Chicken dying in one tick from fire damage.

If you build a quick tick lava dispenser to light a chicken on fire, the chicken dies in one tick and doesn't leave any drops.

built the system in 16w02a and it didn't work, down graded the world to 15w51b and it worked as intended... haven't tried any other animals at this time....

I have included pictures of my redstone...
Lava bucket in top dispenser.