In order to ensure healthy and normal growth and development, chickens must constantly ingest food (feed) from the outside world and absorb various nutrients from these foods, including water, protein, carbohydrates, fats, minerals and vitamins. After these nutrients enter the digestive tract, most of them are digested and absorbed, and some of them cannot be digested, absorbed and utilized, and become feces and urine. Through feed analysis, we know that the nutrients contained in chicken feed can be shown in Figure 3-2.

Figure 3-2 Nutritional components in feed