Removal of the testicles prevents production of sperm and the male dog or cat will no longer be able to father puppies or kittens. (windsorhumane.org)
Other research suggests that eating more fruits and vegetables yields better production of sperm than meats and fats, said Schlegel, who is chair of urology at Weill Cornell Medicine in New York City. (health.com)
He determined that one component of the sex - determination system, a protein called MAP kinase, proved to be the link between the fatty acid monitoring and the switch from production of sperm to eggs. (sciencedaily.com)