Then you should be able to find good sources of venison locally - I envy you. However I found it strange when I was touring the States - there seemed to be an abundance of deer as you say, but never could I buy any in a shop, be it a huge upper-class supermarket or a local butcher shop. Who gets to eat it all?

I adore eating venison, but it is terribly expensive here if you don't know any hunters personally!
About the oxtail and other RMB: of course it's fine if the dog can deal with it, but all dogs are not the same. I know quite a lot of people who are partially feeding raw, both personally or from a large forum, so I was just generally speaking. For a dog used to kibble, feeding very soft bones only at the beginning works usually best. Of course there are individuals who can deal with really hard bones from the start, but quite a lot of them will react the way angell has described. So, if one already knows there might be trouble, one should start the dogs on softer bones as chicken wings, necks and carcasses or calf or lamb breast, depending on what is available. Time enough to introduce harder bones later on.
What kibble lacks is mainly high value meat, not minerals, so it makes sense to feed meats without bones too if you can get it. It is a fact that meat alone is easier on the stomach of a sensitive dog than bones, so it can serve to get a delicate stomach used to digest raw stuff.
Judging from people seeking advice on forums, the combination of kibble and too many bones can lead to trouble frequently. A good kibble will give rather firm stools, bones will firm them up further, and so it can lead to constipation. Dogs fed on commercial dog food only will often show adverse reaction to the occasional bone - I've had one such, and another who had no trouble at all, so I think one should always be guided by the individual dog and not on iron principles.
Anyway, angell, don't give up on fresh food, but take it gently if your dogs are of the sensitive kind.
PS: I bought some oxtail on special offer once (it's very expensive here) and on her first piece of it was the only time Rhian has vomited bone so far, even though she had been used to chicken necks and calf bones. There was no trouble with the other two pieces later , but I made sure they were not going onto a completely empty stomach!