The risk of small ruminant lentivirus (SRLV) transmission with reproductive biotechnologies: State-of-the-art review

Reproductive biotechnologies are essential to improve the gene pool in small ruminants. Although embryo transfer (ET) and artificial insemination (AI) greatly reduce the risk of pathogen transmission, few studies have been performed to quantify this risk. The aim of this review is to contribute to the elements needed to evaluate the risk of lentivirus transmission in small ruminants (SRLV) during ET, from embryos produced in vitro or in vivo, and with the use of the semen destined for AI. The purpose is to consider the genetic possibilities of producing uninfected embryos from infected females and males or bearers of the SRLV genome. We have reviewed various studies that evaluate the risk of SRLV transmission through genital tissues, fluids, cells, and flushing media from female and male animals. We have only included studies that apply the recommendations of the International Embryo Transfer Society, to obtain SRLV-free offspring from infected female animals using ET, and the justification for using healthy male animals, free from lentivirus, as semen donors for AI. As such, ET and AI will be used as routine reproductive techniques, with the application of the recommendations of the International Embryo Transfer Society and World Organization for Animal Health.