Major contribution to the semen is from:
Semen which is ejaculated during male sexual act is composed of fluid and sperm. vasdeferens-10% seminal vesicles-60%-mucoid consistency prostate gland-30%-milky so the bulk of semen is from seminal vesicles. TEXTBOOK OF MEDICAL PHYSIOLOGY ,GUYTON,Pg no:888,8th edition
Testes
Seminal vesicles
Prostate
Bulbourethral and urethral glands
Infertility