DNA Tests

PeterO · Post by **PeterO** » Mon Dec 06, 2004 3:39 pm

Just received the DCS membership letter on fees. Can someone (Duncan?) tell me what the following will give me:
-Chondrodysplasia single test
-Chondrodysplasia duplex test
-DNA test
At £54 per cow it needs to be pretty good!

Peter

Duncan MacIntyre · Post by **Duncan MacIntyre** » Mon Dec 06, 2004 7:19 pm

A quick reply which may not be enough -

Single Chondrodysplasia test shows if the animal is carrying the bulldog gene or not. Its estimated accuracy is 1 in 1000, ie only 1 in 1000 chance of being wrong.
The Duplex chondrodysplasia test has only 1 in 1 million chance of being wrong.
DNA test would give unique identification that that is that animal, and if parents or offspring are done allows inconravertable parentage proof (or disproof!!).
I have done all those of my herd qhich were necessary to be sure that I no longer have the bulldog gene in the herd. Having done that I cannot breed a bulldog carrier unless I buy in untested cattle or use a carrier by AI or embryo transfer.
I do not need to test calves from those tested as non carriers.

Duncan

PeterO · Post by **PeterO** » Mon Dec 06, 2004 8:25 pm

Duncan

Thanks - your response was just what I wanted. It sounds like I need the duplex test - I will talk to DCS to establish the procedure

Peter

monica waltho · Post by **monica waltho** » Mon Dec 06, 2004 9:30 pm

DUNCAN,
Out of interest which of the tests did you use? I have about 20 cows + 4 bulls I should like to test but obviously depending which test I use there will be quite a difference in cost. I am expecting most of them to be bulldog free since I have mostly non short cattle.

Thanks Monica

Duncan MacIntyre · Post by **Duncan MacIntyre** » Tue Dec 07, 2004 12:20 am

Hello Monica,

I took the view that Shilton Pontius, a Woodmagic bred bull who is very short, was the one I had to be most sure of. My breeding policy involves line breeding using him. I used the Duplex test for him. The others I tested were ones I was pretty certain on appearance alone - one bought in cow Saltaire Drill, and other home bred ones which I really knew by comparison with other calves from the same cows were long. They just got the basic test.The few I had which I knew were "short" ie carriers, I did not bother to test as they were all males for beef, except my only two short legged cows. They are now gone - Cuerden Candy, 1989 born, just reached the end of the road this year and was culled, and her grand daughter Burnside Rosemary, was sold. So my breeding stock now have no carriers amongst them. Cuerden Candy was, I think, the only living offspring of the famous Canwell Buster, and though she was a very determined old swine I was very sorry to see her go. She was the spiitting image of a cow "Rosemary" pictured in the 1890 herd book mentioned elsewhere - I used to have an acetate somewhere which had the picture of Rosemary in 1890 alongside Candy about 100 years later, I must have a look for it. Sorry, I have got off the subject. I hope I have answered your question.
Incidentally I had no need whatsoever to test my two short legged cows as both had produced bulldogs in the past. Candy actually had two within one year, escaped and was caught by the short bull again when I had Woodmagic Black Bear waiting to see to her!

Duncan.

monica waltho · Post by **monica waltho** » Thu Dec 09, 2004 11:19 pm

THANKS DUNCAN,
I shall do all my bulls using the Duplex test,but I shall just single test my cows and restrict it inially to about 6 cows
I am curious about due to the increase in the cost of the test and the fact my membership has just gone up by £54!

Monica

Duncan MacIntyre · Post by **Duncan MacIntyre** » Thu Dec 09, 2004 11:53 pm

Hello Monica,
I wonder if the gremlins have been at your keyboard - the membership is up from £25 to £30. The £54 is for both the duplex test and DNA typing, and although it is a little bit up on same time last year the prices quoted then were approximate as it depended on the value of the pound against the euro, the dutch lab having to price it in euros.
I found that I did not need to test some of my cattle as their parents were already included - I would start by looking at your older breeding stock and testing those you want to breed replacements from, and as you work down into the heifers check if you have already covered both parents. I also left out two of mine as they had produced bulldogs so there was no point in testing. I think I tested 6 individuals to cover a herd of 14.
Incidentally I noticed that someone else had encountered problems with contamintation - very easy to get some foreign material in from other animals, dirt and bacteria and even yourself - I avoided the problem by using a blood sample which costs just the same to test, and I could do it myself as a vet, but even using your vet when they are on farm anyway should not add a huge amount to the cost - If I am on farm and take a blood sample as an extra I charge £2.35 includes tube, needle, etc.

