The problem with taming out aggressive behavior in sheep and pigs has been patched.  Current game mechanics do not currently work for taming out seeking and melee ai tasks. This may be fixed in version 1.16.

The 2.2.0 release does have fleeing ai for sheep and wild pigs enabled. This behavior can be tamed out at gen one.

I did make pigs a bit testy and likely to take a bite out of you if you stay too close to them for long, but they will not seek you unless you provoke them.  This behavior in pigs might tame out at very high generations. I'm not sure and did not test for that. The intent is that you always need to have care around pigs, period.

Both sheep and pigs will seek you if you have attacked them, but only if you are in very close proximity to them while they are in an aggressive state.

Fixed an issue with version 2.0 that allowed pigs to seek the player but only allowed them to attack when in emotion state "aggressiveondamage".