In Animal Farm, persuasion is used primarily by the pigs, most notably Squealer, for the purpose of maintaining total control over the other animals.
As a skilled public speaker, Squealer routinely uses his speeches to persuade the animals that the pigs are only acting in the best interests of everybody. This is shown clearly in chapter three when it is discovered that the pigs have taken the milk and apples for themselves instead of sharing them out equally. To justify this action, Squealer first claims that pigs need milk and applies because they are "brainworkers" and these foods have been scientifically proven to aid the brain. Secondly, he uses fear to stop the animals from voicing any complaints:
"Do you know what would happen if we pigs failed in our duty? Jones would come back! Yes, Jones would come back!"
Through a combination of false facts and fear, Squealer, speaking on behalf of Napoleon, successfully persuades the other animals to accept this unfair situation.