Blastocyst formation of pig embryos derived from in vitro fertilization of in vitro matured pig oocytes in the amniotic fluid of a developing chick embryo
Ocampo, M.B.; Ocampo, L.C.; Mori, T.; Ueda, J.; Shimizu, H.; Kanagawa, H.
Animal Reproduction Science 37(1): 65-73
In this study, the acquisition of developmental competence of early-stage pig embryos derived from in vitro fertilization of in vitro matured pig oocytes was determined by culturing in a modified Whittens medium (mWM) or amniotic fluid of a developing chick embryo (CEAm fluid). Of 1080 oocytes inseminated, 420 were fixed after 15 h revealing a nuclear maturation rate of 95.2% (400/420) with a fertilization rate of 84.3% (354/420). The monospermic fertilization rate was 36.4% (129/354). Of 660 oocytes that were allowed to continue development, 74.2% (490/660) cleaved. Of these, 220 and 157 embryos were cultured in mWM and CEAm fluid with 19.5% and 25.7% progressing to blastocyst stage, respectively. The mean (+- standard error of the mean) cell number of blastocyst stage embryos derived from CEAm fluid (52.0 +- 3.0) was significantly higher (P lt 0.001) than those obtained from mWM (39.0 +- 1.7). The results suggest that CEAm fluid is a better in vitro culture system for pig embryo development than mWM.