Abstract
The European Food Safety Authority (EFSA) received in December 2011, a request from the European Commission for an update on the possible scientific developments for cloning of farmed animals for food production purposes. The present Statement follows the EFSA 2009 and 2010 Statements and the EFSA 2008 Scientific Opinion, and is based on peer reviewed scientific literature published since the EFSA 2010 Statement, information made available to EFSA following a call for data, and discussions with experts in the field of animal cloning. As reported before, Somatic Cell Nuclear Transfer (SCNT) can produce healthy clones, but a portion of the animal clones suffered from developmental abnormalities likely due to epigenetic dysregulation (incomplete nuclear programming) and died at various stages of development. For some of the live animal clones, in particular calves and piglets, health and welfare were compromised specifically within the perinatal and juvenile period. Also some of the surrogate dams were affected due to abnormal pregnancies. Food products from healthy clones, i.e. meat or milk, did not differ from products from healthy conventionally bred animals. The offspring of clones and their food products showed no differences with conventional offspring or products. Data on clones of farmed species for food production other than cattle and pigs have remained limited and do not allow for the assessment of food safety or animal health and welfare aspects. The cloning efficiency, defined as the number of live offspring as a proportion of the number of transferred embryos, remained about 6–15 % for cattle and about 6 % for pigs. When compared with in vitro fertilisation (IVF), for which the background percentage of live offspring per transferred embryo is 45–60%, the efficiency of cattle SCNT relative to IVF is 13–25%. To overcome the relatively low cloning efficiency researchers continue to amend cloning procedures, with limited improvements shown by some researchers.