title: Freezability and fertility results with uncentrifuged stallion semen.
abstract: The first (1 to 3) sperm-rich fractions of the ejaculate were collected from 4 stallions using an open-ended vagina. The volume of the collected fractions was 12 +/- 8 ml with a density of 475 +/- 200 million spermatozoa/ml. Before freezing, the semen was diluted with a skim-milk based extender 1:1 to 1:8 (volume of semen: volume of extender), depending on the initial sperm concentration to achieve a final concentration of 100 million/ml. The total number of spermatozoa in an insemination dose ranged from 0.7 to 1 billion spermatozoa. Within 12 h after ovulation, 48 mares were inseminated in 70 cycles. The total single-cycle pregnancy rate at day 21 was 24%, but varied from 10% to 33% per cycle among the stallions.
authors.affiliation: Department of Biochemistry & Biotechnology, University of Kuopio, Ypäjä, Finland.
authors.forename: M L
authors.initials: ML
authors.lastname: Heiskanen
authors.forename: L
authors.initials: L
authors.lastname: Hilden
authors.forename: S
authors.initials: S
authors.lastname: Hyyppä
authors.forename: A
authors.initials: A
authors.lastname: Kangasniemi
authors.forename: A
authors.initials: A
authors.lastname: Pirhonen
authors.forename: P H
authors.initials: PH
authors.lastname: Mäenpää
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000662:veterinary*; D005260:Female; D005298:Fertility / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D007315:Insemination, Artificial / Q000662:veterinary; D008297:Male; D011247:Pregnancy; D012662:Semen Preservation / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*