Chubby heifer

Inger · Post by **Inger** » Sat Apr 19, 2008 11:21 am

They're looking lovely. The little black heifer may always be smaller than her sister. Time will tell.

Margaret, in answer to your question from the first page of this thread, yes the twin heifer was a freemartin. Her brother was fertile though. My Sister-in-Law used him for a few years to provide freezer calves.

wagra dexters · Post by **wagra dexters** » Sun Apr 20, 2008 10:19 am

Very interesting phenomenon, and very disappointing. I wonder why it happens in some species and not in others. It doesn't seem to have any specific rules. Horses and cows get it, the horse a non-ruminant, but goats & sheep don't. Strange! If anyone has the scientific explanation as to why some species and not others, I am very keen to learn about that.
Margaret

Duncan MacIntyre · Post by **Duncan MacIntyre** » Sun Apr 20, 2008 11:03 am

As far as I know freemartins only occur in cattle. It happens because there is overlap of the placental circulation allowing male hormones from the male calf to mix with the female calf's circulation and prevent the full developement of the tubular parts of the genital organs. Probably about one in twenty female calves twin to bulls will be fertile because this has not happened.

As far as I know it does not happen in horses, but they have their own troubles with twins since 90% of horse twins do not go to full term and abort. Of the few that are born most are weak and need a lot of nursing.

So in both species the tendency to produce twins is not a good trait to have - twin bulls are not a good choice to breed from since they may well pass on the tendency to twinning in their offspring.

Duncan

mindenho · Post by **mindenho** » Sun Apr 20, 2008 10:24 pm

Twins still doing very well but the size differential gets larger - definitely a short and a non-short I think. Will try and get some more photos but it is difficult in the barn - oh for some warmer weather and the grass gorwing so I can get them turned out. Duncan - will they be OK to breed from?

Duncan MacIntyre · Post by **Duncan MacIntyre** » Sun Apr 20, 2008 10:52 pm

Twin heifers should breed ok, but remember that they will possibly pass on the tendency to produce twins, which is not really a good idea.

We had twin heifers a long time ago, one long and one short. The short was sold at Stoneleigh, no registered progeny. The long one was a bit slow to get in calf, and I thought she was going to be pushing the upper end of breed standard size, so we ate her.

Duncan

wagra dexters · Post by **wagra dexters** » Mon Apr 21, 2008 6:53 am

All these years I thought horses could have freemartins because an old horseman told me so when I was a kid. That will teach me to do my own research in future.
Thank you, Duncan, for your prompt reply.
Margaret.