Biosecurity –its added value to Embryo Transfer

Background: Both in vivo derived (IVD) and in vitro produced (IVP) embryos in cattle have been transferred worldwide for many decades with great success. Among the many reasons for this to occur, one concerns the Biosecurity issues which if managed adequately may add a significant value to this Embryo Transfer (ET) technology. There are a number of conditions for this to be the case. Review: The present review emphasized the critical points all along the procedures which allow the practitioners to provide a high degree of safety to their operations because if not under strict care, pathogens mainly from the genital tract of the donors of embryos or of oocytes but not exclusively, may be associated to the embryos and hence contribute to spread diseases into the herds of the recipients. Sound scientific data have been elaborated by the researchers along the last decades which have been able to generate appropriate regulatory measures. Risks at stakes are here reported, both from in vivo collected or from in vitro produced embryos. They mainly concern various viruses and bacteria such as the Foot and Mouth disease virus or others and this review summarized the most relevant studies referring to them. We also described the sequences of events along the procedures that might contribute to such an association between the pathogens and the embryos. The knowledge of such sequences allowed the embryo transfer industry to adopt appropriate means to manage the risks and hence to mitigate almost to a negligible level such risks and hence providing the Biosecurity added value to this technology. Those means have been identified and assessed through an active participation of the International Embryo Transfer Society/ Health And Safety Advisory Committee (HASAC), then acting as an ad hoc committee to the World Animal Health Organization (OIE). The recent 4 edition of the IETS Manual (2009) provides an excellent document for the practitioner to proceed safely. We here summarized some of the most important steps and in particular the way the embryos should be handled once the in vivo derived embryos or the oocytes for in vitro produced embryos are collected. For the in vitro produced embryos, emphasis was here given on the collection of ovaries when this is to occur from abattoirs stressing the point that no animal should be present in the abattoir chain for depopulation reasons when ovaries are collected for IVP embryos. The close relationship between IETS and OIE has allowed the OIE to introduce those measures as recommendations into its Terrestrial Animal Health Code giving the international world, efficient and workable proven guidelines. The present review reported also on the basic principles to follow to give its full degree of Biosecurity. Those principles rely on the critical and ethical role of the embryo transfer or the embryo production teams under the leadership of one veterinarian. Conclusion: several decades of experience with close to 10 million of embryos transferred since the beginning of this century have demonstrated that providing that those rules are strictly followed, biosecurity is a real added value to these technologies.