What is cloning?
Cloning is an assisted reproductive technology that allows livestock breeders and others to create identical twins of their best animals. This breeding technique does not change the genetic make-up of the animal. The most common procedure 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. See cloning process.
How does cloning affect the DNA of animals?
Cloning does not change DNA and clones are not genetically modified organisms (GMO's). It is simply assisted reproduction.
How does cloning relate to other reproductive technologies?
Livestock cloning is the most recent evolution of selective breeding in animal
husbandry, which dates back to the dawn of time. Arab sheikhs first used artificial
insemination in horses as early as the 14th century. In the last fifty years,
techniques such as embryo transfer, in vitro fertilization, embryo splitting,
and blastomere transfer have become commonplace - providing farmers and ranchers
powerful tools for breeding their best animals. Cloning accelerates the birth of the best possible stock
by allowing farmers to be
certain of the
make-up of a particular animal. See timeline.
Is it safe to use clones in the food supply?
The U.S. Food and Drug Administration analyzed more than 100 scientific studies on cloning, encompassing years of safety data and several generations and large families of livestock. The FDA concluded: "The current weight of evidence suggests that there are no biological reasons to indicate that consumption of edible products from the clones of cattle, pigs, sheep or goats poses a greater risk than consumption of those products from their non-clone counterparts." See FDA's draft risk assessment.
The National Academy of Sciences (NAS) also scrutinized numerous studies, publishing in-depth reviews in 2002 and 2004. The NAS concluded that "there is no scientific evidence that cloning is associated with any unintended compositional change that results in an unintended health consequence in humans" and pointed out that consumers would get better food because clones have "increased genetic merit for increased food production, disease resistance and reproductive efficiency". See NAS Reviews.
Will we eat cloned animals?
Cloning will be used for breeding. These animals are very costly and will
represent the most valuable breeding stock; consumers are unlikely to
eat a cloned animal. They will eat food from animals that are the offspring
Does cloning make animals suffer?
The FDA has concluded that cloning 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. Because breeding the best possible stock improves the over-all
health and disease resistance
suffering over time.
Are cloned animals healthy?
A National Academy of Sciences review found that "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." See NAS Reviews.
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. These continuing improvements have reduced health problems seen in early reports to rates approaching those of other reproductive technologies.
How does the neonatal mortality rate of cloned animals compare to other animals?
Any animal conceived through an assisted reproductive technique has a 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.
Is there a risk of Large Offspring Syndrome (LOS) among cloned animals?
LOS occurs naturally in cattle. It is seen at higher rates with 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.
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.