Out of the given options, the non-ruminant farm animal is rabbit. Non-ruminants are animals that do not possess a specialized stomach for fermentation of feed. Instead, they have a simple stomach. Rabbits belong to the category of non-ruminants as they have a simple stomach and are hindgut fermenters. In contrast, cattle, goats, and sheep are ruminant animals that possess a specialized stomach that aids in the fermentation of feed through the action of microorganisms.