Rat Tail breeding questions

Can someone explain rat tailed calves and how it plays out genetically. Is it a recessive gene?  When does it mainly play out?  Types of crosses that are more prone to it?
Been brought up by folks when I talk about breeding sim/angus cows to a char bull?  I've never had one, but sure don't want one.

Did a history seach and found some info.  But in short, I have some 1/2 bloods (black simmy x  black angus) that I was curious about trying a friend's PB char bull on.  But wondering about possibility / likelyhood of a rat tail?

The old Rat Tail syndrome all started with the old school YELLOW Simmentals. These were carrying the Diluter Gene. When crossed on Homozygous (Meaning full bloods) you would get a grey colored, almost hairless and curly calf. The tails would have almost no hair at all and would be usually very hard keeping compared to average.

When using a black simmi cow, she has most likely been sired by a non full blood angus cross type bull and would then not have that same diluter gene. Using a Charolais bull on her would most likely give you a smokey colored calf, but not a rat tail.

Remember, Homozygous Black Angus on a diluter cow will almost always give you a rat tail. Heterozygous black (Cross bred) on the same cow would most likely give you a smoke colored calf, but MAY not be rat tail, it could go either way.

Hope that is not too confusing -- best of luck

Terry

http://www.ncbi.nlm.nih.gov/pubmed/10340580

Analysis showed that the rat-tail syndrome is controlled by interacting genes at two loci. Cattle that express the syndrome must have at least one dominant gene for black color and be heterozygous at the other locus involved.

Do they have any calf crops from this bull with calves out of Angus cows?  If you do not see any rat tails then I wouldn't worry about getting a rat tail.  The rat tail problem is associated with some early Pie Rouge Simmental and Chianinas imports and has been mostly culled out due to complaints from bull buyers.

If you want to see what one looks like breed to Heat Wave ,His sons have been a lot better .....

You should know that charolais bulls have been siring rat tails long before simmys were imported to the US,

We used 15 units of MT/HLS Lead On on clubby type cows 5 or 6 years ago and had one rat tail calf born.  When I researched rat tails back then the article that Knabe posted was by far the best explanation that I found.  We fed ours out and put her in the freezer (to bad, if she had hair and a tail she would have been pretty nice).  She appeared to gain just fine and was tasty.

HGC said:

We used 15 units of MT/HLS Lead On on clubby type cows 5 or 6 years ago and had one rat tail calf born.  When I researched rat tails back then the article that Knabe posted was by far the best explanation that I found.  We fed ours out and put her in the freezer (to bad, if she had hair and a tail she would have been pretty nice).  She appeared to gain just fine and was tasty.

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How did you like those lead on calves? How did he breed for u? Moderate the calves or were they stringy? Thanks

Gargan said:

HGC said:

We used 15 units of MT/HLS Lead On on clubby type cows 5 or 6 years ago and had one rat tail calf born.  When I researched rat tails back then the article that Knabe posted was by far the best explanation that I found.  We fed ours out and put her in the freezer (to bad, if she had hair and a tail she would have been pretty nice).  She appeared to gain just fine and was tasty.

Click to expand...

How did you like those lead on calves? How did he breed for u? Moderate the calves or were they stringy? Thanks

Click to expand...

I thought he would work on some TH carrier cows to get some smoke show calves, but they were really plain, very poor hair, average bone, average muscle.  The steers were at best, average county fair steers.  If you wanted to use him, it would be to make smoke cows, and then breed them clubby.  They had plenty of body, easy feeding and were real sound.  The best one we had was out of a heat seeker x angus Th carrier cow.  That heifer was always competitive, but she has had 3 calves, all steers and all of them went in the feedlot, just to plain.

Thanks everyone. I think we are good to go.  Appreciate the comments.