Using Exogenous Enzymes to Increase the Nutritional Value of Soybean Meal in Poultry Diet

Abstract

Soybean meal is by far the most widely used protein source in animal feed all over the world. It is estimated that about 63% of all protein sources used in animal feed is from soybean meal while 98 % of the plant protein used in poultry feeds is from soybean meal in the U.S. (Soybean meal INFO center, 2010). The major reasons for the popularity of soybean meal in poultry and swine feed include: 1) compared with other plant protein sources, soybean meal is not only rich in protein (44 48%), but also can provide a complete protein with almost all essential amino acids for animals (Table 1); 2) the development of heating process to denature the anti-nutritional factors, especially trypsin inhibitors in soybean; 3) the discovery and production of vitamins by using chemical synthesis and fermentation. Six decades ago, animal protein was an essential ingredient in animal feed for providing not only protein, but also minerals and vitamins, especially vitamin B12; 4) further reduction of animal protein in the feed due to the concern of the health and safety of animal byproducts and the concern of phosphorus load in animal waste; 5) modern poultry and swine producing system restricted the use of other plant protein source, such as milling byproducts in animal feed; 6) computer based least-cost feed formulation program proved that the corn and soybean meal based simple diet fortified with vitamins, minerals and methionine is the least cost in producing broiler chicks and turkeys in the U.S. The simplicity of the diet can also reduce the cost and time associated with purchasing, storing and handling more ingredients.