title: Fertility response of artificial insemination methods in sheep with fresh and frozen-thawed semen.
abstract: The aim of this study was to evaluate the fertility response of artificial insemination (AI) methods with fresh and frozen sperm in sheep. In experiment 1, one hundred and fifty fat tailed Zandi ewes were assigned into 3 equal groups and inseminated with three AI methods consisting of vaginal, laparoscopic and trans-cervical AI with fresh semen. In experiment 2, a factorial study (3 AI methods × 2 extenders) was used to analyze the effects of three AI methods and two freezing extenders containing soybean lecithin (SL) or Egg yolk (EY) on reproductive performance of 300 fat tailed Zandi ewes. Also, total motility, progressive motility, viability and lipid peroxidation of semen were evaluated after freeze-thawing in two extenders. In result, there was no significant difference among three AI methods when fresh semen was used. In experiment 2, the highest percentage of pregnancy rate, parturition rate and lambing rate were obtained in laparoscopic AI group (P < 0.05). Although pregnancy rate, parturition rate and lambing rate in trans-cervical group were higher (P < 0.05) than vaginal group, the results were not as high as laparoscopic group. No difference was observed between SL and EY extenders and their performance was close to each other. It can be concluded that although no difference was observed on reproductive performance for fresh semen, trans-cervical AI was more efficient than vaginal method when frozen-thawed semen was used, but its efficiency was not as high as laparoscopic method. Also, SL extender can be an efficient alternative extender to preserve ram sperm during cryopreservation procedure without adverse effects of EY.
authors.affiliation: Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Masoudi
authors.affiliation: Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Electronic address: azareh@ut.ac.ir.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Zare Shahneh
authors.affiliation: Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Armin
authors.initials: A
authors.lastname: Towhidi
authors.affiliation: Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Kohram
authors.affiliation: The Breeding Station of Zandi Sheep, Pishwa, Varamin, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Akbarisharif
authors.affiliation: Department of Poultry Science, Faculty of Agriculture, University of Tarbiat Modares, Tehran, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Sharafi
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004530:Egg Yolk / Q000378:metabolism; D005260:Female; D005298:Fertility / Q000502:physiology; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D054709:Lecithins / Q000494:pharmacology; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D012098:Reproduction; D012661:Semen / Q000502:physiology*; D012662:Semen Preservation / Q000662:veterinary*; D012756:Sheep; D030262:Soybean Proteins / Q000494:pharmacology; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D003451:Cryoprotective Agents; D054709:Lecithins; D030262:Soybean Proteins
keywords: Artificial insemination; Frozen-thawed semen; Reproductive performance; Zandi ewes