# Polled breedings



## Lightfoot Packgoats (Dec 12, 2008)

Someone asked me about polled to polled breedings and what can go wrong.

The most common thing folks worry about is producing a hermaphrodite (freemartin, a female goat that is not quite female can cannot be bred). This does happen, occasionaly, if I quote a percentage someone will tell me it is more or less so I'll quote what I heard from my friend who breeds dairy goats and runs over 3,000 goats, I think she milks 1,500, she has a commercial dairy.

She told me that "they" say it is about 10%, but her experience in breeding polled to polled is it happens less than that. Her numbers must be pretty good because she does so many breedings and likes polled goats because it saves her time with the dehorner.

Then she took me to show me a horned doe who was a hermaphrodite and said, "Explain her!". Uh, say what? It does, happen apparently. That doe never did take in any breeding and just before she sold her the doe died for some reason,they posted her, sure enough her birth canal ended in a blind sac and the uterus was not found.

You can also get a himaphrodite from these breedings, they just sort of come out "wethered", the testes never grow, they never go into rut and they never have to be castrated, but like all early wethers they would be at a higher risk for UC as their urethra does not mature and grow to its full diameter.

Charlie Goggin
Lightfoot Packgoats


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## sanhestar (Dec 10, 2008)

Hello Charlie,

if you do the "pure math" of polled to polled breeding, you'll end up with 25% hermaphrodites:

P= polled, dominant
p= horned, recessive

polled goats that aren't hermaphrodites carry one recessive horned gene, horned goats are pure "pp".

So, if you breed polled with polled:

Pp x Pp

split that down to single chromosome sets:

P p P p

you get over time:

two sets Pp - polled, normal sex
one set pp - horned
one set PP - hermaphrodite, polled

The horned hermaphrodite goat can be explained in fact with freemartinism, as freemartinism is a slightly different process than the PP-hermaphrodite. I did some research on freemartinism some time back in regard to cows and found that in sheep and goats the same defect can occur but much rarer:

in cow twins that are male and female, the female will most likely be a freemartin because her oestrogen production was blocked in utero be the testosteron production of her male twin which sets in earlier than the oestrogen production but will block the oestrogen receptors in the female (very loosely explained, I'm too tired right now to search for the correct English phrases).


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