Fœtal programming and epigenetics: how important are they for the equine species?
Résumé
Single layer centrifugation (SLC) with Androcoll-E™ enables a better sub-population ofspermatozoa to be selected from stallion ejaculates. Installions with fertility problems, SLC-treated sperm seems to result in normal pregnancy rates. Since no studies have been performed on the effect of Androcol!-ETM treatment on pregnancy rates obtained from fertile stallions, this study was designed to investigate whether SLC could be used to enbance fertility rates of normal stallion. Ejaculates obtained from a SIRE were used to study quality and longevity of the sperm recovered after centrifugation in Androcol!-ETM as weil as pregnancy rates obtained after AI with and without SLC-centrifuged sperm. The sperm's characteristics not recovered by SLC-treatment were also investigated and results were compared by ANOVA. SLC-recovered sperm presented the highest percentage oflive cells and membranes osmotically active (HOS test) while the highest percentage of sperm with high mitochondrial potential (il'JI mit; JC-1) and DNA integrity (SCD test) was retained in the upper layer. Sperm motility in SLC-selected samples cooled for 72 h didn't differ from non SLC-selected sperm. A crosstabs procedure (chi-square test, x2) was used and per cycle fertility obtained with Androcol!-ETM treated semen (78%, 9 mares; 7 cycles DG+) didn't differ (x2(2)00; P=0.527; n=18) from per cycle fertility obtained with non SLC-treated sperm (89%; 9 mares; 8 cycles DG+). In conclusion, our results suggest thal fertility is independent oftreatment with Androcol!-ETM. Answer to REviwers: We have no data with sub fertille stallions regarding in vivo and in vitro comparison.