Page 1 of 3

Homozygous polled bull and scurs

Posted: Wed Jul 11, 2018 10:23 pm
by Dubcharo
Can an homozygous polled bull give scurs to his progeny even though the cow have no gene for scurs? I know that a cow need 2 scurs genes to express scurs on her head and if she have just one gene she didn't show scurs.
If a scurs cow can have an homozygous bull calf he will carry at least 1 scur gene and still be smooth polled.

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 12:16 am
by Nesikep
I think if the calf is a bull, it only needs one scur gene to express them, if it's a heifer, it needs both to express them... Read that somewhere recently.

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 12:20 am
by Nesikep
If the cow is homo polled and hetero-scur, and bred to a homo polled non scurred bull, you should end up with 50% of bull calves with scurs and 0% scurred heifers (though 50% will have one set of scur genes)
If the bull is hetero scurred and bred to the same cow, you'll have 25% homo scurred, 50% hetero scurred, and 25% non scurred calves.. so of those calves, you'll have 75% of the bulls expressing scurrs and 25% of the heifers

Clear as mud?

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 12:23 am
by Caustic Burno
Dubcharo wrote:Can an homozygous polled bull give scurs to his progeny even though the cow have no gene for scurs? I know that a cow need 2 scurs genes to express scurs on her head and if she have just one gene she didn't show scurs.
If a scurs cow can have an homozygous bull calf he will carry at least 1 scur gene and still be smooth polled.



Yes and from what I have read over the decades the elimination of it is deemed impossible.
PP =polled
Pp = polled possible scurs.
pp = horned
This is my understanding of it after breeding polled Herefords for several decades.

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 1:09 am
by Nesikep
DNA testing could help with that... but is it really that big a deal? Problem is just that the horns mask the scurs

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 6:08 am
by Putangitangi
Yes. I think that's your answer.

I have purebred, smooth-polled Angus bulls (they're all like that, of course) but having had at least two scurred cows in my herd in the last few years, I have to conclude that some of my bulls have carried scurs. The cows who have scurs must be heterozygous for horns for the scurs to show. That is possible, having been bred up from a mixed lot.

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 8:11 am
by Ky hills
In Charolais, it was very common to have scurred calves from polled cattle

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 9:30 am
by SPH
It's possible, we have a calf this year to prove it too. Cow is a polled cow but her sire side of her pedigree is all horned so we try to breed her to homozygous polled bulls as she likely would have a horned calf if mated with a heterozygous polled bull. Her calf this year is sired by a homozygous polled bull and noticed when we worked cattle prior to turning out on summer pasture he had some scurs starting to pop out. Homozygous polled only means that bull won't sire a horned calf but it doesn't guarantee you won't gets scurs too.

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 1:34 pm
by 76 Bar

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 1:51 pm
by Nesikep
Putangitangi wrote:Yes. I think that's your answer.

I have purebred, smooth-polled Angus bulls (they're all like that, of course) but having had at least two scurred cows in my herd in the last few years, I have to conclude that some of my bulls have carried scurs. The cows who have scurs must be heterozygous for horns for the scurs to show. That is possible, having been bred up from a mixed lot.

So with cows they have to be hetero-polled and homo-scurred? Homo-scurred is not enough to make them show it?

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 4:34 pm
by Putangitangi
Nesikep wrote:
Putangitangi wrote:Yes. I think that's your answer.

I have purebred, smooth-polled Angus bulls (they're all like that, of course) but having had at least two scurred cows in my herd in the last few years, I have to conclude that some of my bulls have carried scurs. The cows who have scurs must be heterozygous for horns for the scurs to show. That is possible, having been bred up from a mixed lot.

So with cows they have to be hetero-polled and homo-scurred? Homo-scurred is not enough to make them show it?

That's my understanding of the genetics. That's why I see so few of them amongst the steers, who ought to have them from their invisibly-scurred sire: their mothers must be all homozygous polled.

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 4:41 pm
by Nesikep
Doesn't mean much, but both my bulls were scurred, come from a horned cow and homo polled gelbvieh bull, I've never had a scurred cow though

Re: Homozygous polled bull and scurs

Posted: Thu Jul 12, 2018 9:18 pm
by Dubcharo
Thanks for the reply everyone. It comforts me in my beleives. An homozygous polled bull can have a calf with scurs with a polled cow (she can have a scur gene hidden) that's what most people give as answer when asks, but an homozygous polled bull with a cow clear of the scur gene can have a scurred bullcalf (from the sire) it's a step difficult to take for some people! (not a lot of people have the time or the will to thing about that also :-)).

Re: Homozygous polled bull and scurs

Posted: Fri Jul 13, 2018 4:17 pm
by Putangitangi
I was initially led astray by the assertions of Angus breeders that there were no scurs in pedigree cattle, certainly not in their valuable bulls. But my sires are sired by their bulls over many years and none of my bulls have scurs either. The fact that a couple of my cows do is impossible without their bulls having contributed the genes.

Re: Homozygous polled bull and scurs

Posted: Sat Jul 14, 2018 9:28 pm
by VirginiaCattle
I question the sex-linked logic.

I've had two cows with scurs and every daughter retained has them.

Registered Angus sires. In my experience, it is a dominant trait in females.