I clip their collar to the fence, making sure the head is as high as it can go under tension so they can't lower it. Obviously a milk stand would hold them by the head, so much safer with respect to horns. But they can still kick out/up/back/fwd... all around and some choose to lay down... You may have to tie down the rear legs by the hocks to the milk stand as well, at least initially, until she figures out that you're not trying to kill her and that you're not going to give up/give in/stop.