Revisió de la tècnica de criopreservació espermàtica i estudi de la seva optimització en biotecnologia de la reproducció porcina

Abstract

Sperm cryopreservation is a technique integrated in the animal reproductive biotechnology that allows the preservation of male gametes at low temperatures, particularly at -196ºC, for long periods of time in order to maintain their fertilizing capacity. The technique is used in different animal species for various purposes, including the reproductive, the preservation of genetic material, the easier international trade, etc. The work methodology has consisted of a literature review conducted in several databases by entering keywords to search for different publications such as theses, scientific articles, review articles, all related to sperm cryopreservation. In this work has been used as a model the boar sperm, which presents a greater susceptibility to cryopreservation due to the high content of polyunsaturated fatty acids and the low cholesterol presence in its membrane. From 2006 until today, the use of boar semen cryopreserved for the practice of artificial insemination (AI) represents only 1% of the inseminations carried out, this is due to the fertility rate and litter size using frozen semen is much lower than that obtained when using fresh cooled semen; with a 20-30% of difference in the fertility rate and 2-3 piglets less per litter. In recent years, several studies have been conducted to optimize the protocol for cryopreservation of semen of this species in order to improve sperm survival and the fertilizing capacity of sperm thawed. In this work has been reviewed some of the improvements to the cryopreservation protocol tested until now as: modifications of the technique itself and adding cholesterol, antioxidants or seminal plasma in freezing extenders. Despite the improvements achieved over the years, it is necessary to continue testing with new substances and different concentrations of the substances studied so far, in order to optimize and monetize the technique of cryopreservation of boar sperm to be of interest within in the sector