Transova in madisonville. there is also another place in Madisonille can not remeber name but the number is 936-348-0379. Transova used to run $1800 but would buy the cow back after weaning. the other place is $1200 ($400 at preg check, $400 at birth, $400 at weaning).
I know there are a couple of places in Iowa and Illinois that you send embryos to and the put them in. Buy the calf at weaning. You can probably find somtin closer tho.
Yeah...there are people who do that. For the guy running the recips, it guarantees a premium on the calf weaned by each of his commercial cows. And yes...the deal should be agreed upon before the embryos are ever implanted.
I don't understand your question about a donor cow...this would be an option for somebody who has embryos on hand and no recips to put them in. It's an alternative to investing in a bunch of cows and then having your money tied up in recips that don't get pregnant with an embryo. You just pay for the calves at weaning usually, but there are different arrangements and terms.