Fraternal/Identical twins

[alisonb]

One of my cows aborted last week. She would have been 4 months in calf, I found the fetus, development looked normal. She was on the cull list so I had her slaughted on Monday. She was carrying another calf, perfectly healthy/ normal. I feel like a murderer :shock: .
My question is - has anybody experienced something similar? I suppose this would have been seperate eggs and would have been fraternal twins?

 

[MO_cows]

Well that stinks! Sorry it happened.

Working with different registries over the years, I have seen it happen surprisingly often where DNA from a blood sample will show admixture, so the lab requests a hair sample. But the breeder swears that only one calf was born. So, the twin must have been aborted (undetected) or possibly re-absorbed if early enough in the pregnancy.

To tell whether fraternal or identical twins, DNA can tell the tale. If they are identical twins, from an egg that split, their DNA markers will be an exact match. If they are from 2 eggs, their DNA will not show an exact match. I don't think the origin of the twins has anything to do with whether or not they are both carried to full term.

 

[alisonb]

Thanks Mo. Can it be said that when an embryo splits into two seperate embryos the two identical twins will share the same placenta and amniotic sac whereas with fraternal twins these are seperate? In this case there were two seperate sacs and placentas.

 

[dun]

Thanks Mo. Can it be said that when an embryo splits into two seperate embryos the two identical twins will share the same placenta and amniotic sac whereas with fraternal twins these are seperate? In this case there were two seperate sacs and placentas.

No, there are normally 2 placentas. One of the old time beliefs was that if you had a bull and a heifer if there were 2 placentas that the heifer wouldn;t be a freemartin.
If the split happened sometime after implantation there would be (probably) 2 placentas and sacks. Had a long discussion with the vet a couple of years ago about this same subject. He explained it real well but couldn;t dumb it down enough for me to retain the particulars.
Just because you only see one afterbirth, unless you are right there from calf delivery through the passing of the AB you woudln;t know if there was one or two because of the possibility of the cow eating one (or both for that matter)

 

[Lucky_P]

I'm not saying it can't happen, and I had a client who swore up and down that their cow delivered two calves six weeks apart - I just have a difficult time, in my own mind, coming to terms with the possibility of a cow aborting or delivering one fetus, and not the other one - or at least, the likelihood of a second fetus surviving the opening of the cervix and uterine contractions without being delivered or subjected to placental disruption & the possibility of infection due to cervical dilatation.

Are you absolutely certain that THIS cow is the one that aborted?

 

[alisonb]

This is interesting
http://www.extension.org/faq/28606

Lucky_P - I am positive it was the same cow.

 

[hillsdown]

That is a really interesting article Alison.

 

[alisonb]

That is a really interesting article Alison.

HD I would certainly have dismissed it, one just never stops learning. The vet is coming over in the week so I will definitely run it passed him.