The primary function of the gastrointestinal system in animals is to digest food and absorb nutrients. This complex system processes various food types, breaking them down into smaller components through enzymes and acids. The system includes organs such as the stomach, intestines, liver, and pancreas, each playing a crucial role in digestion. Nutrient absorption mainly occurs in the intestines, where essential vitamins, minerals, and energy sources are taken up, supporting overall health, growth, and metabolic functions.