Control of ovulation with a GnRH agonist after superstimulation of follicular growth in buffalo: fertilization and embryo recovery.
The potential to use a GnRH agonist bioimplant and injection of exogenous LH to control the time of ovulation in a multiple ovulation and embryo transfer (MOET) protocol was examined in buffalo. Mixed-parity buffalo (Bubalus bubalis; 4-15-year-old; 529 +/- 13 kg LW) were randomly assigned to one of five groups (n = 6): Group 1, conventional MOET protocol; Group 2, conventional MOET with 12 h delay in injection of PGF2alpha; Group 3, implanted with GnRH agonist to block the preovulatory surge release of LH; Group 4, implanted with GnRH agonist and injected with exogenous LH (Lutropin, 25 mg) 24 h after 4 days of superstimulation with FSH; Group 5, implanted with GnRH agonist and injected with LH 36 h after superstimulation with FSH. Ovarian follicular growth in all buffaloes was stimulated by treatment with FSH (Folltropin-V, 200 mg) administered over 4 days, and was monitored by ovarian ultrasonography. At the time of estrus, the number of follicles >8 mm was greater (P < 0.05) for buffaloes in Group 2 (12.8) than for buffaloes in Groups 1(8.5), 3 (7.3), 4 (6.1) and 5 (6.8), which did not differ. All buffaloes were mated by Al after spontaneous (Groups 1-3) or induced (Groups 4 and 5) ovulation. The respective number of buffalo that ovulated, number of corpora lutea, ovulation rate (%), and embryos + oocytes recovered were: Group 1 (2, 1.8 +/- 1.6, 18.0 +/- 13.6, 0.2 +/- 0.2); Group 2 (4,6.1 +/- 2.9, 40.5 +/- 17.5, 3.7 +/- 2.1); Group 3 (0, 0, 0, 0); Group4 (6, 4.3 +/- 1.2, 69.3 +/- 14.2, 2.0 +/- 0.9); and Group 5 (1, 2.5 +/- 2.5, 15.5 +/- 15.5, 2.1 +/- 2.1). All buffaloes in Group 4 ovulated after injection of LH and had a relatively high ovulation rate (69%) and embryo recovery (46%). It has been shown that the GnRH agonist-LH protocol can be used to improve the efficiency of MOET in buffalo.
Carvalho
Nelcio A T
NA
Department of Animal Reproduction, Faculty of Veterinary Medicine, University of Sao Paulo, Rua Prof. Orlando Marques de Paiva, 87, CEP, 05508-000 Sao Paulo, SP Brazil.
Baruselli
Pietro S
PS
Zicarelli
Luigi
L
Madureira
Edward H
EH
Visintin
Jose A
JA
D'Occhio
Michael J
MJ
D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D004343:Drug Implants; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage; D007315:Insemination, Artificial / Q000662:veterinary; D007986:Luteinizing Hormone / Q000008:administration & dosage; D006080:Ovarian Follicle / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D010053:Ovary / Q000000981:diagnostic imaging; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000662:veterinary*; D017329:Triptorelin Pamoate / Q000008:administration & dosage* / Q000031:analogs & derivatives; D014463:Ultrasonography
D004343:Drug Implants; D017329:Triptorelin Pamoate; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C066438:deslorelin