Production in vitro of bovine embryos

Source: INTA EEA Balcarce

"With a dose of semen of high value we can produce between 20 and 30 calves. The in-vitro production technique of bovine embryos is under conditions of being implemented technically and commercially, in the laboratories of the INTA EEA Balcarce that have been reconditioned to be adjusted to the international norms of production of embryos", Dr. Ricardo Alberio explained to, investigator and coordinator of the Reproduction Biotechnology Group of this Unit.

"It is a technique in which its bigger benefit is found in the saving of semen of high value and in the comparative advantages of its use in programs of genetics improvement. In the country only two or three laboratories are carrying it out successfully."

Embryos that are produced in-vitro, how are they obtained? Doctor Alberio indicates that "they are achieved starting from ova (ovocitos) recovered from ovaries that can either come from animals that are going to the slaughterhouse or from live animals (castrated animals and ovarian punction). The ova is transferred to the laboratory, fertilized and cultivated in a "stove" during seven days. Concluded this period, the produced embryos are under conditions of being transferred to a receptive cow, or frozen to be transferred in the appropriate moment."

It is a technique of recent development whose use has begun to spread starting from the 90's and in wider form in the last 3 years.

In animal production it has different types of applications, "from those dedicated to being use in programs of genetic improvement, which is where more impact it has had, to other uses that are related to the increase of the individual efficiency, as in the case of its use for the production of twins in bovine", the specialist explains.

As for the production of twins in bovine, it is achieved when, seven days later, a second embryo in-vitro is transferred to the inseminated cows. You can also arrive to the same condition by transferring two embryos to cows that, in the moment of the zeal, service was not given. This way there will be a proportion of those animals that will become pregnant and give birth to twins.

What differences are there among the embryos produced by the in-vitro technique, and the ones produced by "super-ovulation"?, was asked to doctor Alberio: "Habitually we are accustomed to the transfer of embryos coming from cows that are treated with certain hormones to increase the production of ova. Once fertilized, the development of the embryos takes place for a while (7 days of life of the embryo) until the moment that they are collected from the cows called donors and they are transferred to cows that are called receptors."

In the case of embryos that are produced in-vitro, starts from animals that have not had any treatment at all. Their ova (obtained as it was mentioned before) are taken to the laboratory, fertilized and cultivated, and the embryos are ready for their use.

Apart from this, there are some differences in some aspects of their vitality and their resistance to freezing. From a practical point, the most important difference is in the cost: an embryo produced in-vitro costs around 10 times less than a embryo produced "in-live" and to produce 100 of these embryos, a single dose of semen is enough, as opposed to two doses of semen needed to produce 4 to 6 embryos when using the "super-ovulation" technique.

In synthesis, the first advantage is the possibility to recover the characteristics of animals that have to be sacrificed for different reasons but, however, they have a high genetic value. Their ovaries can be recovered and starting from there, obtained the supplementary breeding from an animal that is already dead.

The second advantage is being able to produce calves starting from live cows in more quantity that those that are obtained with the "super-ovulation" treatments.

The third advantage is increasing the possibility of use for semen of high value.

In the country, this technique is being carried out in two or three laboratories, although from a commercial point of view, only that of the INTA EEA Balcarce is being implemented. "At the present time we have inaugurated the remodeling of our embryos production laboratories which does not only assure their qualitative aspect in relation to the international norms but rather it allows a production in scale impossible to carry out under the previous conditions", doctor Alberio assures.