Maturation and fertilization of pig follicular oocytes cultured in pig amniotic fluid

Three experiments were conducted to assess the ability of pig amniotic fluid to support oocyte maturation and developmental competence. In Experiment 1, pig follicular oocytes were cultured in pig amniotic fluid (PAF) containing luteinizing hormone (LH) and estradiol-17beta for 28 to 48 h, during which time the maturational stages of the oocytes were observed. While the maturation rates to the second metaphase were high (62%) after 33 h of culture, the rates decreased (24 to 30%) when oocytes were cultured in PAF without LH. In Experiment 2, oocytes matured in PAF were inseminated in vitro with fresh semen from three boars. The spermatozoal penetration rate ranged from 42 to 100%, and 15 to 40% of the penetrated oocytes had both male and female pronuclei. In Experiment 3, oocytes were cultured for 46 to 47 h in PAF and transferred to the oviducts of inseminated gilts. Eighteen of 136 embryos recovered from the uteri 128 h after oocyte transfer developed to the morula and blastocyst stages. The embryos were transferred to a recipient, and two piglets were born (one live and one dead) of the resultant pregnancy. These results indicate that PAF can be used for maturation of pig follicular oocytes and that oocytes cultured in PAF have the developmental capacity to become piglets.