Baby domectic animals never drop their equipment

/summon Sheep ~ ~ ~ {Equipment:[{id:stone,Count:64b}],DropChances:[1f]}

This sheep will drop stones when it is killed by a player.

/summon Sheep ~ ~ ~ {Equipment:[{id:stone,Count:64b}],DropChance:[1f],Age:-10000}

This sheep won't drop stones when it is killed by a player.