Crude fiber is an indispensable nutrient in chicken diet, which can fill crops and gastrointestinal tract, stimulate gastrointestinal peristalsis, help digestion, stimulate appetite and promote metabolism. If the crude fiber content in the diet is too low, it will cause digestive tract diseases, feather growth and development, pecking addiction and so on. However, the high content of crude fiber in the diet is not conducive to the growth and laying of chickens. The ability of chicken to digest crude fiber is much worse than that of domestic animals. Cellulose constitutes the cell wall of plants, and the cell wall is not destroyed, so the contents (nutrients) of cells cannot be digested by contacting digestive enzymes. If there is too much crude fiber in the chicken diet, the volume of the diet is enough, but other nutrients are relatively reduced. Moreover, due to the influence of excessive crude fiber, the digestibility of various nutrients decreases, resulting in insufficient nutrients and energy, which leads to poor growth and development of chickens, emaciation of chickens and decline in egg production rate. The content of crude fiber in wheat bran feed is relatively high (wheat bran 12.6%, whole bran 2 1.7%). The content of crude fiber in hay powder depends on the quality of grass, which is generally 23% ~ 36%. The content of crude fiber in seed feed is less (2% ~ 9%).

In chicken diet, the crude fiber content should not exceed 5%, and the general standards are: 2.5% ~ 3.0% for chicks and broilers, 4% ~ 5% for adults, and 3.0% ~ 4.5% for laying hens and breeders.