Frequently Asked Questions about Animal Cloning

What is animal cloning?
Cloning is an assisted reproductive technology that allows livestock breeders to create identical twins of their best animals.  This breeding technique does not change the genetic makeup of the animal.  The most common procedure used today is known as somatic cell nuclear transfer (SCNT), which makes it possible to produce many animals from a single donor.  SCNT involves transferring the genetic information from one animal into an empty oocyte, or egg.  This process results in an embryo, which is implanted into a surrogate mother who carries the pregnancy to term.

How does cloning affect the DNA of animals?
Cloning does not change DNA, and clones are not genetically engineered animals.  It is simply assisted reproduction, similar to embryo transfer, artificial insemination, or in vitro fertilization.

Is animal cloning a new technology?
Animal cloning has been rigorously studied for decades, since the earliest research on embryo splitting in the late seventies and early eighties.  The U.S. Food and Drug Administration has analyzed numerous scientific studies on the subject, conducted over 30 years and encompassing several generations and large families of livestock. 

Cloning and Animal Health

Does cloning cause animal suffering?
Cloning enhances animal wellbeing, and is no more invasive than other accepted forms of assisted reproduction such as in vitro fertilization. In fact, clones are the “rock stars” of the barnyard, and therefore are treated like royalty.  Breeding the best possible stock improves the over-all health and disease resistance of animal populations.  Additionally, because these breeding techniques can improve the over-all health and disease resistance of an animal, cloning will greatly reduce animal suffering.

Are animal clones healthy?
Decades of research has shown that cloned animals are as healthy as conventional animals.  A National Academy of Sciences (NAS) review found “the health and well being of somatic cell clones approximated those of normal individuals as they advance into the juvenile stage. Somatic cell cloned cattle reportedly were physiologically, immunologically, and behaviorally normal.” 

How does the neonatal mortality rate of animal clones compare to other animals?
Any animal conceived through any assisted reproductive technique — AI, embryo transfer, etc. — has a slightly higher risk of neonatal death.  In the hands of skilled scientists, the neonatal death rate of cloned animals approaches that of animals produced by in vitro fertilization. Within hours or days of birth, there are no health differences between clones and non-clones, according to an NAS review panel.  A common misconception is that clones suffer a higher deformity rate than other animals.  Only the placentas of clones show any difference from animals born conventionally.  In fact, these placental problems occur at similar rates in other assisted breeding techniques, such as in vitro fertilization and embryo transfer.  Scientists are working to reduce the impact of placental effects on embryo implantation for a successful pregnancy.

Don’t clones suffer a higher rate of deformities than other animals?
No.  Only placentas of clones show any difference from animals born the conventional way.  However, these placental problems occur at similar rates in fetuses produced through other assisted breeding techniques, such as in vitro fertilization and embryo transfer.

Is there a risk of Large Offspring Syndrome (LOS) among animal clones?
LOS occurs naturally in cattle.  It is seen at higher rates with any assisted reproductive technologies and is not a problem caused specifically by cloning.

Are embryos lost while creating clones?
Embryos are lost in any form of reproduction — including sexual reproduction. In the hands of skilled practitioners, cloning success rates approach other forms of assisted reproduction.

How has the cloning process evolved since Dolly's birth?
Every step of the cloning procedure has improved in the decade since Dolly’s birth.  Continuing improvements have reduced health problems seen in early reports to rates approaching those of other reproductive technologies.

Did cloning affect Dolly's health and lead to her premature death?
Dolly died of cancer resulting from viral pneumonia.  This disease outbreak killed many other sheep the same year she died and affected many animals housed in the same barn.  Although it was widely reported in the press that Dolly suffered from arthritis and may have aged prematurely, there is no evidence in the scientific literature that this was true for Dolly or other clones.

Is cloning ethical?
While it is up to each individual to determine their viewpoint on different technologies, the major world religions do not have an issue with livestock cloning.  The Catholic Church, in its “Reflections on Cloning,” says “there is a place for research, including cloning, in the vegetable and animal kingdoms.”  On the whole, leading Muslim and Jewish thinkers also agree that cloning is acceptable to meet standards of kosher and halal.

Animal Clones and Their Food Products