31. Since Dolly was derived from the adult nucleus of a 6-year old sheep, it remains to be seen if she has a shorter lifespan than normal, or will indeed develop other abnormalities in due course. Thus the long-term effects of the technology on animals such as those produced at Roslin are unknown. No abnormalities have been experienced so far but these animals are now only two to three years old. It has also been recently announced that Dolly has produced an apparently normal lamb, named Bonnie, which gives some assurance of the normality of her DNA. Nevertheless, the effect on long-term survival and morbidity of inserting aged DNA into oocytes is a matter for further research and better understanding.
32. Research into the long-term effects of nuclear transfer of aged DNA is required before the technique should be considered in agricultural practice.
33. Until the problems of oversized offspring, embryonic and fetal losses and birth abnormalities, and the possibility of problems associated with aged DNA, have been satisfactorily resolved, there should be a moratorium on the use of cloning by nuclear transfer in commercial agricultural practice.