Item spawning please help

Ive been doing

ItemStack piggy = new ItemStack(AdvancedMiningDrillTraits.filledPigAnimalCage);

public boolean itemInteractionForEntity(ItemStack itemstack, EntityLiving entity)

    {

if (entity instanceof EntityLiving){

if (entity instanceof EntityPig){

        if(entity.worldObj.isRemote){

entity.isDead = true;

--itemstack.stackSize;

    EntityItem pig = new EntityItem(entity.worldObj, entity.posX, entity.posY, entity.posZ, piggy);

    entity.worldObj.spawnEntityInWorld(pig);

        }}

but it will only spawn one item the first time, then it just wont spawn the item

please help