title: The number of spermatozoa, the number of ovulations per ewe, and immunization against androstenedione affect fertility and prolificacy of sheep.
abstract: Ewes that were untreated, fed lupins or fed lupins and immunized against androstenedione were artificially inseminated. The percentage of ewes pregnant at 36-45 days after insemination (fertility) was 8% higher in ewes that had more than one ovulation than in those that had only one ovulation. Maximum fertility was achieved with 50 x 10(6) spermatozoa and this did not vary with the number of ovulations that ewes had. Among the pregnant, twin-ovulating ewes, embryo survival increased as the number of spermatozoa inseminated increased from 25 x 10(6) to 400 x 10(6). Immunization of ewes against androstenedione increased ovulation rate but reduced fertility, and reduced embryo survival among twin-ovulation ewes.
authors.affiliation: Department of Animal Science, University of Western Australia, Nedlands.
authors.forename: A W
authors.initials: AW
authors.lastname: Cameron
authors.forename: C M
authors.initials: CM
authors.lastname: Oldham
authors.forename: I J
authors.initials: IJ
authors.lastname: Fairnie
authors.forename: E J
authors.initials: EJ
authors.lastname: Keogh
authors.forename: D R
authors.initials: DR
authors.lastname: Lindsay
mesh_terms: D000735:Androstenedione / Q000502:physiology*; D000818:Animals; D005260:Female; D005298:Fertility; D005313:Fetal Death; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D010060:Ovulation; D011247:Pregnancy; D012756:Sheep; D013094:Spermatozoa / Q000502:physiology
chemical_list: D000735:Androstenedione