title: Effect of deposition site and sperm number on the fertility of sheep inseminated with liquid semen.
abstract: The effect of the deposition site and the numbers of sperm on the fertility of sheep was tested in a field trial in which 1292 Norwegian crossbred ewes aged between six months and five-and-a-half years from 52 farms were inseminated with liquid semen after natural oestrus. Cervical insemination with 150 x 10(6) and 75 x 10(6) spermatozoa resulted in 25-day non-return rates of 63.7 and 56.1 per cent, and vaginal insemination gave non-return rates of 63.3 and 56.6 per cent, respectively. There was no significant difference between the cervical and vaginal inseminations, but the inseminations with 150 x 10(6) spermatozoa gave significantly higher non-return rates (P=0.004). There were significant differences between the non-return rates for different rams (P<0.0001) and farmers (P=0.0002) but the age of the ewe had no significant effect.
authors.affiliation: Team Semin, Oslo, Norway.
authors.forename: H
authors.initials: H
authors.lastname: Paulenz
authors.forename: T
authors.initials: T
authors.lastname: Adnøy
authors.forename: O H
authors.initials: OH
authors.lastname: Fossen
authors.forename: L
authors.initials: L
authors.lastname: Söderquist
authors.forename: K Andersen
authors.initials: KA
authors.lastname: Berg
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D005260:Female; D005298:Fertility; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D008297:Male; D009664:Norway; D012756:Sheep