There are several different choices for Animal By-Products to feed your lawn: 

Blood Meal - Containing 12-15% nitrogen nd about 3% phosphorus, this slaughterhouse waste can be worked into the soil when establishing a new lawn or activating a compost pile. Blood Meal is an expensive option. NOTE: Do not apply as a top dressing as it may burn the lawn. 

Bonemeal - When establishing seed, sod, sprig, or plugs, Bonemeal can be worked in to help establish roots. It contains roughly 22% phosphorus and 22% calcium. This is a more expensive option. 

Feather Meal - Showing up fairly often in natural fertilizers, Feather Meal contains 8-15% nitrogen. It is slow to breakdown so the nitrogen release is extremely slow, which is not suitable for all lawns. 

Fish Products - In the early 1990s, fish waste was scooped up by compost and fertilizer manufacturers as quickly as it was produced. Commonly called Fish Emulsion, it contains as much as 10% nitrogen and 6% phosphorus.