Homozygous polled bull and scurs

Help Support CattleToday:

Dubcharo

Well-known member
Joined
Sep 29, 2012
Messages
247
Reaction score
92
Location
Quebec, Canada
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.
 

Nesikep

Well-known member
Joined
Dec 13, 2008
Messages
16,679
Reaction score
1,190
Location
Lillooet, BC, Canada
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.
 

Nesikep

Well-known member
Joined
Dec 13, 2008
Messages
16,679
Reaction score
1,190
Location
Lillooet, BC, Canada
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?
 

Caustic Burno

Well-known member
Joined
Sep 26, 2004
Messages
27,137
Reaction score
1,980
Location
Big Thicket East Texas
Dubcharo":170z1ucp said:
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.
 

Putangitangi

Well-known member
Joined
Feb 28, 2007
Messages
906
Reaction score
7
Location
Aotearoa - New Zealand
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.
 

SPH

Well-known member
Joined
May 5, 2013
Messages
646
Reaction score
29
Location
Iowa
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.
 

Nesikep

Well-known member
Joined
Dec 13, 2008
Messages
16,679
Reaction score
1,190
Location
Lillooet, BC, Canada
Putangitangi":3unaazc5 said:
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?
 

Putangitangi

Well-known member
Joined
Feb 28, 2007
Messages
906
Reaction score
7
Location
Aotearoa - New Zealand
Nesikep":rfy2gt5p said:
Putangitangi":rfy2gt5p said:
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.
 

Nesikep

Well-known member
Joined
Dec 13, 2008
Messages
16,679
Reaction score
1,190
Location
Lillooet, BC, Canada
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
 
OP
Dubcharo

Dubcharo

Well-known member
Joined
Sep 29, 2012
Messages
247
Reaction score
92
Location
Quebec, Canada
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 :)).
 

Putangitangi

Well-known member
Joined
Feb 28, 2007
Messages
906
Reaction score
7
Location
Aotearoa - New Zealand
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.
 

VirginiaCattle

Well-known member
Joined
Oct 15, 2014
Messages
69
Reaction score
0
Location
Southwestern Virginia
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.
 

Muddy

Well-known member
Joined
Feb 9, 2015
Messages
2,635
Reaction score
43
Location
Cold place!!!
VirginiaCattle":2zu9shh1 said:
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.
Seen more scurs in many Angus sired males but only seen a scurred cow....
 

Jeanne - Simme Valley

Well-known member
Joined
Dec 9, 2004
Messages
12,310
Reaction score
1,204
Location
Central Upstate New York
VirginiaCattle":2guh186d said:
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.
You are incorrect. Females MUST inherit two scur traits to be expressed.
"Presence of scurs (typically small, movable, hollow pseudo horns) only occurs in heterozygous polled animals (carry one polled allele and one horned allele, Pp). Scurred is also a sex linked trait meaning the genetic inheritance is controlled differently in males than females. Scurs is a dominant trait in bulls meaning bulls only need one copy of the scurred allele to have scurs. Scurs is a recessive trait in females meaning a cow needs to have two copies of the scurred allele to display the phenotype (see below for possible genotypes and resulting phenotypes for the horned, polled, or scurred conditions)."
https://asascienceblog.wordpress.com/20 ... ced-trait/
 

VirginiaCattle

Well-known member
Joined
Oct 15, 2014
Messages
69
Reaction score
0
Location
Southwestern Virginia
Jeanne - Simme Valley":1i94gr0l said:
VirginiaCattle":1i94gr0l said:
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.
You are incorrect. Females MUST inherit two scur traits to be expressed.
"Presence of scurs (typically small, movable, hollow pseudo horns) only occurs in heterozygous polled animals (carry one polled allele and one horned allele, Pp). Scurred is also a sex linked trait meaning the genetic inheritance is controlled differently in males than females. Scurs is a dominant trait in bulls meaning bulls only need one copy of the scurred allele to have scurs. Scurs is a recessive trait in females meaning a cow needs to have two copies of the scurred allele to display the phenotype (see below for possible genotypes and resulting phenotypes for the horned, polled, or scurred conditions)."
https://asascienceblog.wordpress.com/20 ... ced-trait/

I know what the 1970's literature says on the subject.

My question is: if it takes 2 copies to express in a female, and I have several females in a family line expressing, why aren't their steer mates, sires, or 3/4 female cousins ending up with scurs?
 

VirginiaCattle

Well-known member
Joined
Oct 15, 2014
Messages
69
Reaction score
0
Location
Southwestern Virginia
Basically I'm breeding 200 cows a year to registered Angus.

I keep replacements all from an AI bull I usually rotate every 2 years.

If you're correct and popular Angus bulls actually have scurs, then it would quickly spread through my herd and others.

The fact that it is only in two maternal lines out of 200 cows, I think the science is incomplete.
 

Muddy

Well-known member
Joined
Feb 9, 2015
Messages
2,635
Reaction score
43
Location
Cold place!!!
What kind of your cows, VirginiaCattle? Not saying you are wrong, but Jeanne is correct on scur genes. I knows our herd carries scur and horn genes and I only have one scurred cow but I always have more scurred steers. I don't think I ever had another scurred female after that scurred cow. To be honest scurred females are not common in this region.
 

Latest posts

Top