This invention relates to the use of the Aspergillus niger aspergilloglutamic peptidase in a feed composition containing cereals, pulses, oilseeds, and/or tubers to improve animal performance, reduce nitrogen excretion and/or reduce intestinal inflammation. Furthermore, the present invention relates to a feed composition or a feed additive comprising the Aspergillus niger aspergilloglutamic peptidase. The present invention relates to the discovery that the Aspergillus niger aspergilloglutamic peptidase is capable of efficiently hydrolyzing alpha-amylase/trypsin inhibitors that are present in wheat, barley and related cereal species, as well as hydrolyzing trypsin inhibitors that are present in pulses, oilseeds, and tubers. Furthermore, the present invention relates to a method of improving animal performance comprising improving feed conversion ratio, and/or improving daily weight gain, and/or reducing intestinal inflammation, and/or reducing nitrogen excretion in an animal fed a feed stuff containing alpha-amylase and/or trypsin inhibitors, comprising orally administering a sufficient amount of the Aspergillus niger aspergilloglutamic peptidase. It also relates to the pretreatment of feedstuff with the Aspergillus niger aspergilloglutamic peptidase.
