Table 3. Viability and hatching rates of poor-quality bovine embryos produced in vivo by artificial insemination, following storage at 4°C for 168 h in medium 199 plus 50% FBS, supplemented with various concentrations of HEPES.
| Concentration of HEPES (mM) | pH* | No. of embryos | No. (%) of viable embryos | No. (%) of hatching embryos |
|---|---|---|---|---|
| 0 | 7.7 | 30 | 3 (10)a | 1 (3)a |
| 12.5 | 7.4 | 35 | 19 (54)b | 9 (26)b |
| 25.0 | 7.0 | 36 | 25 (69)b | 13 (36)b |
| 50 | 6.8 | 30 | 22 (73)b | 10 (33)b |
| 100 | 6.9 | 20 | 13 (65)b | 4 (20)a,b |
a, bData with different superscript letters differ significantly (P < 0.05).
*Medium pH at the end of chilling preservation.