"Nutritional needs" refers to the need for energy, protein and other nutrients in the daily life and production of animals. Nutritional needs are the average of a population, excluding all insurance factors that may increase the need. According to different purposes, the nutritional needs of animals can be divided into maintenance needs (energy and other nutrients for animal life maintenance) and production needs (such as growth, reproduction, laying eggs, etc.). Feed cost accounts for the main part of poultry production cost and is the main means to control production efficiency. Therefore, feed enzymes play an important role in poultry nutrition.
1 energy recharge
Poultry is the growth tissue, laying eggs, essential activities and energy needed to maintain normal body temperature from carbohydrates, fats and proteins in the diet. The main part of poultry's food intake is to provide energy. The dietary energy consumed by poultry can be used in three aspects: doing work, transforming into heat or storing in animal body in the form of body tissue (fat). Feed enzymes in poultry nutrition
are obtained when the energy contained in the diet is precisely proportional to other nutrients required for optimal growth, egg production or broiler body condition.
2 Protein and amino acid requirements
Tissue proliferation and regeneration of poultry for life and growth require continuous access to nutrients from feed. Therefore, the conversion of feed protein into body protein by feed enzymes in poultry nutrition
is an important nutritional process. Although the nitrogen content of various proteins is not exactly the same, but the difference is not significant. Generally, the nitrogen content of feed is multiplied by 6.25 to obtain the crude protein content. The nutrition of poultry protein is actually the nutrition of amino acids. More precisely, it should be the nutrition of essential amino acids, because the diet which can meet the requirement of essential amino acids can generally satisfy the amount of nitrogen needed for poultry to synthesize non-essential amino acids.