To level up Taming Knowledge:

• Craft rope arrows
• Craft taming items
• Tame creatures

Rank1 (Level Requirement 6):

• Wood Taming Trough
• Fur

Rank2 (Level Requirement 9):

• Feeding Trough

Rank3 (Level Requirement 15):

• Summoning Pool
• Small Soul Suppress Stone

Rank4 (Level Requirement 24):

• Herbivore Feed
• Carnivore Feed

Rank5 (Level Requirement 30):

• Summoning Stone

Rank6 (Level Requirement 36):

• Soul suppress Stone