Sperm count is a measure of the number of spermatozoa per ejaculation or per measured amount of semen. It is used as an indication of a man's fertility. Casual sex with a new partner once in a while can ramp up the sperm count, revealed an interesting study. The researchers also suggested that men produced higher quality ejaculates when exposed to novel, rather than familiar women. The team from the College of Wooster in Ohio also found that men ejaculated more quickly when viewing a new woman after being exposed to the same woman repeatedly.
For the study, the research team asked 21 men to provide semen samples while watching seven different explicit three-minute clips of a male and female having sex. The study participants used the same private room to produce the semen with 48 to 72-hour breaks between each session.
The first six clips used the same male and female actor while the seventh clip used the same male actor but involved a different female actor. Apart from the quality of sperm produced, the length of time it took to ejaculate was also recorded by the researchers. They found that the men produced healthier, higher volume sperm in a shorter amount of time when exposed to the seventh clip featuring a different looking female.
The researchers wrote, "An increase in the total number of motile sperm may result in higher likelihood of fertilization and greater ability to compete with other male's sperm. Whereas a decrease in the time to ejaculation may decrease the likelihood of an extra-pair copulation (with a partner that is not your own) being detected."
The study findings can help in fertility treatments since ejaculate samples used to test for infertility are often collected with the use of images depicting women other than the man's partner. The authors concluded that their findings are the first to demonstrate that men's ejaculate behavior and composition change in response to novel female stimulus.