DNA testing

[legendrockranch]

What exactly is involved for "Bull accreditation for AI"?

Barb

[jamshundred]

I have considerable familiarity with the Dexter Cattle DNA Database at UC-Davis in California which contains both historical as well as contemporary Dexters. It was founded in 2004, and has continued to grow to become a really valuable resource for the Dexter breed. All Legacy breeders are required to DNA test their foundation stock for the preservation program and calves cannot be registered under the Legacy identifier unless they have been parentage confirmed so that the integrity of the pedigrees of the Legacy calves can never be questioned. There are also a number of breeders in the east who began to parentage test their herds and some breeders can now confirm several generations, ( some five or six) which lends considerable credibility to their herds. ( Chautauqua herd in NY and Dixie herd in Va are two of the largest in the database).

Someone inquired about registering a polled as horned or vice-versa. This HAS happened. A number of years ago a polled calf was born to "horned" parents and when the registrar questioned the registration. . . it came to light that for seven years a POLLED cow had been in the registry as horned. The animal nor any of the offspring were removed which still puzzles me! There was also a situation in the pass year or two where registrations were submitted with polled animals from horned parents. . . . . questioned. . .. and resubmitted as horned.

Cheating within a testing database. Yes. There IS a possibility that in the very beginning of maintaining parentage confirmations someone could cheat. If there is no pre-existing dam or sire the first one could be an animal not as described. However, if there were ANY connecting animals in the pedigree that made it into the database the slight of hand could possibly come to light. Usually if a person wishes to be dishonest it is most often done with cows, but can be done with a bull as well. When there are no safeguards in place than opportunity exists for those who are character challenged. One of the reasons we have such a problem clearing the name of Parndon Bullfinch is that the English lost complete faith in the breeder when it was discovered he had made substitutions in the herd. This was a breeder who was highly regarded and influential in the breed. As it happens, the substitutions he made were pure bulls from a herd in another country. . . . ( thank heavens) but that and some other issues completely destroyed the credibility of that herd and left the English with suspicions about every thing connected to him.

Parentage verification through DNA is a science of *exclusion* not one of inclusion. It is a simple matter to exclude a sire whose markers simply do not match, but it is more difficult to include a sire only without a dam with complete assurance. It takes many more than the standard markers used to have any degree of confidence. Especially in minor breeds small in number and with closely linked bloodlines. I will post a seperate example in a minute which might make it more understandable.

UC Davis tests 16 markers off the cattle genome, 11 of them are required by international standards to be certain markers. The other five they choose markers that are the most diverse. One of the markers that is used by UCD is identified as BM1818. In more than 300 Dexter cows in the Dexter database there are only FOUR different numbers recorded for this marker. There is little diversity in this marker or any of the others because US Dexters are a small gene pool. If your herd is closely related than the chance that a young bull in the herd might have similar markers to it's sire are excellent. I have two bulls from two different herds who have very similar markers. ( See the example)

The Cardiff project in England just distributed the information on their research. This project was able to identify "bottlenecks" in the breed based on the genetic samples, as well as the genetic diversity amongst the samples. The US samples were comparable in diversity to the Island Jersey cattle in England which have been secluded on an Island for many, many, many generations. Those of us involved in the Legacy preservation project were confident that would be the case because US Dexters were never "up-graded" or "out-crossed" until modern imports from England arrived and the genetics in the samples sent to England predated those importations. That project wasn't definitive in many areas some of us hoped for, but it certainly defined parameters and set a base for future research that I believe is currently being planned, and as DNA progresses, the cheats are going to be exposed. I am confident of this because the research is already so advanced it is knocking on the door.

I think that breeders who are able to afford parentage testing on their animals should give it serious consideration. Protect your herd and breeding interests into the future by giving it integrity backed by science. Consider adding your animals to the Dexter Database at UC-Davis. If you would like to check to see if there are connections you can make to existing animals/bulls send me a note and I will check for you. OR. . . .if you have a bull or cow you have had tested through ADCA please consider adding it to the Dexter database to continue to build this fantastic historical resource. Just send me the test report, and it will be done no charge.

<<<Why in God's name would anyone register anything with the PDCA. The people who had any dealings with the people that started the PDCA still remember how is was with them and the new ones will figure it out soon enough. <<

