Influence of Semen Storage and Cryoprotectant on Post-thaw Viability and Fertility of Stallion Spermatozoa

Effects of glycerol concentration on the motility of equine spermatozoa after thawing

“…Investigated substances are specifically compounds of glycol: ethylene glycol, propylene glycol, diethylene glycol, dimethyl sulphoxide (Chenier et al 1998;Moore et al 2006;Hoffmann et al 2010) or various amides: formamide, methylformamide, dimethylformamide, acetamide or methylacetamide (Gomes et al 2002;Vidament et al 2002;Squires et al 2004;Alvarenga et al 2005;Ferreira et al 2008). Some of these alternative cryoprotectives are combined with glycerol and varying concentrations of each cryoprotective both individually and in combination have been described (Vidament et al 2002;Melo et al 2007;Pucci et al 2008;Hoffmann et al 2011;Alvarez et al 2014;Wu et al 2015;Moff ett et al 2016).…”

Field fertility of liquid stored and cryopreserved flow cytometrically sex‐sorted stallion sperm

“…insemination cycles) was achieved. Although previous studies have shown that cooled liquid storage of stallion semen prior to cryopreservation is not detrimental to motility or fertility [24][25][26], none of these studies extended beyond initial pregnancy detection at 15 days. For logistical reasons, the storage of sperm for transport prior to sex-sorting was necessary and reflects the reality of a commercial situation in which the mare and stallion cannot be housed at the sorting facility.…”

“…Also, using liquid stored, sex-sorted, cryopreserved stallion sperm, a per cycle conception rate of 27% (3 of 11 80 KMT I- The recovered embryos were not transferred to recipient mares. It has previously been shown that cold storage of stallion semen for 12-24 h prior to freezing is not detrimental to sperm motility or to conception rates as assessed by ultrasonography 15 days after insemination [4,[24][25][26] and that liquid storage of sperm either prior to or following sorting also does not appear to be appreciably detrimental to conception rates [4,27] or sperm quality [28]. c One foal resulted from a conceptus that was allowed to develop to term and one from an embryo transferred to a recipient mare.…”

“…For logistical reasons, the storage of sperm for transport prior to sex-sorting was necessary and reflects the reality of a commercial situation in which the mare and stallion cannot be housed at the sorting facility. It has previously been shown that cold storage of stallion semen for 12-24 h prior to freezing is not detrimental to sperm motility or to conception rates as assessed by ultrasonography 15 days after insemination [4,[24][25][26] and that liquid storage of sperm either prior to or following sorting also does not appear to be appreciably detrimental to conception rates [4,27] or sperm quality [28]. Our findings show that sperm fertility, at least in terms of conception rates, can be maintained at acceptable levels after even longer periods of liquid storage, both before and after sorting.…”

“…The literature suggests that the development of embryos derived from sex-sorted sperm is delayed [30][31][32][33] and that liquid stored, sex-sorted, cryopreserved stallion sperm have DNA fragmentation rates exceeding 70% [12,13], which while not necessarily detrimental to the ability of the sperm to fertilise the oocyte, may lead to post fertilisation failure [34,35]. Although previous studies have shown that cooled liquid storage of stallion semen prior to cryopreservation is not detrimental to motility or fertility [24][25][26], none of these studies extended beyond initial pregnancy detection at 15 days. Around 7.5% of all conceptions in mares ('natural' or AI) result in EED [36], with 63% of these losses occurring between 15 and 45 days after ovulation.…”