and 2% of dairy cattle produced through natural matings or AI die between birth and 6 months of age (Table V-1, FDA 2006). Thus SCNT clones death rate from birth to 6 months of age is some 10 times to 16 times higher than that of naturally produced dairy cows and beef cows, respectively.
SCNT cloning also can produce quite a range of deformities and at a higher rate than from regular reproduction. Some of the deformities found in the various studies cattle include limb deformities, abnormal or degenerating kidneys, digestive tract problems, chronic heart failure, degenerative nephrosis, musculoskeletal abnormalities and cryptorchidism.
For pigs, there are very few data on mortalities and deformities. One Connecticut study found that of 4 pig clones born, one died within a week and the other three died unexpectedly at 6 months (Lee et al. 2003). One deformity that has been seen is anal atresia, which is lack of an anal opening. Anal atresia occurs naturally in pigs at a rate of
% - 1.0% (Wiedemann et al. 2005). A New Zealand study found that 1 of 28 (or
%) pig clones born had anal atresia, which is 3.6 times to 36 times higher than the rate
that occurs naturally.
There are also interesting differences in the survival of progeny of clones compared to progeny of non-clone comparators between the breeds (Table F-11 in FDA, 2006). The percentage of mummified pigs (dead, dessicated fetuses) was 3.3, 2.8, 1.7, and 0 percent for the progeny of Hamline comparators, Hamline clones, Duroc comparators, and Duroc clones, respectively. In both breeds of pigs (Hamline and Duroc), the percentage of mummified pigs was larger for the non-clone pregnancies compared to the clone pregnancies and all but the Duroc clones had rates of mummified pigs greater than the national average of 0.2 percent. FDA had no explanation for these results.
More interestingly, a significant number of pigs died around the time of birth, with the rates being clearly higher for the clone offspring compared to the non-clone comparator offspring for both breeds, although the effect was stronger for Durocs than Hamlines. For Hamlines, the pre-weaning death rate was 21 percent higher for progeny of clones compared to progeny of non-clone comparators (22.5% and 18.6%, respectively). For Durocs, the pre-weaning death rate was almost 85 percent higher for progeny of clones compared to progeny of non-clone comparators (31.4% and 17.0%, respectively), with almost one-third of the progeny of Duroc clones dying shortly after birth. Although the difference in pre-weaning death rates is more pronounced for progeny of Duroc clones, FDA tries to explain away this difference by arguing for the exclusion of a litter of 13 Duroc clone progeny and their mother that died shortly after birth due to the stress from high temperature and humidity. FDA notes, however, the other female pigs were also heat-stressed, but didn’t remove data from those pigs. Again, FDA interprets data in such a way to minimize the potential effect of cloning. Even if one accepts FDA’s argument and removes the data on these 13 progeny of a Duroc clone, the pre-weaning death rates are still over 21% higher for the progeny of clones compared to progeny of non-clone comparators for both pig breeds (Duroc and Hamline). Yet,