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twin goats, both girls = one infertile?
- Thread starter klf73
- Start date
- Mar 19, 2009
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He is mistaken. However, I have heard of two cases of triplets (goats) where there were two boys and one girl. Both girls in those cases were infertile.
- Jan 31, 2009
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In case anyone is interested in the science behind why cattle get freemartins but goats dont ...
early on when the pregnancy is establishing, the first thing to develop is the membranes which form the foetus' half of the placenta. These membranes spread out and they have to cover a certain % of the uterus for the body to recognise the pregnancy and sustain it.
In monoctus animals (those which generally ovulate only a single egg eg. cattle, deer, alpaca, horse), the membranes spread out as described above. If for some reason, there is twins or triplets in a monoctus animal, the membranes generally overlap. Monoctus foetuses do not have the ability to move very much, so the membranes remain overlapped. If the twins are a mixed sex pair (ie bull and heifer) some of the hormones from the bull foetus are transported to the heifer foetus via the overlapped membranes, and it is these hormones that result in the female being sterile. There is no effect on the bull.
In polyoctus animals (those which generally ovulate more than one egg eg. pig, goat, sheep, dog, cat), the membranes spread out like mentioned, but in the case of an overlap of membranes, polyoctus foetuses are capable of motility in the uterus, so they simply move around and spread out until their membranes arent overlapping. Thus avoiding the transfer of hormones and avoiding the freemartin sterility issue.
Understanding that logic, of course there is the possibility that mixed sex bovine twins will not result in a freemartin, and multiples in goats can result in a freemartin. But I havent yet seen a goat or sheep freemartin.
Goattalker - I've had triplets, quads and quints in all sorts of sex combinations - including the one you mentioned - and have never had a sterility problem.
early on when the pregnancy is establishing, the first thing to develop is the membranes which form the foetus' half of the placenta. These membranes spread out and they have to cover a certain % of the uterus for the body to recognise the pregnancy and sustain it.
In monoctus animals (those which generally ovulate only a single egg eg. cattle, deer, alpaca, horse), the membranes spread out as described above. If for some reason, there is twins or triplets in a monoctus animal, the membranes generally overlap. Monoctus foetuses do not have the ability to move very much, so the membranes remain overlapped. If the twins are a mixed sex pair (ie bull and heifer) some of the hormones from the bull foetus are transported to the heifer foetus via the overlapped membranes, and it is these hormones that result in the female being sterile. There is no effect on the bull.
In polyoctus animals (those which generally ovulate more than one egg eg. pig, goat, sheep, dog, cat), the membranes spread out like mentioned, but in the case of an overlap of membranes, polyoctus foetuses are capable of motility in the uterus, so they simply move around and spread out until their membranes arent overlapping. Thus avoiding the transfer of hormones and avoiding the freemartin sterility issue.
Understanding that logic, of course there is the possibility that mixed sex bovine twins will not result in a freemartin, and multiples in goats can result in a freemartin. But I havent yet seen a goat or sheep freemartin.
Goattalker - I've had triplets, quads and quints in all sorts of sex combinations - including the one you mentioned - and have never had a sterility problem.
- Mar 20, 2008
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Username, Thanks for the good information! I knew about freemartins, but didn't fully understand it.
I learn a lot on this forum.
I learn a lot on this forum.
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We've found this to be true with our cattle pretty much 100% of the time. I don't think it applies to goats tho.
We've found this to be true with our cattle pretty much 100% of the time. I don't think it applies to goats tho.
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That takes me back to SNL's Pat skits!
Nope not true. Someone tried to tell me that and the resulting twins had quads of their own.
- Mar 19, 2009
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Yep, I have had normal triplets (2 bucks and a doe) too. I always wondered if the farms that were reporting the problem has something else going on.
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