author(s)
Debbarma Kinkar, Karunakaran M, Sarkar Debajyoti, Debbarma Asish, Rahman Mokidur and Swain K Sangram

abstract
Artificial insemination (AI) and semen cryopreservation are the most widely used assisted reproductive technologies (ART) in livestock farming. Bovine reproduction, particularly in developing countries, relies heavily on assisted reproduction using AI with cryopreserved semen. During cryopreservation, the sperm cells face plenty of cold-induced insults. Especially oxidative stress due to excessive Reactive Oxygen Species (ROS) production, the sperm plasma membranes suffer a lot of damage. It leads to the reduction in the quality of spermatozoa in terms of its motility and fertility. Additives are various supplements added in semen extender to improve the freeze thaw sperm recovery and fertility. Majority of the supplements have antioxidant property hence scavenging free radicals and preventing lipid peroxidation. Semen additives are classified based on their chemical composition and their mechanism of action. This review article will discuss about various semen additives used over the past decade for cryopreservation of bovine semen.