Didn't know about the hormone thing FW, that's interesting. I once had a cat that pee'd on me (sprayed) when I was pregnant!!!
We started off with a Soay ram who definitely tried it on a few times. However I read somewhere that if you put a hand under their chin and tip their head upwards it stops them. Never touch them on the top of the head or the horns. Anyway we applied this tactic to him and any ram lambs born and it seemed to work. Now have a new ram who atm we can't get near but he will certainly get the chin up treatment once he feels bold enough to approach us.
Our sheep rarely get fed (except ewes pre and post lambing) as they do very well on grass and hay alone, but we do like to spend a bit of time with them to keep them tame and friendly, so made permanent "seats" of concrete blocks in each paddock where we spend a little time once or twice a week just talking to the flock and stroking them. All bar two will come for some fuss, and there is no food involved at all, they just seem to like being with us. One particular ewe will paw at my leg if I stop stroking as if to say, keep going keep going.