I'm going to respond to this because it was in this thread, and I think a reply is merited because of the implication that there is something wrong with PDCA or it's members. Many of the breeders who felt compelled to leave ADCA were members who had shepherded and nurtured ADCA through the years, or it would not exist today. Many were good Dexter people who were breeding Dexters long before most breeders today were old enough to drive. They were willing to sacrifice their own Dexter legacy in both an association and the Dexter breed they nurtured for their principals. . and I do not believe they made the choice without considerable deliberation. Mark Davis was the resident agent for ADCA in Delaware and served in leadership through the years. He has been breeding Dexters since the 1960's, and his herd of full blood Dexter cattle has been closed longer than the Woodmagic herd in England. The P-Bar herd in the west of the Piehota family is another long standing herd from which many of the full blood Dexters that can be identified today were bred. Jack Goodman in Idaho has been breeding since the 70's and Jim Johnson's O'Briar Hill herd in Ohio can be found in almost all modern pedigrees as he has been breeding since the late 60's or early 70's. Stan Cass was breeding in the 70's, as were the Fleherty's. Do you really think that men and women who nurtured the very foundation of our modern animals and it's association made such a drastic and personally troubling decision without feeling compelled to so based on their assessment of the situation at the time? I don't. And I think they are to be commended for their service and loyalty to the Dexter breed for these many decades.

Judy Sponaugle

[windmill]

As I agree with you that there were many good people that nurtured the ACDA through the years. The people that I had dealt with who broke off to start the pdca it was their way or no way. They want one way to happen if you did not agree with their opinion you were the problem. It was not for the good of the breed it was for their benefit or no ones. I try to get along with everyone and everyone is entitled to their opinion. When someone starts the cram things down peoples throat that is when I am done with them. As with everyone having their own opinions even if they differ that is the way it should be. When others force their opinions on other people they usually destroy the things they stand for by alienating themselves with people who think just like they do.

[jamshundred]

]Here are actual test results from four animals in my herd. The top two are two herd bulls, a cow, and an offspring. I don't have room for all the markers, so will just do the first six for explanation.

The marker numbers are along the top of the rows. Each animal ( and humans) receive a pair. . one from the father and one from the mother. In turn, a calf receives one of the two markers of the father, and one of the two markers of the mother. So. . . for fun. . which bull do you think is the sire of Lorelaidi? The first two are bulls, the third is the dam, Lorelaidi the calf.

BM1818 BM1824 BM2113 BRR CYP21 ETH3
LUKE 266 188 125/133 260/262 98/202 219 IVAN' 262/266 182/188 125/137 258/260 93/202 217

LEI 266 188 137 256/260 198/202 217/219 LAIDI 260/262 188 137 255/260 193/202 217

I had to abbreviate the names and scrunch everything together to get it in teh alloted space. . . . not sure how it will look when it posts! Where there is only one number. . . it means that the sire and the dam each contributed the same number.

Judy

[jamshundred]

Drat! These numbers just will not crunch nor come through right!

Let me try again!

. . . . BM1818 BM1824 BM2113 BRR CYP21 ETH3

LUKE 266& 188& 125& 260& 198& 219&
. . . . . 266 188 133 262 202 219

IVAN 262& 182& 125& 258& 193& 217&
. . . . . 266 188 137 260 202 217

LORE 260& 188& 137& 256& 198& 217&
. . . . . 266 188 137 260 202 219

LAIDI 260& 188& 137& 255& 193& 217&
. . . . . 262 188 137 260 202 217


Next time I will just take a picture! The format is not column friendly!

[jamshundred]

The above numbers are still a little bit askew. .but I've modified and modified and I cannot get them to line up precisely. It gives an overview at any rate!

Judy

[cddexter]

gol'darnit, Marion, how do you get that little box with the quote in it?

Back in the good ol' days, and they aren't that long ago, the only registration requirement was you filled in the paperwork, sent it in, and poof: the animal was registered (well, sometimes it took weeks or months to get the papers back, but in the end back they did come). The ADCA required ONE generation of purity, and registration was by pedigree only. It didn't matter what it looked like, what color it was, how tall or small, white or no, even horns, as long as the owner said these are the parents, it got registered, no questions asked.

I have somewhere the paperwork on an animal that, as Judy says, turned out to be polled but because there was no box on the reg. appl. to tick to say so, it was assumed to be horned. I think it was about 9 years later someone figured out oops, how come we have this polled animal? Ah, but there was nothing on the books to allow the Registrar to question or stop registration, even at that late date and certainly nothing that allowed her to de-register the cow and descenants (although there's another story in that....) so the assn's hands were tied.

I also have somewhere a letter from the then Registrar telling the President, and me as the Regional Director, that she 'had no choice but to register' a particular animal because we didn't have any means of preventing it, even though it didn't look like a Dexter (white face and socks).

It took a long time, and several really questionable registrations before the Board clued in, and a new clause was added that if the Registrar had questions, the owner could be required to provide proof of parentage. Only problem was, the Registrar was selective on how this got applied.

That's all water under the bridge, although the registry is still paying the price. These days, with better technology, and a more clued-in Board, we have sire inclusion and rules that allow the Registrar and Board to require proofs if something looks fishy, but that's now, and then was then.

If there was a problem, and now it's been fixed, what's to gain by going back and whining about how it 'should' have been----we're stuck with it, we've learned from it, and those particular problems won't happen again. c.