On what basis the sperm quantity of a man is enhanced?

Varies. Amount of semen ejected during ejaculation will vary widely between men and may contain between 0.1-10 milliliters (note that a teaspoon is 5 ml and a tablespoo is 15 ml). Adult semen volume is affected by the time that has passed since the previous ejaculation; larger semen volumes are seen with greater durations of abstinence. The duration of stimulation leading to ejaculation also affects vol.