The Amino Acid Composition of Rovine Semen*

Very few data are available concerning the amino acid content of mammalian sperm. The early work by Kossel (1) on the protamines of fish sperm and on the histones was primarily concerned with an attempt to elucidate the structure of the basic proteins. The basic proteins are, in general, characterized by a high arginine content. Zittle and O’Dell (2) have determined the methionine content of whole bovine spermatozoa and found an average value of 1.92 per cent (moistureand fat-free basis). Since the literature is obviously incomplete with respect to the amino acid content of sperm and since some of the problems of infertility might conceivably be related to one or more of the chemical constituents of semen, it seemed advisable to initiate a study of the amino acid composition of bovine semen.