title: Pregnancy per AI in Holstein heifers inseminated with sex-selected or conventional semen after estrus detection or timed-AI.
abstract: This study compared pregnancy per AI (P/AI) of heifers inseminated with sex-selected or conventional semen after estrus detection (ED) or timed-AI (TAI). Heifers in the ED group received 2 treatments with prostaglandin F2α 14 d apart and those in the TAI group received a modified 5-day Co-synch protocol plus an intravaginal progesterone releasing insert device (PRID) and were inseminated 72 h after PRID removal. Overall P/AI were 69.2% (74/107) and 64.1% (75/117) for conventional and sex-selected semen (P> 0.05). Although P/AI in ED heifers following the use of conventional semen were numerically higher (75.0%versus63.6%), P/AI with sex-selected semen were almost identical (65.0%versus63.2%) for ED and TAI heifers. Pregnancy losses from first pregnancy diagnosis to term did not differ between ED and TAI heifers (6.0%versus11.3%). In summary, heifers subjected to TAI with sex-selected semen following the application of a modified 5-day Co-synch plus PRID protocol had acceptable P/AI.
authors.affiliation: Livestock Research Branch, Alberta Agriculture and Forestry, Edmonton, Alberta T6H 5T6 (Colazo); Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4 (Mapletoft).
authors.forename: Marcos G
authors.initials: MG
authors.lastname: Colazo
authors.affiliation: Livestock Research Branch, Alberta Agriculture and Forestry, Edmonton, Alberta T6H 5T6 (Colazo); Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4 (Mapletoft).
authors.forename: Reuben J
authors.initials: RJ
authors.lastname: Mapletoft
mesh_terms: D000034:Abortion, Veterinary; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003008:Cloprostenol / Q000008:administration & dosage; D015237:Dinoprost / Q000008:administration & dosage; D004972:Estrus Detection; D005260:Female; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011374:Progesterone / Q000008:administration & dosage; D012743:Sex Preselection / Q000662:veterinary
chemical_list: D003008:Cloprostenol; D011374:Progesterone; D015237:Dinoprost