# Does having a twin sister affect a goat bucks fertility?



## Saanens N Alpines (Oct 20, 2010)

I had someone tell me this today and had never heard anything like this. They said if a male goat has a twin sister he has a 50% chance of being sterile or unable to breed. They also said that with Boer goat bucks, they couldn't be registered until proven. Not sure if it was only if they had a twin sister or what....lol! I asked another former Boer breeder and she said she had never heard this either.


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## Kfin (Jun 23, 2010)

I sure hope not, I just bought a buck that had a twin sister. :?


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## keren (Oct 26, 2008)

The person that said that was very confused ... They were thinking COWS not goats and they got it backwards. In cows, a mixed sex pair of twins, the FEMALE will be infertile about ninety seven percent of the time, but the male has no fertility problems. This is called freemartin and happens in cows but not really in goats. Do a search, i'm sure i've explained the mechanism before. I'd tell you again now but i'm on my cell phone


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## keren (Oct 26, 2008)

Oh with the registration thing, being in a different country I can't really help, but our boer registry doesn't require that the bucks are proven - that would be silly - you couldn't sell a registered buck or show a buck until he was mature!


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## nancy d (Oct 5, 2007)

All registries will take your money no questions asked. :wink: 
And it's true, the person had goats crosswired with cows.


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## liz (Oct 5, 2007)

Better tell my bucks that they couldn't have sired the kids they did because both had twin sisters :wink: 

Fertility is an issue with male/female twins in cattle....not in goats.


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## KW Farms (Jun 21, 2008)

Yep...cows...not goats.


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## Epona142 (May 26, 2008)

On the other hand, there are cases of freemartin goats. Does that have male siblings and are sterile.

I believe my friend's doe, who had three or four male littermates, is a freemartin.


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## logansmommy7 (Nov 11, 2009)

Yep-I've heard about it in cows first hand...one of our black angus cows had twins a male and female and had this problem. Haven't heard about it in goats tho...think it might have been a mistaken thought!


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## myfainters (Oct 30, 2009)

Epona142 said:


> On the other hand, there are cases of freemartin goats. Does that have male siblings and are sterile.
> 
> I believe my friend's doe, who had three or four male littermates, is a freemartin.


This could only happen if they share the same sack (not the same horn) 
More than likely the sterility was a genetic issue and not caused from her male siblings hormones. onder:


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## Epona142 (May 26, 2008)

I've been doing some researching on it because this doe stayed at my place for a while. 

She is polled, but not from polled x polled. No glaring visual cues but has very tiny teats and and apparently immature vulva. No protrusions though. 

None of her sire's other progeny appear to have issues (popular sire) but no idea on the dam. 

She was 'bred' twice before my friend bought her, didn't settle. Came to my house on two seperate occasions to be bred and both times, never came into a heat. I've never missed a heat before, but I imagine it's possible. I kept her housed with the buck 24/7 the second time. Never saw evidence of being bred.

I think she's a freemartin personally. Which sucks, cause she's a NICE goat. And my friend's favorite.


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## firelight27 (Apr 25, 2009)

That would be awful in goats since having twins, triplets or more is completely normal. You would have so many sterile goats! I never knew that about cows though. Bizzaro.... I guess that is why you don't want twins in cattle. You don't want twins in horses because they will abort the pregnancy in most cases (I don't remember the percentage, but it is very high.) It has something to do with the mare's uterus not having enough surface area to support multiple foals. If the babies carry to term, one can be mummified, or born dead, or both can be born dead. At the least, if one or both are born alive, they are very tiny and weak, often premature, and survival rates are horrid (for the mare too.) That is why ultrasounds at about two weeks after breeding is exceptionally important in horses. You can pinch a twin at that point.


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## Saanens N Alpines (Oct 20, 2010)

Thanks for all your input. I couldn't imagine how I had never heard of this before, if it was true!


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