title: Lamb production using superovulation, embryo bisection, and transfer.
abstract: In this study, 39 embryos from donor ewes superovulated with follicle stimulating hormone-pituitary (FSH-P) were bisected to produce pairs of monozygotic twin lambs for experimentation. Each pair obtained by bisecting 8-, 9- or 10-day-old embryos was immediately transferred surgically into a recipient ewe at the same physiological stage. Of the 39 recipients which received a pair of half-embryos by transfer into the uterine horn ipsilateral to the corpus luteum, 28 (72%) lambed. Eighteen of 28 recipients lambing (64%) produced pairs, i.e., 7 male and 11 female pairs. Ten of 28 lambings produced a single lamb, i.e., six males and four females. Overall yield (the number of lambs produced in relation to the number of embryos used) was 118%. This percentage tended to increase, depending on the day of collection (Day 8, 100%; Day 9, 118%; and Day 10, 131%).
authors.affiliation: I.N.R.A., Station de Physiologie Animale, 78350 Jouy-en-Josas, France.
authors.forename: P
authors.initials: P
authors.lastname: Chesné
authors.forename: G
authors.initials: G
authors.lastname: Colas
authors.forename: Y
authors.initials: Y
authors.lastname: Cognié
authors.forename: Y
authors.initials: Y
authors.lastname: Guérin
authors.forename: C
authors.initials: C
authors.lastname: Sévellec