title: Sperm pre-incubation prior to insemination affects the sex ratio of bovine embryos produced in vitro.
abstract: The objective of the present study was to determine whether sperm incubation prior to oocyte insemination in vitro affects the sex ratio of resulting blastocyst. Cumulus-oocyte-complexes (COCs) collected from slaughterhouse ovaries were matured in vitro and inseminated with frozen-thawed semen of three proven artificial insemination (AI) bulls pre-incubated in vitro in Sperm-Talp for 6 and 24 h. On day-9 blastocysts were collected and processed for sex determination. More than 80% of blastocyst were successfully sexed. There were no significant differences in cleavage and blastocyst rates using sperm pre-incubated for 6 h as compared with the 0-h pre-incubation control group. The cleavage and blastocyst rates were significantly lower in the 24-h pre-incubation group. The male to female ratio, when compared with the theoretical 1 : 1, differed significantly in favour of females among hatched (viable) blastocysts derived from sperm pre-incubated for 24 h prior to insemination as well as among all blastocytsts in the 6-h group. Moreover, when the sperm treatment was considered, the sex ratio was affected only among hatched blastocysts in 24-h pre-incubation group. It was concluded that prolonged sperm pre-incubation influences the rate of development and the sex ratio among hatched blastocysts.
authors.affiliation: Department of Genetics and Animal Breeding, August Cieszkowski Agricultural University of Poznan, Poznan, Poland. lechniak@jay.au.poznan.pl
authors.forename: D
authors.initials: D
authors.lastname: Lechniak
authors.forename: T
authors.initials: T
authors.lastname: Strabel
authors.forename: D
authors.initials: D
authors.lastname: Bousquet
authors.forename: A W
authors.initials: AW
authors.lastname: King
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002417:Cattle / Q000502:physiology*; D046508:Culture Techniques; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D012662:Semen Preservation; D019849:Sex Determination Processes; D012744:Sex Ratio; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000502:physiology*