Cryopreservation of stallion semen: A Review

The cryopreservation of domestic animal sperms is a complicated process that necessitates the control of numerous factors in order to get the desired outcomes.Appropriate diluents and sperm dilution , cooling , and thawing rates are required to guarantee even a minimum success.To maximize the post-thaw recovery of sperm and, consequently, fertility, thorough knowledge of the intricate physiology of sperm for each species is also necessary.Cryopreserved semen is far less frequently utilized in equine artificial insemination (AI) than fresh or cooled-stored semen.This is caused, at least in part, by variations in the ability of different stallions' frozen-thawed semen to fertilize.Cryopreservation of semen is also connected with high prices.The breeding of animals has benefited greatly from the use of cryopreserved semen for artificial insemination during the past seven decades.Mammalian sperm were among the first cells to be effectively cryopreserved.The economic effectiveness of commercial artificial insemination using cryopreserved semen is therefore influenced by the number of insemination doses obtained per ejaculate, and also the one of the most challenging materials in the industry of equine semen is cryopreserving effectively without apoptosis or membrane damage.Stallions differ in their spermatozoa's cryotolerance; however, it is still unclear how much this variation is influenced by breed.Common cryopreservation methods for spermatozoa include direct submersion in liquid nitrogen and cryoprotectant-free vitrification.However, there is a chance that microbial contamination could occur with the direct freezing of sperm in commercial liquid nitrogen.So, cryopreservation aimed to protect and elongated the viability of sperms.Low-molecular-weight compounds that are very permeable are called cryoprotectants.By lowering the freezing temperature of the samples, spermatozoa are protected from freeze damage by ice crystallization.Glycerol, ethylene glycol, dimethyl sulfoxide (DMSO), and 1,2-propanediol are the four cryoprotectants that are most frequently utilaized.One of the most challenging materials in the industry of equine semen is to cryopreserve effectively without apoptosis or membrane damage.Therefore, this review explains in detail the steps of cryopreservation, its importance, and the types of cryoprotectants which added to stallion semen.