Duncan

monica waltho · Post by **monica waltho** » Sun Dec 12, 2004 12:18 am

Hello Duncan
Well I think the gremlins may have got in my brain, but I should have said my overall membership costs based on
+£5 annual subs + £30 ( 15 x £2 no. of heifer registrations) + £45 (9 x £5 transfers) + £5 for herd survey = £95 extra on last years costs .It won't be quite that high because it is unlikely that I shall be buying in any this year.
Going back to DNA testing, I have only had one bulldog calf , since until recently I have had only one short cow - when I got her I had a short bull on loan and decided to risk it, I got away with it the first time so I tried again, not so lucky. I don't need to test her but I have 5 heifers by that bull so am interested to see if any of them are carriers. I shall test all my bulls, they are all non short but like you I have a bull who most people consider to be short when they see him .He is Woodmagic bred and I bought him as a youngster and he was definitetly non-short but if I were to buy him now and I did not know his breeding I would think he was short.

Monica

Paula Edwards · Post by **Paula Edwards** » Thu Dec 16, 2004 12:57 am

The information Australian Dexter breeders were supplied with, regarding the two types of DNA tests for chrondysplasia was, that the second test was for a mutation which appears to come from Meadow Park Charles.

Therefore, animals with no Meadow Park Charles in their pedigree, did not require the second test.

I don't know if it is different in other countries.

Duncan MacIntyre · Post by **Duncan MacIntyre** » Fri Dec 17, 2004 10:17 pm

The duplex testing and testing for the two genes are two separate issues, I think. As far as I know all are tested for the two genes, as one is as much guaranteed to produce bulldogs as the other. A single test for both will have an accuracy of 1 in 1000, and if we want to be extra sure we can ask for the "duplex" testing which involves a second test with a second person reading it. The chances of both being wrong would be 1 in 1000 x 1000, ie 1 in 1 million.

Duncan

Kathy Millar · Post by **Kathy Millar** » Thu Dec 23, 2004 6:25 pm

Could someone explain to me why, when taking hair samples for the DNA test, they have to come from the tail switch? I wish I could take them from a more "friendly" area as I have just found out I have to do this for registering a bull here in Canada and am not looking forward to getting kicked. Forget the blood test, I'm not expecting to have the vet over soon and he charges a lot of money to do anything and it is expensive to ship blood.

Kathy the reluctant cowpoke.

Duncan MacIntyre · Post by **Duncan MacIntyre** » Thu Dec 23, 2004 7:18 pm

The important thing is to have good fat follicles at the base of the hair. When you pull them, hold them up in the light and a wee bulb should be seen at the root of the hair. I would imagine many cattle would have sufficiently storng hair on the back of the neck.

Duncan

PeterO · Post by **PeterO** » Thu Dec 23, 2004 9:14 pm

Kathy

Why is it expensive to ship blood? I was going to get my vet to put it in a plastic vial (it coincides with a TB test) and ship it routine mail - have I missed something (like a DEFRA (Min of Ag) certificate or equivalent).

Peter

Duncan MacIntyre · Post by **Duncan MacIntyre** » Thu Dec 23, 2004 10:07 pm

I use conatainers purchased from Royal Mail for sending small numbers of blood tubes or pathological samples, cost somewhere in the region of £2 to send by first class post anywhere in UK and it was only a little extra to send to the dutch lab. It would have cost exactly the same to send hair. But of course the vet has to get to the cattle to take the blood sample, and for a one off job that would make it expensive. I charge £2 per blood sample for cattle bloods whilst on the farm anyway, includes tubes and needles and labels, and £4.70 per batch covers post, packing and reporting the results.

Duncan (not intended as a quotation or an advertisment, just some figures for comparison)

Kathy Millar · Post by **Kathy Millar** » Sun Dec 26, 2004 7:22 pm

Peter, it's just that I can mail the hair samples in an envelope at letter prices and blood must go in a "box" so the price goes way up in comparison.

Kathy