In vitro fertilization (IVF) in straws and a short gamete coincubation time improves the efficiency of porcine IVF.
The present study was designed to evaluate three different in vitro fertilization (IVF) systems: a straw-IVF system with 10 min of coincubation, a straw-IVF system with 6-h coincubation and the microdrop-IVF system with 6-h coincubation (the traditional IVF system used routinely in most of IVF laboratories) in an attempt to reduce polyspermic penetration (Experiment 1). When the straw-IVF system was tested in combination with two coincubation times, the use of 10 min of coincubation significantly increased (p < 0.001) the penetration rate and the efficiency of fertilization (67.7 +/- 6.4% vs 31.9 +/- 6.5% and 41.5 +/- 2.5% vs 17.6 +/- 2.5% for 10 min and 6 h, respectively), while there were no significant differences in the incidence of monospermy between both systems (64.3 +/- 5.1% and 67.7 +/- 3.4%, for 10 min and 6 h, respectively). The penetration rate in the 6-h microdrop-IVF system was higher (93.8 +/- 3.6%; p < 0.001) compared with the 10-min straw-IVF system (67.7 +/- 6.4%), however, monospermy was severely reduced (25.0 +/- 4.3% vs 67.7 +/- 3.4%, for the 6-h microdrop-IVF system and 10-min straw-IVF system, respectively). The efficiency of the IVF showed similar values between microdrop and 6-h straw-IVF systems, but efficiency was significantly improved (p < 0.05) when the 10-min straw-IVF system was used. Experiment 2 was designed to compare porcine in vitro embryo production in two IVF systems, the 6-h microdrop-IVF system (1000 sperm per oocyte) and 10-min straw-IVF system (30 000 sperm per oocyte). The blastocyst formation rates tended (p = 0.06) to be higher when the 10-min straw-IVF system was used compared with the 6-h microdrop-IVF system. In addition, the number of total cells per blastocyst increased significantly (p < 0.05) in the 10-min straw-IVF system. These results showed that the 10-min straw-IVF system is an effective way to decrease polyspermic penetration, and improve the efficiency of fertilization and the quality of blastocysts in terms of cell number per embryo.
Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain.
C
C
Almiñana
M A
MA
Gil
C
C
Cuello
I
I
Caballero
J
J
Roca
J M
JM
Vazquez
E A
EA
Martinez
D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D015925:Cryopreservation / Q000662:veterinary; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary*; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D008297:Male; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D018873:Pregnancy Rate; D012662:Semen Preservation / Q000662:veterinary; D013081:Sperm Motility / Q000502:physiology; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology; D013552:Swine / Q000502:physiology*; D013997:Time Factors