Swine sperm freezing and its use in farms

Abstract

The majority of swine artificial inseminations (AI) performed in the world uses semen in the liquid state, diluted and refrigerated at 15-18ºC for 1 to 5 days, being 85% of them realized in the day of collection or in the next day. However, this storing temperature limits the transportation, as well as reduces the semen shelf-life. Therefore, the expansion of swine AI could be even better if other technologies for swine sperm preservation, as cryopreservation, were developed. The AI with frozen semen requires two to three times more sperm per doses, litter size is decreased in one to three piglets per parturition, and parturition rate is smaller than AI with refrigerated semen, which turns the procedure economically not viable for use when compared to the traditional technology. The lower fertility and prolificity of frozen swine semen are attributed to functional and structural alterations in the cell, especially in the plasma membrane, resulting from cold and osmotic shock to which the sperm is subjected during cooling, freezing, and thawing. This review aimed to highlight the factors involved in the process of swine semen freezing, as well as the possibility of use of this biotechnology in the farms, associated with different AI techniques.