wow, thats kinda cool how they don't kill the cow for meat like we do.
Cow Blood
The traditional diet of the Masai (also spelled
Maasai) people in Kenya and Tanzania is derived mostly from their
cattle, though they do not often eat beef; rather, they eat milk and
blood which is harvested by puncturing the loose flesh on the cow's
neck with an arrow. The wound is closed after a gourdfull of blood is
obtained. This operation can be repeated every month or so with no harm
to the cow. The Masai typically drink blood mixed with milk.

Cow
blood is also consumed by other rural people, usually to avoid wasting
it when a cow is butchered. (Europeans also use blood in 
black pudding, 
boudin noir and 
blutwurst.)
Cow blood can be cooked with fresh or sour milk as follows: Pour the
fresh blood through a sieve to separate it from the clots. Mix three
parts liquid blood to one part milk (or equal parts blood and sour
milk). Cook over low heat, stirring often, for twenty to thirty
minutes. The mixture should thicken like scrambled eggs. If desired,
butter, fried chopped onions, or salt can be added during cooking.
Serve with Ugali, Fufu, or boiled Plantains, or Rice.