"Do you know whether testing of AI bulls has been started yet in England?" I wouldn't know Marion but if people want to sell semen then they are going to have to test!!
From what has been said Liz, and having seen the fairly horrific video of a full term waterbaby calf being removed, then on the basis that you couldn't exactly miss it then going full-term must be quite unusual by the sounds of it.
If they are aborted early and are tiny then you'd only notice by having barren cows. We couldn't really miss anything bigger here because we don't have big predators and if something dies in a field it gets swarmed by rooks which is a "dead" give-away (sorry for the pun, I wonder if that is where the saying came from?).
If bulls are tested and clear, then I assume there is no need to test cows because that's the end of the problem?
Then all bulls would need to go on being tested ad infinitum.
If bulls are tested non-carrier and cows are tested non-carrier, then that is the end of the problem,
and the end of any further need to test any of their descendants, ... until we find another lethal.
Margaret
The cost of testing everything would be hard to convince people like me. Especially if you have 50 cows and 1 bull! Put yourself in my position as an example, I had literally never heard of this condition until I read about it on a forum last year. We have had very few barren cattle that haven't had a fairly obvious reason like being hugely overweight.
If there had been numerous occurrences of the condition then surely I would have something, but it is just a complete blank.
Another leading question is why carry out tests and eradicate this condition and yet at the same time allow, and even promote, the breeding for chondrodysplasia, which to me seems just as bad?
Until such time as PHA has been positively identified in a related UK family, how would anyone know Aldebaran Priapus isn't a mutation?
It seems to me that all breeders should be aware of what is happening in the rest of the Dexter world, but way too early to freak out about a condition that may not even be there.
The worst scenario would be a cover-up, or mis-diagnosis, for or against.
Margaret.
I agree Margaret, on both counts. As far as wholesale testing in large herds in Canada, the same concern as yours, Clive, was raised over here. But testing doesn't necessarily mean the entire herd needs to be done but rather establishing the status of the bull used and then looking at family lines and checking the status of the eldest cow of each line. PHA doesn't skip a generation so once two pedigree links are found to be free, dam and sire, then their progeny would also be free of the mutation. That is why all the interest in Wheatear's status here. If the mutation did indeed start with Priapus then a lot of our pedigrees would be automatically free and not require testing. Liz
I agree with Margaret, but the difficulty is knowing whether you need to test. My last posting crossed with yours Liz hence I didn’t read your second till I had posted.
Our testing is expensive; I think the first priority is all bulls, which is planned. While it is true that early cases could be missed the presence became evident very quickly in the case of Australia and the States. In the former it was known well before a test was established. I knew of its existence over there at least by ’07 but it hadn’t reached Australia at that point.
Beryl (Woodmagic)
Hi, Posting this for Carol D:
"I tried to rejoin the English site, but my server seems to truncate the address and I can't get it to work. I saw the posts regarding pha, and thought some additional information might prove useful. Perhaps you'd post for me?"
Jon Beever, the American researcher who was looking for chondro at the same time as Julie Cavanagh (in AU), received many samples from American breeders. However, when Julie found the locus, and Jon tested his samples against the locus, he found a lot of the samples were not homo chondro, and so were not 'bulldog' calves, even tho' they'd been sent to him as such. Recently, when he was looking for the hydrops locus in Shorthorns and Maines, he remembered the non-chondro Dexter samples, and ran them against his hydrops locus. He found a different hydrops mutation, unique to Dexters (83 missing base pairs instead of just the 4 found in the other two breeds*) and all the non-chondro Dexter samples were positive for the Dexter hydrops mutation. ah ha! *or was it 84 and 3. can't remember...
This indicates that the hydrops had been around, and fairly common, in American Dexters for some time, but has been mis-identified. As has been pointed out, SO FAR, all carriers of hydrops descend from Aldebaran Priapus, an early AI bull from Canada, exported to most countries as both semen and sire of embryos. His sire tests as not a carrier, which brings his dam into question. The dam's location is known, and if current testing of live animal descendants doesn't resolve the issue soon, there is a plan afoot to exhume enough of Woodmagic Wheatear to have the DNA extracted and tested for pha (doing parentage verification along the way to still any questions or doubts).
Either it is a mutation starting with Priapus, or it came into Canada with Wheatear. As Beryl points out, she has not had any evidence of pha in her own herd, but Wheatear is actually 1/2 Doesmead, and there is a possibility that if Wheatear IS a carrier, it might have come down through that side of the pedigree. This possibility opens up a whole new avenue of research, and testing, and is why it is so important to identify earlier sources, if they exist.
