Humans have eight different blood types. How many and what blood types do cows have?

Answer 1

Humans have far more that 8 blood types. You're referring to the 8 blood types of the ABO blood group system in humans. This is the most important blood group system in humans (because of it's impact on transfusions), but it is only one of 29 blood group systems in humans. Each blood group system is a group of related blood types that characterize antigens on the surface of blood (and other) cells controlled by a single locus (gene or group of related genes). So humans have 29 blood group systems, with a number of blood types in each system (never actually counted them up). Bovines (cattle) have 11 blood group systems and I counted 68 different antigens (blood types) in total.

Answer 2

For the same reason that they have different skin colours, hair & eye colours etc - mutation has caused genetic variation. There are many different blood groups, of which the most (?) important are A, B, O. These are due to antigens on the red blood cells. There are three forms of these antigens - A,B, and O. People either have A, B, O or both A & B - giving the groups A, B, O and AB. The different antigens are produced by a gene now called "I" which exists in three forms (alleles). If you give a patient the wrong blood group, the blood cells will clump together (agglutinate) - and clumps of blood cells in the blood vessels won't do the patient any good at all! For a planned transfusion, other blood groups will have to be considered, not just A,B,O.

Answer 3

There are four blood types and two Rhesus factors for a total of 8 blood groups.

Cows have: about 800.