For the health and productivity of your birds, it is important that they be fed diets that meet their nutritional requirements. Complete feeds can be purchased that are formulated to meet all the nutritional requirements (energy, protein and amino acids, fat, vitamins, macro- and micro-minerals, etc.) of a particular class of poultry. If mixing your own feed these nutritional requirements must be taken into account.
Poultry diets are composed of a variety of different feed ingredients mixed in the proportions needed to provide the bird's needs for energy, protein, minerals, and vitamins. No single ingredient will meet the nutrient requirements of a flock so a mixture is required.
The dietary requirements vary among the different poultry species. The requirements are most often expressed in terms of a dietary concentration. The percent of a nutrient in the diet is dependent on the level of energy in the diet. Diets that are high in energy while need higher concentrations of the different nutrients (referred to as nutrient-dense diets) because the birds will eat less of a high energy diet and they need to be able to obtain the total amount of each nutrient required daily. Diets that are low in energy while needing lower concentrations of the different nutrients because the birds will eat more of the diet and thus get the total amount of the nutrients they need each day.
It is important to feed the right feed to your flock. The nutrient requirements will differ depending on the species, level of productivity, and the age of the birds being fed.
Feed passage in broilers - A complex problem (University of Florida)