I'm going out on a limb here and will assume that there is some relation to the Caw family? If this is the case, I'm certain that M.M. would be happy to oblige by donating for the good of the family. You would have to clear it through Fields first, but from what I understand she just lays around waiting to be plowed anyway; she should be easy to convince.
M.M. would be a good match, he also has very little body fat; he does a LOT of plowing. From what he has told me, he is a regular sperm donor and has actually won several awards for his efforts; I believe they called one a Slammy.
He's not so pretty to look at, so you'll want to go through a Dr. or do it "Discovery Channel" style so you don't lose your lunch.
If you're interested in finding out if he's in your family tree, let me know and I'll send him a letter with the request.