To what extent are the animals responsible for their life.

I'm unsure what you mean here. Are you asking about the animals on the farm being responsible for their own fate in the story?

In a nutshell, during old major's speech the animals are easily taken away by the enthusiasim of major's persuading words in which he mentions 'MAN' as their only enemy .The animal gain a revolting spirit without considering the reality of their life After the rebelion they advocated for the pigs enjoys all the priveledges in the farm. they does not realise that they are deceived by the pigs.they realy know the truth but fail to ague