Use of acid stable protease in animal feed

An animal feed composition comprising (a) at least one acid-stable subtilisin and (b) a vegetable protein or protein source, wherein the composition has a crude protein content of 50-800 g/kg, wherein the acid stability of the subtilisin means that the activity of the subtilisin in purified form, in a dilution corresponding to A280=1.0, is at least 40% of the reference activity of the subtilisin, wherein the activity of the subtilisin is measured after two hours incubation at a temperature of 37° C. in a buffer of 100 mM succinic acid, 100 mM HEPES, 100 mM CHES, 100 mM CABS, 1 mM CaCl2, 150 M KCl, and 0.01% Triton X-100 (pH 3.5), and wherein the reference activity is measured after two hours incubation at a temperature of 5° C. in the same buffer but adjusted to pH 9.0, wherein the activity and reference activity are measured after these incubations, at 25° C. in Suc AAPF pNA (pH 9.0).