Some help with understanding TH and PHA

[hunt_britto]

Ok well I know most people I know like THF and PHAF calves. But I have seen a lot of people that like to use a carrier on a free calf. What do the genes do and why do some people not want to use frees on frees. I know you don't want to use a carrier on a carrier because you'll have messed up calves correct?

Thanks for the help

 

[jaimiediamond]

What I have found from browsing the planet is that carriers in the past had a very desirable phenotype. This would make them appealing as show calves.  With that being said I have seen some very attractive bulls recently being promoted that do not have a known lethal genetic defect.  This means that selection has got the phenotype without the defect

TH and PHA are both lethal genetic recessives which means if you breed THC to a THC you have a 25% of a deformed calf which has to be destroyed.  PHA-C x PHA-C could have a calf that is full of fluid thus is too large most could kill the cow delivering.  Meaning emergency c-section
PHA calf images view this link
http://www.dextercattleamericanlegacy.info/pha.html
For images regarding TH view this thread
http://www.steerplanet.com/bb/the-big-show/potential-genetic-defect-in-shorthorn-cattle/210/

 

[MDitmars]

Ok so the way i was told it works is fairly simple and see if spacing works right for this so you have your bull and cow both have imput into the calf obviously and the post above is right you have a 25% chance to get an active th or pha animal if you breed 2 carriers. here is how it works

T=Carry gene
t=non carrying gene

the punnetts square in the attachment shows you the options you will get.

So your options are TT which would be affected, Tt which would be a carrier (most likely shows no signs active) and tt which is free.

what people are doing with carriers to free animals is looking to get the 50% chance of being free all together or looking to sell show animals!

some bulls throw such good calves that they are worth either trying to get free calves or flat out just make sure you never breed them. Show animal usually don't matter on this because they will never be bred anyways they are going to be sold at fairs for a premium.

 

[BroncoFan]

I have wondered many times if one of the farms that are leading the show industry could produce a bull that is THF and PHAF and can consistently sire calves that will compete with the calves out of carrier bulls.

 

[hunt_britto]

Why do some people like THC bulls though? I have heard a couple people say THC's have more hair or bone but haven't ever seen it proven true

 

[BroncoFan]

Do you know any steers that have won any major shows that were sired by a THF bull.

 

[JTM]

Why do some people like THC bulls though? I have heard a couple people say THC's have more hair or bone but haven't ever seen it proven true

It has been trend I'd say in the last 4-5 years and maybe a little longer where major club calf producers, the people that know how to make the "great ones", are acknowledging that there are traits that are coming along with the TH and PHA carriers that put them above the rest. Is it superstition or just chance? Or is there really something in the genes? I would guess that it is something in the genes that allow these defect carriers to have more hair, more bone, and overall stoutness and volume. Many times club calf producers have these full sib embryo pregnancies or calves sired by carriers and one out of 10 is a great one. They know before they even test it that it is a carrier. Almost every time it seems. So now the club calf industry has reached a point where breeders are using the defect carrier status as a positive trait to have because it supposedly gives the calf some sort of legitimacy that it wouldn't have without the carrier status. In my opinion it's big money for such a very small number of people and the rest just flush it down the toilet trying to play a game they will never win...