title: The effect of timing of laparoscopic insemination in superovulated ewes, with or without sedation, on the recovery of embryos, their stage of development and subsequent viability.
abstract: Twenty ewes were used as donors in a 2 x 2 factorial design experiment to investigate the effects of two different insemination times (48 vs 60 h after pessary withdrawal), with or without sedation, on the ovum recovery rate 5 d after insemination, the proportion of transferable embryos recovered, and the subsequent survival rate of embryos transferred to recipients. The ovum recovery rate following intrauterine insemination at 48 h after progestagen pessary withdrawal was 63.8 and 53.4% for sedated and nonsedated control ewes, respectively. Following intrauterine insemination at 60 h the corresponding values for sedated and control ewes were 72.6 and 73.9%, respectively. The proportion of transferable quality embryos recovered was not affected by sedation but was improved by insemination at 48 h rather than 60 h after pessary withdrawal (100 vs 35.4%). Embryo survival following laparoscopic transfer to recipients from donor ewes inseminated at 48 h, with or without sedation was 38.8% (7/18) and 50% (7/14), respectively. Following intrauterine insemination of the donors at 60 h, the survival rate in recipients was reduced for embryos transferred from both the sedated and control ewes to 6.25% (1/16) and 36.3% (4/11). It is concluded that delaying the timing of intrauterine insemination relative to pessary withdrawal and the use of acepromazine maleate as a sedative at the time of insemination are deleterious to embryo development and subsequent viability.
authors.affiliation: Rowett Research Institute, Greenburn Road, Bucksburn Aberdeen, AB2 9SB, Scotland.
authors.forename: C L
authors.initials: CL
authors.lastname: Scudamore
authors.forename: J J
authors.initials: JJ
authors.lastname: Robinson
authors.forename: R P
authors.initials: RP
authors.lastname: Aitken