Benefits of DNA checks

[Rebecca]

I have been reading with interest all the debates on parentage in regards to polling, possible accidental crossing with other breeds etc. Also everyone seems to want to advoid the cost and inconvenience of DNA testing.

I am in Australia and our situation is a bit different. All our animals have to be DNA typed and Parent Verification done before registration can happen. We also don't have to register as early as you do - up to 18months for females, 3yrs for males. This has both good and bad points - we do "lose" some animals that are sold prior to registration (although we can register them as early as we like most big breeders seem to hold off to see how the calves grow on). Often animals are sold with the choice of registration of without - however it is very costly and time consuming to try to register an unregistered animal after the breeder has sold them - I wouldn't bother.

As far as the parent verification we have had reason to be grateful for it this season. A heifer we bought last year came to us in calf. She produced a lovely heifer calf for us and we duly sent the calf's DNA sample in with all the details (DNA case numbers, registration numbers) of her parents. I was rather shocked when it came back that the bull who we had been told sired her was not in fact the father - there had been no indication from the previous owner that the mother had been with any other bulls. A phone call to them found that she had in fact been running with 2 young bulls, but they had thought the bulls had been too young - obviously not - and that she had been bulling when put in with the older bull. As both young bulls were already registered it was simply an email to the lab to ask them to check both young bulls against our calf. One of them was definitely the father and our new heifer is now registered with all the correct details, no extra cost involved and minimal fuss, apparently it is not altogether uncommon - perhaps the most worrying point. If Parent verification had not been carried out she would have been happily registered with the wrong sire - simply because one can only go on the information one has.

On polling - the large proportion of polling in Australia probably comes from the fact that we have a grading up scheme (now closed to outside blood - no more 1st crosses can be bred). However, several AI bulls are polled and have a huge influence on the breed. We dehorn our calves, but several breeders are trying to create totally polled herds and polled animals tend to bring a premium at the moment (particularly here in Western Australia - maybe not so much elsewhere).

Isn't breeding animals fun!!

Best wished to all for the festive season

Rebecca (Australia)

[Inger]

I'm having to DNA a calf at the moment, because I put a cow that was supposed to be in calf, in with another cow which had a bull calf, to keep the cow company. I later observed some 'activity', so, although it may have been just play and the calf arrived within the allowed period, I'll still feel more confident after the DNA results come back.

Polled Dexters are here to stay. More small block holders prefer hornless animals out of safety concerns and because they don't like dehorning. I'm able to sell my surplus polled cows much quicker than many others' dehorned animals, simply because there is less chance of the new owner having to dehorn their calves. Many new to animal-care owners find dehorning distasteful and try hard to avoid it. So eventually I hope to have a completely polled herd. In the meantime I have to improve my female lines, so still need to use some horned bulls. Polling being only one feature that needs working on, when building up a herd.