Scientific Opinion on Risk of transmission of TSEs via semen and embryo transfer in small ruminants (sheep and goats)

Transmissible Spongiform Encephalopathies (TSEs), small ruminants, semen, embryo transfer, transmission risk
First published in the EFSA Journal
6 January 2010
10 December 2009
Scientific Opinion


An assessment of the risk of transmission of Transmissible Spongiform Encephalopathies (TSEs) via semen and embryo transfer in small ruminants (sheep and goats) was performed. The TSE agents considered were Classical scrapie, Atypical scrapie and Bovine Spongiform Encephalopathy (BSE). Because of the lack of specific data for goats the assessment was carried out mainly using data obtained in sheep and, because of the similarities of TSE pathogenesis between sheep and goats, the assessment was also considered to be valid in goats. According to the data currently available, the risk of TSE transmission associated with semen and embryos collected from Classical Scrapie incubating sheep and goats ranges from negligible to low but the data are insufficient to conclude that such a risk is negligible. Because of the similarities between Classical scrapie and BSE pathogenesis in small ruminants, this statement is also to be considered valid for BSE. The lack of knowledge of the pathogenesis and anatomical distribution of the Atypical scrapie agent within affected animals hampers the possibility to provide an assessment of its transmission risk via semen or embryos. Due to the use of animal-derived hormones and surgical devices for artificial insemination and embryo transfer procedures there is an inherent but unquantifiable risk of iatrogenic TSE transmission associated with these practices.

Panel members at the time of adoption

Olivier Andreoletti, Herbert Budka, Sava Buncic, John D Collins, John Griffin, Tine Hald, Arie Hendrik Havelaar, James Hope, Günter Klein, James McLauchlin, Winy Messens, Christine Müller-Graf, Christophe Nguyen-The, Birgit Noerrung, Luisa Peixe, Miguel Prieto Maradona, Antonia Ricci, John Sofos, John Threlfall, Ivar Vågsholm, Emmanuel Vanopdenbosch
Panel on Biological Hazards
biohaz [at]
EFSA Journal 2010; 8(1):1429
Question Number
On request from
European Commission