Blood meal

Blood meal is a dry, inert powder made from blood, used as a high-nitrogen organic fertilizer and a high protein animal feed.

Blood meal can be used as a livestock dietary supplement and is mainly added to supply dietary lysine for cattle, fish and poultry.

[2] Blood meal, bone meal, and other animal by-products are permitted in certified organic production as soil amendments, though they cannot be fed to organic livestock.

[4] Blood meal can be spread on gardens to deter pest animals such as rabbits.

The theory is that the animals smell the blood and are repelled by the odor.