title: Quality and fertilizing ability in vivo of sex-sorted stallion spermatozoa.
abstract: Little information is available on the quality of stallion spermatozoa after sex sorting. The objectives of the present study were to assess the quality of sex-sorted stallion spermatozoa and determine its fertilizing ability after hysteroscopic low dose insemination. Ejaculates from four stallions were collected and sorted by a MoFlo SX flow cytometer/sperm sorter. Before and after sorting, spermatozoa were evaluated for motility by Computer Assisted Sperm Analysis, viability (SYBR 14-propidium iodide), mitochondrial function (JC-1) and acrosomal status (fluorescein isothiocyanate Pisum sativum agglutinin conjugated). A fertility trial was carried out on four mares (seven oestrous cycles) by hysteroscopic insemination, depositing 5 x 10(6) X-bearing spermatozoa. Sex sorting resulted in a significant decrease (p < 0.001) in all motility characteristics. Sperm viability and percentage of spermatozoa with functional mitochondria were not affected by the sorting process, while the percentage of reacted spermatozoa was higher (p < 0.01) for non-sorted than sorted spermatozoa. Pregnancy rate was 28.6% (2/7) after low dose hysteroscopic insemination. Only one pregnancy was carried to term with the birth of a healthy filly. In conclusion, despite the reduction in sperm motility, sex sorting did not impair stallion sperm viability and mitochondrial activity immediately post-thaw; moreover, the sexed spermatozoa retained the ability to fertilize in vivo.
authors.affiliation: Veterinary Clinical Department, University of Bologna, Bologna, Italy. gaetano.mari@unibo.it
authors.forename: G
authors.initials: G
authors.lastname: Mari
authors.forename: G
authors.initials: G
authors.lastname: Rizzato
authors.forename: B
authors.initials: B
authors.lastname: Merlo
authors.forename: E
authors.initials: E
authors.lastname: Iacono
authors.forename: D
authors.initials: D
authors.lastname: Bucci
authors.forename: E
authors.initials: E
authors.lastname: Seren
authors.forename: C
authors.initials: C
authors.lastname: Tamanini
authors.forename: G
authors.initials: G
authors.lastname: Galeati
authors.forename: M
authors.initials: M
authors.lastname: Spinaci
mesh_terms: D020101:Acrosome Reaction; D000818:Animals; D005260:Female; D006736:Horses / Q000502:physiology*; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D012662:Semen Preservation / Q000662:veterinary; D012743:Sex Preselection / Q000662:veterinary*; D013094:Spermatozoa