Proteases
Much of the early work in the 1950s and 1960s involving proteases supplementation to cereal based diets did not result in improvements in bird performance. However, recently, supplementation of poultry diets with enzyme mixtures, including proteases and amylases, have produced significant improvements in growth performance. More recently, researchers were able to estimate the value such enzymes play in sparing protein sources both in vivo and in vitro .