The Bug

The growth of sheep can be accelerated both by feeding them wheat and by them eating grass. However, only feeding wheat causes them to emit the green particles associated with growth acceleration, and them eating grass does not.

Steps to Reproduce

• Summon a large field of grass blocks below you.

  /fill ~7 ~-1 ~7 ~-7 ~-1 ~-7 minecraft:grass_block
  

• Summon a baby sheep and wait for it to eat some grass.

   /summon minecraft:sheep ~ ~ ~ {Age:-25000}
  

• As it eats some grass, take note as to whether or not green particles are produced.

Observed Behavior

Baby sheep do not produce green particles when eating grass despite their age being increased.

Expected Behavior

Baby sheep would produce green particles when eating grass as their "Age" NBT value is increased.