Stallions - Herda Carriers

If I get too many requests I'll try to get the list in a form I can attach to those interested. My printer doesn't scan, but I can take digital photos when my friend returns my camera.

I'm not sure I understand your question.

Breeding non carrier to non carrier results in 100% "clear".

Breeding carrier to non carrier results in 50% carriers and 50% "clear".

Breeding carrier to carrier results in 25% afflicted, 50% carrier, and 25% "clear".


ETA: As most people know, I am opposed to breeding HERDA carriers...

That doesn't match the data that I was reviewing on a medical website. What website were you researching? Also the website I was looking at showed that some will be affected meaning they are afflicted with the disease and then it mentioned a percentage that would be carriers meaning they could pass it on. I'm curious, is it possible for an afflicted horse to not be a carrier or do the 2 go hand in hand?

I also read that a carrier can be bred to a non-carrier and only have a percentage of carriers. I'll go back and find the link if I can.

I really don't know much about the mechanics of HERDA so I'm actually asking questions out of pure interest.

For opinion purposes I want to add my caveat:

I do not believe in breeding a known carrier of any genetic disease or defect. There are plenty of horses with the same bloodlines and attributes that are "clean".

Farmpony - Face's math is right. He didn't get that from a website. It's simple genetics.

NdAppy - Just to let you know, I read your response as "You are stupid". T

Anyway,
I have a basic understanding of genetics but hold no degrees in science or biology.

This is a qoute from the below site:

For horse breeders, identification of carriers is critical for the selection of mating pairs. Breedings of carrier horses have a 25% chance of producing an affected foal. Breedings between normal and carrier horses will not produce a HERDA foal although 50% of the foals are expected to be carriers.

Horse HERDA

This website below is the one that has me confused. It states that a carrier and a non carrier will give you 50% carrier, 25% afflicted, and 25% clean. The way they broke it out it appears that the 25 percent afflicted is in it's own group. Does that mean they are afflicted but not carriers?

Of course this site may be a bad reference because it shows if you take a carrier and breed it to a non-carrier then you get 100% carriers but that's not true.

http://ckmobileequine.ca/articles.html

Never said you were stupid nor was that implied in my post.

Afflicted horses are carriers. They have two copies of the HERDA gene where carrier (non afflicted carriers) only have one.

The math on that site is exactly the same as what Face stated. Carrier to carrier is 25% clear, 50% carrier, and 25% afflicted. Always will be.

Assuming this is what you are talking about here -


The Punnett squares are correct. The one on the right, if that is what has you confused, is afflicted (horses with two copies) bred to a non-carrier. That will give you 100% carriers of the disease.

ETA their little thing at the top doesn't match their squares. NH and HH are actually used in reference to HYPP. HERDA is N/HRD or HRD/HRD.

That is how I would read it. Afflicted are carriers and also stricken with HERDA.

I still read it that way and I still feel that's what you were implying.

That same site shows that a herda horse and a normal horse would be 100% carrier which is why I question the data on that particular site.

I'm asking questions because I don't know answers or I am looking for clarification or even to ensure that what I think is correct, is infact, a true statement.

Thank you.

That was my question. So an afflicted horse is both carrier and suffering from the disease where a carrier only carries the gene and will only pass it on partially.

Now I understand.