Super-fetation in Strathmore

[Cattle Rack Rancher]

Cow decides two head better than one
this document web posted: Wednesday May 25, 2005 20050526p59

By Barbara Duckworth
Calgary bureau

STRATHMORE, Alta. - Randy Kralik thought he was finished calving three months ago and then he found a newborn wandering the barn yard in the first week of May.

The strange thing was that the calf was following a cow that already had a three-month-old youngster born in February.

He speculated the calf belonged to another cow and that this one had stolen the baby. A pregnancy check on the other cow revealed it was due to calve this summer.

The only explanation was that the nine-year-old Simmental had dropped a second calf, especially when he noticed it showed signs of having recently delivered.

"Maybe she is a cow who doesn't believe in stopping at one," Kralik said. "To me, this is a miracle."

While some veterinarians did not believe him, another suggested the cow must have come back into heat and was rebred while already pregnant.

Both calves were 90 pounds at birth but the oldest is now nearly 300 lb.

The threesome is wandering the pasture near Kralik's Strathmore area home. The cow tends to push away the older, bigger calf while letting the new one nurse. With plenty of new grass available, the older calf appears to be doing well.

This situation is known as super-fetation and occurs when a pregnant female is mated during pregnancy so that two or more embryos result from different ovulation cycles and conception times. It is often viewed with skepticism but is known to occur on rare occasions.

According to a 2002 dissertation written by University of Louisiana doctoral candidate Joel Carter, superfetation can be difficult to identify with certainty.

It is different from twinning, where two or more siblings result during a single ovulation.

It has been observed in many different livestock species as well as cats, rats and hares. It has been known to happen with natural breeding, artificial insemination and embryo transfer, when technicians thought a cow was returning to heat and was rebred.

 

[sidney411]

That's pretty amazing. I don't see how the 2nd fetus doesn't get expelled at the birth of the 1st calf though.

 

[Cattle Rack Rancher]

Hmmm: If you could do this with cows and get them to calve every three months, you could produce 4 calves a year per cow in a rotation so that you could have calves to market all year to take advantage of short term fluctuations in the market cycle. Sounds like a money maker to me. ;-)

 

[jt]

Hmmm: If you could do this with cows and get them to calve every three months, you could produce 4 calves a year per cow in a rotation so that you could have calves to market all year to take advantage of short term fluctuations in the market cycle. Sounds like a money maker to me. ;-)

that is an amazing story.

seems like the second calf would not enough colostrum :?: :roll:

jt

 

[jerry27150]

i too, had one like that in the late eighties from a hereford

 

[bward]

We had one calve 3 weeks later. I too find it amazing that the second baby survives the first labour and delivery. I also feel for the cow that has to go through that birthing process after she has has barely had time to recover from the first one.

 

[msscamp]

Assuming one didn't get confused by cows that had already calved, but then calved again - think of the possibilities! Could be an amazingly profitable thing with the proper nutrition and management! Hmmmmmm, I wonder if it may be hereditary?

 

[sidney411]

That is a good point, I didn't think about the colustrum aspect. How does the 2nd calf get any colustrum? If the 2nd calf is born 3 months after the 1st she should be bred back again from the 1st calving also. I think I will do a little digging around on this one. Interesting.

 

[Caustic Burno]

I smell Smoke.

 

[sidney411]

Although superfetation has been reported in cattle and other species, there is considerable skepticism as to its existence due to the lack of clear evidence in these reports. Other explanations such as embryonic diapause or differential growth of twins have been suggested as more accurate descriptions of the cases reported as superfetation. The hypothesis of this study is that if a viable pregnancy can ensure maternal recognition in cattle, an asynchronous embryo can develop in a more chronologically advanced uterine environment. The objective was to produce superfetation by (1) ovulation induction and artificial insemination (AI) of pregnant cows and (2) transfer of 7-day embryos to cows with more advanced pregnancies. An attempt to produce superfetation by induction of ovulation in mated cattle with human chorionic gonadotropin (hCG) followed by AI was unsuccessful. Ovulation was induced in pregnant cows on day 7 but could not be induced >23 days of pregnancy. Subsequently, it was shown that uterine stage bovine embryos (7-day) could develop when transferred to recipients on day 14 of pregnancy, but not on day 28, day 60, or day 90 of pregnancy. Twins (7 days asynchronous) were produced in a recipient that received two 7-day embryos 14-days post-estrus. Although the younger twin was a heifer and her co-twin was a bull, the heifer was not a freemartin. FSH and hCG treatment 7 days prior to embryo transfer (ET) did not increase the rate of superfetation in 14-day or 25-day mated recipients. The nonsurgical ET technique may have caused pregnancy loss in recipients receiving embryos >25 days post-estrus. Two sets of asynchronous twins were produced by transfer of 7-day embryos to 14-day pregnant recipients. An additional experiment was undertaken to determine if asynchronous embryos could develop following maternal recognition in pregnant cows yet prior to invasion of the contralateral uterine horn by the primary conceptus. Asynchronous twins were produced following transfer of 7-day embryos to a 13-day pregnant recipient but not in 19-day pregnant recipients. Asynchronous twin pregnancies (superfetation) were therefore consistently produced in this series of experiments by transfer of embryos to recipients up to 16 days of pregnancy.

http://etd02.lnx390.lsu.edu/docs/availa ... 02-222405/

 

[jerry27150]

according to the old vet i had it was a trait of some older herefords to drop one 3 months later. mine didn't even own new one. just kept going with the older calf. everything had freshened & extra calf just appeared & i thought maybe one of my heifers had dropped one, but they hadn't. & no one else had herefords in the area & it was definately a new born. so i asked the vet about it