Abstract :
This study was initiated to investigate the effect of culture conditions on the in vitro development
of cloned goat embryos, as well as the pregnancy and delivery success after embryo
transfer. The fused embryos were randomly distributed to four culture groups: (i) 72 h in
G1 medium then 96 h in G2 medium (group G1/G2); (ii) 168 h in mSOFBSA (group mSOFBSA);
(iii) 72 h in mSOFBSA then 96 h in mSOFBSA supplemented with 10% FBS (group
mSOFBSA-FBS); (iv) 168 h in mSOFBSA supplemented with 10% FBS (group mSOFFBS). A
higher proportion of reconstructed embryos developed to the hatching blastocyst stage
in the mSOFBSA group, compared to the G1/G2 group (30.8% vs. 11.4%; P < 0.05). Furthermore,
supplementation of 10% FBS to mSOFBSA at the beginning of culture, or 72 h later
both significantly improved the hatching rates, compared to the control group (48.9%, 51.2%
vs. 28.2%, respectively; P < 0.05). The pregnancy rate following the transfer of one-cell stage
embryos was higher than that of in vitro cultured blastocysts (32.0% vs. 6.9%; P < 0.05). However,
no significant differences were observed regarding NT efficiency, based on the number
of embryos transferred between the two groups (2.0% and 1.3%, respectively). Results suggest
that cloned goat embryos cultured to the blastocyst stage in vitro in mSOFFBS may
develop to term.
