If clinical examination reveals gross congenital or acquired lesions then the diagnosis of infertility is simple. However, a complete BSE must usually be performed to pinpoint a problem. The normal values of BSE parameters for several species are listed in Table 1 . Clinical problems in our domestic animals can be grouped into a number of primary causes. Environmental effects might be the most common cause of reproductive problems in domestic animals.
Heat is probably the greatest offender, especially in stallions, bulls, and boars.
Rams are less affected because they are fall breeders. Excessively cold temperature can also limit a male's fertility, and freezing of testicular tissue results in sterility. Temperature-induced changes are diagnosed on history and BSE results. Therapy involves reversing the initial insult. Infectious agents are common problems, especially venereal diseases.