So, if you going to make undead with simple Animate Dead (or Fell Animate), Su abilities will be lost:Even Awaken Undead wouldn't restore them:Special Attacks
... retains none of the base creature’s special attacks.
... loses most special qualities of the base creature. It retains any extraordinary special qualities that improve its melee or ranged attacks.To keep (Su) abilities, you will need to use more advanced spells, such as Create Undead/Create Greater Undead. Undead with "Bone Creature" or "Corpse Creature" template retain all their SA/SQUndead also regain any extraordinary racial abilities they had in life, such as poison or scent.