and large livers are useful on washy toxic fescue. Cattle without large gut masses and I presume large livers are less efficient for me. It takes more energy for them to live here and do their job, not less. Large portions of the data regarding the RA ME epd are gathered on grasses other than fescue.

 

[knabe]

Wrong

 

[Mike]

Well............not immediately anyway.

 

[Mike]

Read this book to understand how EBV/EPD models work in detail:

http://books.google.com/books?hl=en&lr=&id=bnewaF4Uq2wC&oi=fnd&pg=PR5&dq=linear+models+for+the+prediction+of+animal+breeding+values&ots=05GMY0OvUf&sig=7LZTDkJlMxBOz5UFtvBM-ovGTTU

Then you can explain to us. :lol:

 

[3 M L & C]

Genetics are genetics. No matter where the animal is its genetics are the same. It's ability to perform in certain circumstances might be different but its genes are the same. Take yourself for example you would have the same hair and eye color if you were raised in the middle of New York City or in the middle of nowhere like western kansas. Ones DNA will never change.

 

[knabe]

Genetics are genetics. No matter where the animal is its genetics are the same. It's ability to perform in certain circumstances might be different but its genes are the same. Take yourself for example you would have the same hair and eye color if you were raised in the middle of New York City or in the middle of nowhere like western kansas. Ones DNA will never change.

Nonsense

 

[redrobin]

Try taking a cow herd from sea level to above 6000 ft. See how the ww's correlate to the ww epd.Environment plays a part. Pigs are raised in a uniform environment. So are chickens. Cattle are not.

 

[knabe]

The biggest variable in cattle are the humans.

Why not search for markers there and eliminate the low profit ones.

Perhaps domit through regulation and subsidies.

 

[Mike]

Try taking a cow herd from sea level to above 6000 ft. See how the ww's correlate to the ww epd. Cattle are not.

Actual weaning weights don't really correlate to a WW EPD which cannot be used for prediction. EPD's are only to gauge the genetic "Difference" between the progeny of two animals.

 

[knabe]

how is behavior eliminated from the equation?

 

[3 M L & C]

Genetics are genetics. No matter where the animal is its genetics are the same. It's ability to perform in certain circumstances might be different but its genes are the same. Take yourself for example you would have the same hair and eye color if you were raised in the middle of New York City or in the middle of nowhere like western kansas. Ones DNA will never change.

Nonsense

If an individuals DNA changed how would they be able to test and find out parentage? A change in environment has nothing to do with DNA. I do agree that some animals do diferent in diferent areas like redrobin said but the DNA doesn't change.

 

[redrobin]

Try taking a cow herd from sea level to above 6000 ft. See how the ww's correlate to the ww epd. Cattle are not.

Actual weaning weights don't really correlate to a WW EPD which cannot be used for prediction. EPD's are only to gauge the genetic "Difference" between the progeny of two animals.

If you move cow A which has a weaning wt epd of 40 and cow b with a weaning wt epd of 50 from sea level to 6000 ft then the difference between the wt of the progeny should be 10lbs on average and cow b should be 10 lbs heavier. That won't be true if cow b has brisket disease. Environment is a factor. Facts are facts.

 

[knabe]

dna can change, especially germline cells resulting in defects, the polled gene and just variation in general. if 1680's parentage is correct, he too had his dna change. snps have a rate of change. it's just nonsense that dna is static.

 

[knabe]

If an individuals DNA changed how would they be able to test and find out parentage?

cause that part didn't change. some parentage issues are because the dna changed.

people change at a lower rate than dna does.

 

[RSL]

Try taking a cow herd from sea level to above 6000 ft. See how the ww's correlate to the ww epd. Cattle are not.

Actual weaning weights don't really correlate to a WW EPD which cannot be used for prediction. EPD's are only to gauge the genetic "Difference" between the progeny of two animals.

If you move cow A which has a weaning wt epd of 40 and cow b with a weaning wt epd of 50 from sea level to 6000 ft then the difference between the wt of the progeny should be 10lbs on average and cow b should be 10 lbs heavier. That won't be true if cow b has brisket disease. Environment is a factor. Facts are facts.

If you have cow a and b mated to the same bull at sea level, you will usually see a 10 pound heavier calf from b. If you move them to 6000' + you will still see a heavier calf from b. You can't compare a cow at sea level directly to a cow at 6000' as they are very different contemporary groups. The environment may limit expression of differences, but the genetic differences are still there.

 

[redrobin]

Actual weaning weights don't really correlate to a WW EPD which cannot be used for prediction. EPD's are only to gauge the genetic "Difference" between the progeny of two animals.

If you move cow A which has a weaning wt epd of 40 and cow b with a weaning wt epd of 50 from sea level to 6000 ft then the difference between the wt of the progeny should be 10lbs on average and cow b should be 10 lbs heavier. That won't be true if cow b has brisket disease. Environment is a factor. Facts are facts.

If you have cow a and b mated to the same bull at sea level, you will usually see a 10 pound heavier calf from b. If you move them to 6000' + you will still see a heavier calf from b. You can't compare a cow at sea level directly to a cow at 6000' as they are very different contemporary groups. The environment may limit expression of differences, but the genetic differences are still there.

:lol: Wow. I guess you guys win.

 

[knabe]

We all lose if we all use the test.

 

[Mike]

If you move cow A which has a weaning wt epd of 40 and cow b with a weaning wt epd of 50 from sea level to 6000 ft then the difference between the wt of the progeny should be 10lbs on average and cow b should be 10 lbs heavier. That won't be true if cow b has brisket disease. Environment is a factor. Facts are facts.

If you have cow a and b mated to the same bull at sea level, you will usually see a 10 pound heavier calf from b. If you move them to 6000' + you will still see a heavier calf from b. You can't compare a cow at sea level directly to a cow at 6000' as they are very different contemporary groups. The environment may limit expression of differences, but the genetic differences are still there.

:lol: Wow. I guess you guys win.

There are no winners and losers, except for those that are skeptical of EPD's mainly because we don't comprehend the uses of covariances in computational equations.

The 3 words "Expected Progeny Differences" tell the whole story. The word "expected" is not absolute but the best thing we have at this time.