A monogastric animal refers to an animal that has a single stomach chamber for digestion. Out of the given options, chicken is an example of a monogastric animal. Chickens, like humans, have a single stomach compartment called the gizzard.
The gizzard is responsible for breaking down food through mechanical digestion. It contains small stones or grit that the chicken swallows, which help grind and crush the food. Once the food is finely ground, it moves into the small intestine where it is further digested and nutrients are absorbed.
On the other hand, goats, cows, and sheep are not examples of monogastric animals. They all belong to a group of animals called ruminants. Ruminants have a four-chambered stomach that allows them to digest and extract nutrients from plant material that is difficult to break down, such as grass and hay. The four chambers of their stomach are the rumen, reticulum, omasum, and abomasum.
In summary, while goats, cows, and sheep are ruminants with a four-chambered stomach, chickens are monogastric animals with a single stomach chamber, known as the gizzard.