There is no point guessing. All that does is create stress and point potential fingers. It sounds like Duncan has his finger on the pulse; I'm interested to read the official report he says is due out soon.
The DCAI paid to have all AI bulls tested for pha, and published the results, including a letter to all the other Dexter associations. Several Americans privately tested and paid for, and then shared the info, for most of the U.S. AI bulls (except for some very early ones they can't find semen for), and in so doing, covered most of those available in Canada. The few Cdn ones not included have been privately tested and paid for, and the info shared, providing a complete list for that country. Those American results can be found within the pedigree information on the ADCA site, dextercattle.org (click on the pedigree then scroll down to the pha status, and that will bring up the list of all tested animals, to date). The other American association, the PDCA, does list tested animals too, but you have to be a member to access the info.
Anyone interested in the pedigree info can check it out on the clrc.ca website, or on the dextercattle.org website. Regards, Carol C.
Hi Carol, just in case there are Canadians, CDCA members, reading this, there are a couple of AI bulls, publicly available whose status hasn't been shared. But there is a list the rest and their results on our Association private chat site. Just wanted to clarify that Canadians should still request the PHA status of any AI bull, if they are not sure. Thanks, Liz
We have recently had some PHA testing done and have had a carrier result returned for one of our PB cows which started with a Jersey X being inseminated with Trillium Chabotte. It has come through 5 generations and so my advice to people is to test anything with Alderbaron Priapus, Trillium Chabotte in the background, no matter how far back.
Surely you can send hair samples form the Uk to Australia for testing?
The sooner we establish which animals are carriers and not register any progeny from carriers unless they are tested free the sooner we will started to address the problem. Who cares where it came from, our who has it in their herd, so long as we can manage the problem and not increase its prevelance in our herds.
Some of us are lucky and we choose to manage the issue, join us in being responsible breeders and do your bit by testing your at risk animals
"Surely you can send hair samples from the Uk to Australia for testing?"
We can send hair samples for gene testing (marbling etc), so the answer must be yes. What's the cost Marg? Because in the UK/Europe everything has a tendency to be double, triple and even more than Oz and America.
It would be easy with the DCS database to produce a list of all potential animals related to those lines and to notify the owners.
"Surely you can send hair samples from the Uk to Australia for testing?"
We can send hair samples for gene testing (marbling etc), so the answer must be yes. What's the cost Marg? Because in the UK/Europe everything has a tendency to be double, triple and even more than Oz or America and that could be the biggest stumbling block. The Americans pay a quarter of what I have been quoted from Europe.
I was unaware that any Priapus or Chabotte straws ever went to UK, but if so only their descendants need be tested. Until any other positive case has been identified in UK, it would seem to be a bit hasty to start testing yet.
If ever a case is identified in UK then that would be the time to begin testing the oldest possible ancestors of that line, so as to avoid un-necessary testing of subsequent generations.
All the bulls on the Australian AI semen catalogue have been tested, so in our own case we only had to test 2 at-risk females, 2 matriarchal females from archived DNA, and 2 privately imported semen samples.
Testing of those 6 animals gave PHA-free status to the 60 head of cattle at home, and to all those we have sold.
Margaret.
Our DNA testing for PHA from a hair sample costs $49 AUS, sorry don't know the exchange rate. Contact the University of Sydney via the web once in their site search PHA, Marie and Imke are very helpful.
If PHA goes back further than Alderbaron Priapus through his dam, which is unproven at this point. The bloodlines are definately present in the UK. Testing will have to be done on the oldest animals first. I would recommend carefully looking at bloodlines to give as many free by inheritance as possible by testing the least number. Of course if you have a carrier it is not the end of the world, just a matter of not registering any further carrier calves. And testing is the only way to achieve this.
That's £25.50 approximately which is almost double the American figure at current exchange rates. The British Pound is weak at the moment against both currencies, so the comparison is fair and also it means that the cost of testing in the US os OZ would get even cheaper still.
At normal exchange rates which will presumably return, the cost of testing in the USA would be less than now at around £12.00 (for a batch) + postage.
Cost is critical because if it's £25-30 a head or more, it's going to have limited take up. But at £12, we would test our not-for-beef stock, starting with the oldest, just to see the results.
then going full-term must be quite unusual by the sounds of it.