Chicken in its raw state weighs about 80% more than it does once it is cooked and processed into a dry pellet. Once it is processed you are left with only 20% of the actual meat.

The word "meal" in an ingredient is something that was weighed after the water was taken out. For example "chicken meal" is chicken which is weighed after it has been cooked and the water has already been taken out, giving you more meat and protein per weight volume.