When you summon any breedable passive mob with the NoAI NBT tag set to 1, you can still see heart particles from the mob when you give the correct breeding material.

What I expected to happen was...:
The AI-less passive mobs shouldn’t be able to detect any materials that are right-clicked on it.

What actually happened was...:
The AI-less passive mobs are able to detect breeding materials.

Steps to Reproduce:
1. Summon a breedable passive mob using /summon [insert mob’s Savegame ID here] ~ ~ ~

(for horses, it is /summon EntityHorse ~ ~ ~

2. Give the mob its correct breeding material to see heart particles.