Chickens have only 350 to 500 taste buds, while we have 3,000 to 10,000 of them. They dislike strong flavors rather than having strong preferences. Their food choice may be more based on the visual and tactile cues from the food rather than the taste.
The sense of smell, like taste is not as critical to birds as it is to mammals. However one important odor that chickens can detect before we do is ammonia, and it is critical to their health. Ammonia is a gas released by bacteria that decompose manure. It is caustic, causing skin lesions, eye inflammation, respiratory problems and other issues.