author(s)
Muhammad Zubair, Mohsin Ali, Maqbool Ahmad, Sajid Mahmood Sajid, Ijaz Ahmad and Shafia Tehseen Gul

abstract
Livestock is a major sector nowadays converting into an industry. Buffalo is one of the major constituents of the animal sector and is liked mostly due to its milk and meat in the Asian countries. Use of artificial insemination technique has improved meat and milk quality in this animal. Artificial insemination is one of best and quick technique to improve reproductive efficiency. However, the major problem with this reproductive technique is a reduction in the quality of semen during freezing and thawing. The production of reactive oxygen species during the process of cryopreservation hampers the motility of spermatozoa. The reactive oxygen species decreases cellular viability by initiation of lipid per oxidation of bio-membranes. To minimize this damage, antioxidants are used as cryoprotectants against the lipid per oxidation of bio-membranes. There are many antioxidants used to counteract the problems occurring during cryopreservation. In this review the beneficial effects of Selenium and Vitamin E as antioxidants on cryopreservation of semen are considered to be monitored.