The Ovum Pick Up technique consists in the transvaginal removal of the oocytes by aspiration of the ovarian follicles with the aid of an ultrasound probe. This procedure is absolutely harmless to the donor, the time taken for the collection is 15-20 minutes during which the donor is contained in a cattle crush.
The oocytes collected are selected in the laboratory and transferred to an incubator in a suitable culture medium to complete the maturation phase. On the day following retrieval, the oocytes are fertilized in vitro with the seed of the chosen bull and kept in incubator for about a week until the stage of embryos suitable for transfer to receiving cows or freezing is reached.
- Egg retrieval can be repeated many times twice a week;
- Each group of oocytes taken can be fertilized with the seed of a different reproducer. Therefore it is possible to obtain embryo groups with different paternity from the same donor in a very short time, on average 1-2 embryos for picking up from the heifers and 3-4 from the cows;
- Ovum Pick Up does not require any preventive hormonal treatment and does not interfere with the normal physiology of the donor;
- Ovum Pick Up embryos can be produced by donors of any age, even during lactation and in the first 3 months of pregnancy without the possible side effects of superovulation: infertility, ovarian cysts, mastitis, traumas related to behavioral changes induced by superdosing hormones, loss of time and milk production;
- For certain donors suffering from long-standing sterility, the Ovum Pick Up can even exert a therapeutic effect by removing the cystic formations that are often present on the ovaries of these animals, also as a consequence of repeated superovulations; in many cases it is possible to impregnate the subject at the end of the sampling cycles;
- All donors return to estrus 7-10 days after the last withdrawal and can be immediately fertilized. On request, the embryos produced can be sexed and the owner can selectively withdraw the embryos of the desired sex (see embryo sexing).
Over 2 and a half million embryos have been produced and transferred over the past 10 years and their number is growing steadily. The application of the Ovum Pick Up technique and the production of bovine embryos in vitro are growing rapidly worldwide: from 30,000 embryos transferred in 2000 to over 450,000 in 2016. The table on the side shows the data on the number of bovine embryos transferred worldwide *. It is noted that the number of embryos produced with superovulation (blue line) and transferred in 2000 (about 520,000) gradually increased until 2006 and then decreased and returned to about the same level in 2009 and then oscillated to stabilize around half a million in 2015 and 2016. In contrast, embryos produced in vitro (red line) and transferred have increased significantly since 2000, approaching the number of embryos produced in vivo in 2016. This world statistics confirms the growing diffusion of in vitro technologies and their increasingly important role in breeding programs and in the diffusion of bovine races in the world.
** Data from the International Society of Embryo Technologies. December 2017 Newsletter, www.iets.org
The Ovum Pick Up service is active at the Cremona office. Subject to agreements, the service can also be carried out at the client site.
All Avantea embryos are in possession of the health requirements for marketing both in Italy and abroad as required by Directive 556/89 / EEC and subsequent amendments.
Embryo sexing is based on the chromosomal difference that exists between embryos of the two sexes, i.e. the presence or absence of the Y chromosome (male embryos are carriers of the Y chromosome, which is absent in female embryos). To highlight this difference, biopsy is used, i.e. the removal of some cells of the embryo using a micro blade, in order to obtain a DNA sample to be analysed (Fig. 1). This DNA is multiplied through a procedure called PCR (Polymerase Chain Reaction) which can help to highlight the presence or absence of the Y male chromosome. Together with the Y-chromosome signal, a control signal is also obtained for all the samples analysed independently of the sex. The signals obtained are visible in the form of fluorescent bands after electrophoresis of DNA samples in an agarose gel (Fig. 2). The interpretation of the result is very simple: the presence of a single band indicates that the biopsy was taken from a female embryo while the presence of two bands indicates that the biopsy was taken from a male embryo. The diagnosis of sex is 97% accurate. Sexed embryos can be frozen exactly like non-sexed embryos.
Fig. 1: Sequence of embryonic biopsy. With the aid of a micro blade, a small group of cells is separated from the rest of the embryo. The DNA contained in these cells is used for the determination of sex.
Fig. 2: Electrophoresis of embryonal DNA samples in agarose gel. The samples showing two bands correspond to biopsies taken from male embryos; the samples in which only one band is visible correspond to biopsies taken from female embryos.
All cows are suitable donors for the Ovum Pick Up technique starting from the eighth-ninth month old heifers to cows, both in dry and lactation. In addition, pregnant cows up to the third month of pregnancy can also be ovum donors without any risk for the current pregnancy.
No, no hormonal treatment is necessary. In fact, this technique does not interfere with normal fertility and milk production.
Yes, successfully because in vitro fertilization requires a much lower number of spermatozoa than that required for normal artificial fertilization. Therefore, even small quantities of vital seed, as can happen in the case of sexed semen, are sufficient to obtain embryos.
The procedure can be repeated twice a week for several weeks without side effects and without interfering with the fertility of the donors.
Yes, for each Ovum Pick Up sample, usually only one bull is used, but in cases where the number of oocytes collected is very high (over 30 oocytes) it is advisable to use two bulls if more couplings are required.
After about two weeks.
Yes, the embryos produced with Ovum Pick Up can be frozen like those produced with superovulation.
This depends primarily on the age of the donors: the heifers produce 2-3 embryos per collection, the cows 4-6 per collection.
The main advantages are: a) in a short time it is possible to produce embryos with different couplings by choosing a different torus for each oocyte collection; b) no hormonal treatments are necessary; c) there is no interference with the milk production since the lactating donor has no production loss and no effect on the breast or on the pregnancy.