This is a good question. The battle of Cowshed is an pivotal moment. As such, this battled had a few important effects.
As a group, the animals feel that they are now powerful enough to defeat any human attack. They are confident. They also want to remember this day. So, October 12th, the anniversary of the Battle of the Cowshed, is to be celebrated. This shows the collective effect.
On a more individual level, the two animals who are most honored are Boxer and Snowball.
Snowball who studied the battle plans of Caesar was a brilliant tactician. He allowed the animal to win. He also fought bravely and won the respect of the other animals.
Boxer also distinguished himself, but there is a difference. He hit a boy in the head and feared that the might have killed him. This shows that Boxer does not want to hurt anyone. He even laments:
"Who will not believe that I did not do this on purpose?"
This is in sharp contrast to Snowball or Napoleon, who have no pang of conscience in killing anyone.