Repeatability of superovulatory response to successive FSH treatments in Merino sheep

摘要: Abstract The efficiency of a multiple ovulation and embryo transfer program depends on the recovery large number viable embryos per donor ewe at each successive superovulatory treatment. Embryo production, however, is characterized by high individual variability in ovarian response to hormonal This study evaluated repeatability following three treatments 10 four-year-old Merino ewes over short period time. Oestrus was synchronized using an intravaginal progesterone pessary inserted Day 0 removed 14. FSH administered induce superovulation declining doses twice daily 3 days as 2(18 + 14 + 8) = 80 mg total commencing 12 after insertion. A dose 200 IU eCG removal. Vasectomized rams were used for heat detection laparoscopic AI performed 12 h oestrus detection. Surgical 8 removal, which prostaglandin next procedures began 5 later giving 27-day interval between recoveries. Ovulation rates (mean ± SEM) 13.8 ± 2.2, 12.1 ± 2.2 12.0 ± 2.2 (NS); recovered 8.3 ± 1.4, 6.3 ± 1.4 3.9 ± 1.4 (P = 0.06), respectively. Consequently, declined from 66.1 ± 7.5% first 41.4 ± 7.5 34.5 ± 7.5% second third recoveries (P = 0.04). r = 0.84 (P