Semen quality is a measure of the ability of semen to accomplish fertilization. The penis contains a tube through which semen (a fluid containing sperm) travels. Pre-ejaculate contains some chemicals associated with semen, such as acid phosphatase. Ejaculation is the expulsion of semen from the urethra. It is a passage both for urine and for the ejaculation of semen. The virus may also be present in semen and genital secretions. The urine will be examined for the presence of semen. It is partially responsible for the distinctive odors of urine and semen. Use of the drug may be confirmed by detecting its presence in semen or urine. The process that results in the discharge of semen is called ejaculation. There are multiple methods used to obtain the semen necessary for artificial insemination. Lyme spirochete DNA has been found in semen and breast milk. Hippocrates believed that the embryo was the product of male semen and a female factor. Different modes of condom failure result in different levels of semen exposure. Cows can also catch FMD from the semen of infected bulls.