Artificial selection to obtain cows yielding high milk output represents
| 1. | Stabilising selection as it stabilizes this character in the population | 
| 2. | Directional as it pushes the mean of the character in one direction | 
| 3. | Disruptive as it spills the population into two, one yielding higher output and the other lower output | 
| 4. | Stabilizing followed by disruptive as it stabilizes the population of producing higher yielding cows |