Abstract The review of the biochemical composition of semen by Mann (1964) illustrates the sparsity of this type of data on avian semen. Recent increases in the use of artificial insemination, along with interest in semen dilution and preservation in turkeys, points out the need for more detailed examination of turkey semen. The purpose of the present study was to ascertain the elemental content of whole semen obtained during various times of the breeding season from two breeds of turkeys. It was also possible then to determine any changes that may occur due to length of time the toms were in semen production. Toms used in this study were hatched in late March and early April. At 12 weeks of age, they were placed on range and remained there until late fall. Semen collections began in late November and were carried on for a period of six months. At each collection . . .