Referring to an isolated polypeptide that has activity of LysozymeSelected from the group consisting of: (a) a polypeptide that has at least 80% at least 100% Sequence identity with respect to sec.id 20 227 amino acids.Nro: 4 or 1 208 amino acids of sec. Id.Nro: 8 (b) a polypeptide encoded by a Gene that has at least 80% at least 100% Sequence identity with respect to the coding sequence of the mature PolypeptideSEC. ID number: 3 or the coding sequence of the mature polypeptide of sec. ID number: 7 (c) a polypeptide encoded by a Gene that hybridizes with the complement of sec. Id.Nro: 3 or 7 in mid - to high stringency conditions, where the conditions of High stringency means for Probes of at least 100 nucleotides in length.The pre Hydration and hybridization to 5x SSPE in Forty Second C, 0.3% SDS, 200 micrograms \/ ml of crumbled Salmon Sperm DNA and denatured, and 50% formamide, following conventional procedures of Southern Blotting for 12 to 24 hours,And washing Three Times, each time for 15 minutes, using 2x SSC, 0.2% SDS, at 60 C.It also relates to a Composition of Animal Feed comprising the polypeptide, Nucleic Acid constructs.Vectors and host cells comprising the polynucleotides and Methods for their production.Referido a un polipeptido aislado que tiene actividad de lisozima, seleccionado del grupo que consiste en: (a) un polipeptido que tiene por lo menos 80% a por lo menos 100% de identidad de secuencia con respecto a los aminoacidos 20 a 227 de SEC.ID. NRO: 4 o a los aminoacidos 1 a 208 de SEC. ID. NRO: 8 (b) un polipeptido codificado por un polinucleotido que tiene por lo menos 80% a por lo menos 100% de identidad de secuencia con respecto a la secuencia codificadora del polipeptido maduro de SEC. ID. NRO: 3 o a la secuencia codificadora del polipeptido maduro de SEC. ID. NRO: 7 (c) un polipeptido codificado por un polinucleotido que hibrida con el complemento de SEC. ID. NRO: 3 o 7 en condiciones de rigurosidad media-alta, donde las condiciones de rigur
