In vitro embryo production in the cow: An effective alternative to the conventional embryo production approach

Development of new technology related to in vitro embryo production has all owed for the commercial use of this method of reproduction. In the present work, we evaluate the efficiency of this technology compared with conventio nal embryo production based on results obtained with a standard procedure, including the sexing of embryos. The donor animals were mature nonlactating dairy cows (n=92) kept under a constant environment and feeding program in an ET center. Ultrasound guided transvaginal ovum pick-up following 48 h p re-treatment with FSH has been used for the IVF-IVC protocol. A total of 43 7 oocyte recovery sessions performed on 92 cows yielded 4145 oocytes, which were used in an IVF-IVC protocol. Using the conventional approach, 156 emb ryo collections on 49 cows yielded 1652 ova and embryos. All Quality 1 and 2 embryos were sexed by a PCR procedure, and embryos of the desired sex wer e transferred to synchronized recipients located at the center. The results obtained in the IVF protocol showed that 4 oocyte collections per cow perf ormed within 60 d, yielded 38 oocytes, which resulted in 18.8 viable embryo s, of which 7.05 were female. After transfer of the female embryos, an aver age of 3.8 recipients were pregnant at 60 d. One embryo collection under th e conventional approach yielded an average of 1.2 female pregnancies, which was confirmed during the same 60-d time period. These results indicate tha t IVF procedures can effectively replace conventional embryo production met hods when a predetermined number of pregnancies of known sex are needed wit hin a short period of time. (C) 1998 by Elsevier Science Inc.