A total of 3427 goat oocytes were used in this study to identify possible differences during
in vitro embryo production from slaughterhouse or laparoscopic ovum pick up (LOPU)
oocytes. In experiment 1, one complex, one semi-defined, and one simplified IVM media
were compared using slaughterhouse oocytes. In experiment 2, we checked the effect of
oocyte origin (slaughterhouse or LOPU) on the kinetics of maturation (18 vs. 22 vs.
26 hours) when submitted to semi-defined or simplified media. In experiment 3, we
determined the differences in embryo development between slaughterhouse and LOPU
oocytes when submitted to both media and then to IVF or parthenogenetic activation (PA).
Embryos from all groups were vitrified, and their viability evaluated in vitro after thawing.
In experiment 1, no difference (P > 0.05) was detected among treatments for maturation
rate (metaphase II [MII]; 88% on average), cleavage (72%), blastocyst from the initial
number of cumulus oocyte complexes (46%) or from the cleaved ones (63%), hatching rate
(69%), and the total number of blastomeres (187). In experiment 2, there was no difference
of MII rate between slaughterhouse oocytes cultured for 18 or 22 hours, whereas the MII
rate increased significantly (P < 0.05) between 18 and 22 hours for LOPU oocytes in the
simplified medium. Moreover, slaughterhouse oocytes cultured in simplified medium
matured significantly faster than LOPU oocytes at 18 and 22 hours (P < 0.05). In experiment 3, cleavage rate was significantly greater (P < 0.001) in all four groups of embryos
produced by PA than IVF. Interestingly, PA reached similar rates for slaughterhouse oocytes
cultured in both media, but improved (P < 0.05) the cleavage rate of LOPU oocytes.
Slaughterhouse oocytes had acceptable cleavage rate after IVF (w67%), whereas LOPU
oocytes displayed a lower one (w38%), in contrast to cleavage after PA. The percentage of
blastocysts in relation to cleaved embryos was not affected by the origin of the oocytes (P
> 0.05). Therefore, slaughterhouse oocytes developed a greater proportion of blastocysts
than LOPU ones, expressed as the percentage of total cumulus oocyte complexes entering
to IVM. Vitrified-thawed blastocysts presented similar survival and hatching rates between
the oocyte origin, media, or method of activation. In conclusion, slaughterhouse and LOPU
derived oocytes may have different IVM kinetics and require different IVM and IVF