for you genetic gurus

[cypressfarms]

I've got a couple of questions for the genetic gurus out there:

I have a white (with some black spotting) LONGHORN cow. (Before the obvious question; my kids like the "color", and they only cost me $250, so I bought several longhorn heifers a few years back - I culled the bad ones and have two left that are good mamas.) This longhorn cow has had three calves on my farm. Bred to my previous angus plus bull, she had two solid black calves and one that looked like cookies and cream ice cream - black and white all around. White spotted moma in question is obviously horned. This year's calf if a black heifer, who's growing nicely. So here are the questions.....:

1. If I retain this black horned heifer calf, what color is dominant for the calf's offspring?

2. This heifer will be horned; if she's bred to a polled bull, what's the chance that the offspring will be polled?

I know the "normal" answers...Black is dominant, and breeding a polled bull to a horned cow will result in a polled calf; BUT with longhorns everyone knows all genetic bets are off. So IF this heifer is retained, what to expect?


Here's the mama, and despite that "look", she's very docile. This pic was taken just after she calved:

 

[cow pollinater]

Black is dominant as a base color but the spots are a different gene. Geneticly you will get a black calf but it might also have spots. :lol: Think of breeding roan shorthorns to angus, they come out black based but the roan is still there.
As far as horns, my concern would be the angus plus bull. The plus part of the equation has horns in it's heritage.

 

[Red Bull Breeder]

Unless the bull is homo polled you can still get horns.

 

[Karin]

Solid is dominant over spotted. If the heifer is hetero solid her offspring could be either spotted or solid. Her sire may have some spotting in his genes (since you did say he's "angus plus"), but the solid dominance from the sire was carried over the spotted recessive from the dam, making the heifer have a genotype solid-spotted. If she's bred to a homo-solid bull, all her calves will be solid. If she's bred to a hetero-solid bull, she has a small (~25%) chance that she may have a spotted calf. If the bull's homo-spotted, make that a ~50% chance her offspring will be spotted.

The fact that the heifer is horned makes it obvious that her sire was hetero polled. It's that "plus" part as pollinater mentioned.

As for colour, unless she's carried some sort of heterozygous red gene from her sire and/or dam, it's hard to say. Chances are good that all--or most, rather--her calves may turn out to be black.

Good link to look at: http://www.backyardherds.com/web/viewbl ... r-genetics

 

[cypressfarms]

The "plus" of the angus plus is just a way to describe a cross between an Angus and a Brangus, or two angus pluses - some people call them other names, but he is registered. On this particular bull, for the previous six generations (if memory serves me correct), his heritage was not only black but polled as well. This is the first offspring of the said bull that has had horns. I believe that the horn part came in with the longhorn. My gut feeling is that with longhorns all bets are off for color and horns, but ofcourse I could be wrong - it wouldn't be the first time. This angus plus bull is not some woodshed / inbred mutt, but a well documented sire with epd's and a documented heritage.

 

[Caustic Burno]

The "plus" of the angus plus is just a way to describe a cross between an Angus and a Brangus, or two angus pluses - some people call them other names, but he is registered. On this particular bull, for the previous six generations (if memory serves me correct), his heritage was not only black but polled as well. This is the first offspring of the said bull that has had horns. I believe that the horn part came in with the longhorn. My gut feeling is that with longhorns all bets are off for color and horns, but ofcourse I could be wrong - it wouldn't be the first time. This angus plus bull is not some woodshed / inbred mutt, but a well documented sire with epd's and a documented heritage.

He could still have a horned gene crossed with a cow with a horned gene.
I know the composites are supposed to be standardized, just I am not totally sold on what is still left in the DNA wood pile.

 

[cypressfarms]

He could still have a horned gene crossed with a cow with a horned gene.
I know the composites are supposed to be standardized, just I am not totally sold on what is still left in the DNA wood pile.

Well with black charolais and beefmasters and black herefords, you have a point there. It's getting harder and harder to trust some of the hardfast rules that used to be cast in stone.

 

[Taurus]

It's tough to knock the longhorn colors off. My buddy bred his longhorn & roping cows to black angus bulls and he got mostly black calves with few skunks and spotted calves and even 1/16 longhorn cows has colors on them.

 

[Caustic Burno]

Where is Dun when you need him? Sleep in a deer stand most likely.

 

[Fire Sweep Ranch]

Homozygous polled bull will always throw polled, regardless of the horned status of the cow. All resulting calves will be heterozygous polled from that heifer, meaning they are polled but will carry the horned gene, when bred to a homozygous polled bull. Her sire obviously has horns in his pedigree (heterozygous polled), or the resulting calf is not his. Now, if she has Zebu influence, all bets are off! Read this article, it is pretty good. Towards the bottom is the reference to the African influence and Zebu.
http://www.britishsimmental.co.uk/resea ... dness.html

Now scurs are a different gene story! Get those in our breed now and then.

 

[Workinonit Farm]

Where is Dun when you need him? Sleep in a deer stand most likely.

I was wondering the same thing. I'm surprised he hasn't chimed in by now. Maybe he's just sleeping....comes with age ya know. ;-)

Katherine

 

[Red Bull Breeder]

A longhorn cow will make a liar out of a homozygous polled bull now and then. The angus plus bull could still carry the horn gene.