Determinants of survival of the bovine blastocyst to cryopreservation stress: treatment with colony stimulating factor 2 during the morula-to-blastocyst transition and embryo sex

Table 2 Effect of colony stimulating factor 2 (CSF2) and sex on survival of blastocysts following vitrification as evaluated by re-expansion of the blastocoele and initiation of hatching from the zona pellucida after 24 h of culture post-thawing

Treatment	Sex	Number of blastocysts	Re-expansion (%)^a	Number of blastocysts^b	Hatching (%)^a
Vehicle	Female	94	84.0 ± 3.8	83	52.5 ± 6.9
CSF2	Female	115	87.8 ± 3.0	102	51.1 ± 5.8
Vehicle	Male	142	82.4 ± 3.2	125	58.8 ± 6.5
CSF2	Male	149	84.6 ± 3.0	137	58.7 ± 5.8
P values
CSF2			0.525		0.882
Sex			0.582		0.160
CSF2 x sex			0.810		0.902

^aData are least-squares means ± SEM
^bNumber is lower than for re-expansion because embryos that were hatching or hatched before vitrification were excluded

ISSN: 2662-4044