If the doe is butting the kid only while trying to nurse and the kid is being bottle fed, I don't see the harm. Goats like that companionship, and the doe has done nothing wrong, except preventing the kid from nursing. And honestly, I think that this is one of those cases where separation and/or bottle feeding are not strictly necessary. I feel that the owner is rightly concerned, but that they may be overly concerned. I'm all for at least giving the doe a chance, personally...by separating she isn't even getting an opportunity. Tying the doe up is an excellent idea, also. This seeming mastitis or unwillingness to nurse all of a sudden are what concerns me the most, that is what needs to be attended to first.But if she is butting the kid when it tries to nurse it could be dangerous for it... you might need to tie the mother up at least. If we have a ewe that totally rejects a lamb we will sometimes separate them, even if she has milk. If there’s a chance of nursing, sometimes they just need tied up closely and observed/assisted nursing, but if she’s fully dry or has mastitis there’s not much point in confining her with the kid, and with a grafted lamb the bond is usually not as close...