Question about rattails

[Rosielou]

I have a couple questions about rattails and I can't seem to find what I'm looking for on google or in old posts so I thought I would ask here. I had a char x momma(I am thinking char x brangus or char x beefmaster) cow bred to black angus and the bull calf ended up rattail. I got curious and started researching. I know this is common in this cross as well as simmental. I also know that they sometimes don't grow as well and might get docked at the salebarn, but I also read that they can be good momma cows, but should be culled because they carry that gene. But what causes this? I got to wondering about it and why it happens. It is as simple as two genes coming together and creating that gene of ratty hair growth and a tail lacking a switch? I read that rattail is dominant and will be expressed usually, so could the bull that sired this calf be a recessive carrier of that gene? Sorry if I sound uneducated on this subject, I'm kind of confused. My Grandfather didn't know for sure when I asked him, he just knew it was common in this cross. I understand it's because of the diluter gene(yellow momma cow) and you cross it with black(black angus bull), but I don't understand why it happens. Is it as simple as these two colors coming together and they create these defects? Should I refrain from this cross in the future? Thanks in advance. Genetics fascinate me so I'm always wanting to know all I can.

The calf in question. This is the cow's second calf, we had to pull her first one(95-100 lb calf on a heifer!) and it suffocated before we could get it out.

A good picture of the momma(Except the tail, sorry) during summer. I personally liked her length.

 

[Bigfoot]

This doesn't answer your question, but I have several char cross cows, and have had my fair share of wire haired calves. I have used many different bulls with the same result-------Brangus, char, and gelbvieh come to mind in the last 3 years. All produced rat tailed calves.

 

[Putangitangi]

I have a 5-yr cow, her 2yr daughter, both rat-tails. I live in a warm climate though and the calves get grown out in the same sort of area, so it isn't much of an issue for me or them. This family happens to be a growthy lot, so I kept them, despite the defect. Because it's dominant, these two will throw 50/50 rat-tail and normal. Both have black straight-haired calves this year - they're mostly Angus, with a bit of something about four or five generations back.

It's a multi-gene condition. I looked up its inheritance once and understood it, but I couldn't tell you how it works without going through the process of understanding it again for myself now. The mother of my original cow was a red/white-face with probably some Charolais in her mother, Hereford sire. The rat-tails have all had black Angus sires.

 

[fitz]

I'm like Bigfoot, I can't explain the scientific reasoning. My experience with the rattails began when I started using an angus bull on straight simmental cows. It's a result of the British/Continental cross as I understand.
Over the years any cow that seemed to produce multiple rattail calves I culled out. Hadn't had one for years and seemed to be a non-issue until this past fall. My old boss cow, which had never given me one, made her contribution. I'd have to look back, but she has had well over 10 calves before this rattail popped out. It will grow as well as the others. In fact he may be larger than some. However, he most likely will be docked at sale time.
In my situation I think I'll see a significant reduction of these calves as I move closer to a SimAngus herd of momma cows.

fitz

 

[Red Bull Breeder]

The old type Sim cows is where I have seen the most rat tails come from. Char x cross cows only seem to throw them if there is a little ear in the mix.

 

[Rosielou]

Hm, this is interesting. So it comes from the diluter gene, which charolais and sims carry? I'm curious as to why it causes the defects. If I continue to breed this cow to a black angus bull, will she always throw rattail calves or sometimes not? Or 50/50? Would it be wise to keep heifers out of her if they are rattail? I have no problem really keeping them, but is it profitable since they will be docked at the sale? I've seen them before but I've never had any real experience with them, and we've never had one born into our herd. I guess we had gotten lucky. Thanks for the replies!

 

[fitz]

Hm, this is interesting. So it comes from the diluter gene, which charolais and sims carry? I'm curious as to why it causes the defects. If I continue to breed this cow to a black angus bull, will she always throw rattail calves or sometimes not?
No.
Or 50/50?
My experience has been much less than that. I guess it depends on the cow.
Would it be wise to keep heifers out of her if they are rattail?
I don't. I never kept a cow that gave me more than one. I love the cross but don't care to see a short haired calf all bowed up when it's 15 degrees and snowing while the rest are standing with a couple inches of snow on their backs.

I have no problem really keeping them, but is it profitable since they will be docked at the sale? I've seen them before but I've never had any real experience with them, and we've never had one born into our herd. I guess we had gotten lucky. Thanks for the replies!

 

[AudieWyoming]

It has been several years since I have given this any thought so my recollection is not 100%. I do know its caused by the diluter gene in the Simmental and Charolais breeds (maybe others) X the black color gene. I have seen diluters in Hereford cattle but that could have been from Simmental influence. The Angus breed does not carry the diluter gene but the black color will cause the cattle with the gene to express itself.

My first knowledge of it came in the '70s when the feedlots really liked the smut colored Char-Angus calves, but the buyers would reject any that looked like a possable rat-tail. I remember in the 80's, 90's when the Simmentals were turning black many breeders just knew it had to come from the Angus bulls because they had been running the red cows for years and it had never shown up. The diluter gene was prevalent in Simmental blood lines at the time, but I believe they have bred away from most of it now. @

 

[Rosielou]

Just found out today when I was feeding cubes that the calf is blind in his right eye- it's white/blue and milky. Guess he was born with it because it's happened before a few years ago. No other visible defects. Guess I'll be taking a hefty dock on this one, but atleast I'll get something!