Caprine blastocyst development after in vitro fertilization with spermatozoa frozen in different extenders.
The feasibility of using frozen-thawed semen in caprine IVF outside the breeding season was investigated. Electroejaculated spermatozoa from a Nubian buck were washed twice and then frozen in skim milk- or in egg yolk-based extenders. Goat oocytes were matured and inseminated by frozen-thawed spermatozoa selected by swim-up. In vitro fertilization was performed in a modified defined medium (mDM), altered experimentally, for 24 h. Embryos were cultured in 50 microL of c-SOF + NEA for 9 d. The percentages of oocytes exposed to heparin-capacitated spermatozoa, (previously cryopreserved in skim milk-based extender) that cleaved, reached morula, blastocyst and expanded blastocyst stages were 82.8, 57.1, 35.7 and 30.0%, respectively. Without heparin treatment the rates for cleavage, morula, blastocyst and expanded blastocyst stages were 44.3, 31.4, 18.6 and 8.6%, respectively. Therefore, heparin treatment was included in sperm capacitation. Use of spermatozoa with BSA in the IVF medium yielded no cleavage. Although extenders containing 8 to 20% egg yolk enabled good sperm motility after cryopreservation, in vitro fertilizing ability was compromised under our conditions. By contrast, semen commercially processed in season in an egg yolk-based diluent remained effective for IVF. The highest proportion of blastocysts resulted from the use of spermatozoa diluted in a skim milk extender, heparin capacitation, and insemination in medium containing lamb serum.
Keskintepe
L
L
Department of Physiology & Pharmacology, College of Veterinary Medicine, University of Georgia, Athens 30602, USA.
Simplicio
A A
AA
Brackett
B G
BG
D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004530:Egg Yolk / Q000502:physiology; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D006041:Goats / Q000196:embryology* / Q000502:physiology; D006493:Heparin / Q000737:chemistry; D008297:Male; D008892:Milk / Q000502:physiology; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000502:physiology; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013075:Sperm Capacitation / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology
D006493:Heparin