118 Replacing ovum pickup media for in vitro embryo production in cattle: quest to reduce the cost of production of embryos

Ovum pickup and in vitro embryo production (OPU-IVEP) technology is still in its infancy in India, with limited acceptance among farmers, mainly due to high cost and poor efficiency. Presently, imported media constitute around 60% of the cost of embryo production. Efforts were made to replace OPU media with less expensive alternatives, and the data shown here are from an ongoing experiment with promising results. The OPU media were developed by adding injectable sodium heparin (50 µg/mL) in embryo flushing media containing Zwitter ion buffer (EmXcell, IMV technologies). The media so prepared in-house (OPU-IMV) were tested against commercially available OPU media from IVF Bioscience, UK (OPU-IVFB). The in-house developed media were ∼3–4 times cheaper than the commercial media listed here. On each day of OPU, Bos indicus and Bos taurus-indicus donor cows were randomly assigned to either OPU-IMV or OPU-IVFB media groups and a total of 201 OPU-IVEP cycles were performed. A total of 33 donors were involved in this study and an average of 6.1 OPUs/donor were performed during the 15 months of the period of study. On each collection day, an average of three OPUs were performed. OPU-IMV media were used in 24 OPUs (n = 24) whereas OPU-IVFB media were used in 177 OPUs (n = 177). The OPU-IVEP cycles in both groups were performed during the same period of time. The OPU-IVEP procedure in both groups was performed using already-standardised laboratory procedures. Oocytes, aspirated using standard equipment, were subjected to IVM (22 h in 5% CO₂ in air in maximum humidity at 38.5°C), IVF (22 h in 5% CO₂ in air in maximum humidity at 38.5°C) and IVC (7 days from IVF in 5% CO₂, 5% O₂ in maximum humidity at 38.5°C). All the other media used for OPU-IVEP were procured from IVF Bioscience, UK. The cleavage rate was calculated by dividing the total number of oocytes cleaved by total number of oocytes kept for IVC. Similarly, the blastocyst rate was calculated by dividing the total number of blastocysts by total number of oocytes kept for IVC. Descriptive statistics were calculated for oocyte recovery/OPU, cleavage rate, blastocyst rate, and embryos/OPU for both OPU media, and means were represented as mean + s.e.m. Means were compared between two different groups of OPU media by Student’s t-test and means were considered differing significantly if P < 0.05. The average number of oocytes aspirated/OPU using OPU-IMV and OPU-IVFB media were (13.2 ± 2.4) and (15.5 ± 0.9), respectively. Post-fertilisation, cleavage rate attained in OPU-IMV media was 51.9 ± 6.3% compared with 56.3 ± 2.6% cleavage rate in OPU-IVFB media. The mean blastocyst rate (23.5 ± 5.2%) and mean embryo/OPU (3.6 ± 1.1) in OPU-IMV media were higher than the blastocyst rate (19.2 ± 1.5%) and mean embryos/OPU (3.1 ± 0.3) in OPU-IVFB media. For any parameter, there were no statistically significant differences between the media groups. The findings suggest suitability of the OPU-IMV media for ovum pickup purposes, thus providing a cheaper alternative.