A good example of the "appeal to prejudice" propaganda technique is the tactic taken by the pigs to ensure that they are better-fed than the other animals. When it is discovered that the pigs are taking milk and the windfall apples instead of sharing them to the common pot, Squealer the pig makes an impassioned plea that the pigs need better food to stay healthy and smart, and thus run the farm. If they are not fed well, the farm will collapse and Jones will return.
Now if there was one thing that the animals were completely certain of, it was that they did not want Jones back. When it was put to them in this light, they had no more to say. The importance of keeping the pigs in good health was all too obvious.
(Orwell, Animal Farm, george-orwell.org)
By appealing to the prejudice ingrained in the animals by Old Major and the pigs, Squealer is able to convince them that this unfair distribution of food is actually in their best interests. Without the specter of Jones's possible return, the animals would understand that the equal society of Old Major's philosophy would have no unequal sharing of food.