Science in Society Archive

Is FDA Promoting or Regulating Cloned Meat and Milk?

Dr. Mae-Wan Ho and Prof. Joe Cummins find cloned meat and milk unethical and unsafe.

This article has been submitted to the FDA. Please circulate widely to your elected representatives

Massive public opposition

US Food and Drug Administration (FDA) is about to approve cloned meat and milk for the market. But a large coalition of civil society organizations is opposing the decision on both safety and ethical grounds [1]. The coalition is led by the Center for Food Safety based in Washington DC, and includes the Humane Society with nearly 10 million members, and the Consumer Federation of America with membership of more than 50 million.

A recent poll commissioned by the International Food Information Council (a non-profit organization supported by the food, beverage and agricultural industries) found nearly 60 percent of respondents would not touch products from cloned animals with only 9 percent “very likely” to buy them. This compares with 40 percent who would not buy genetically modified animal products.

Europe's dilemma

The European Commission's directorate general for health and consumer protection received a report from the project “Cloning in Public” in December 2006, outlining the regulatory dilemma facing the European Union. The leader of the project, Peter Sandøe, a professor of bioethics at the Royal Veterinary and Agricultural University in Copenhagen, said Europe can either stay put or start building cloning regulations sensitive to ethical concerns now, depending on whether cloning will really take off. If agricultural animal cloning turns out to be mostly hype, as many in Europe suspect, Europe's current legislations will mostly suffice. If not, the EU would be unable to legally block imports of animal clones, despite opposition from consumer groups. Building new cloning legislation is an agonizing long draw-out process, and ethics-based regulation would be hard to enforce, and all that could turn out to be a huge waste of time and effort if animal cloning will not take off after all.

Not surprisingly, the European Commission has decided to stay put. Philip Tod, spokesperson for Markos Kyprianou, EU commissioner for health and consumer protection said EU legislation in place for animal breeding, novel foods and animal welfare is considered sufficient to cover any cloning-related issues that are likely to arise. The Commission is continually monitoring the developments in cloning and the international situation, and will not hesitate to take the necessary steps “if there is deemed to be a need for further scientific assessment or risk management, or a review of the legislation to reflect new development.”

Daughter of cloned cow born in UK

But events may have overtaken this decision. In January 2007, UK newspaper Daily Mail reported that a daughter of a cow cloned in the US was born on a farm in Shropshire in Britain, the product of frozen embryos imported from the US and implanted into a surrogate mother [2]. This has triggered EU watchdogs to investigate the safety of food from cloned animals and their offspring. Conservative MEP and agriculture spokesperson in the European Parliament Neil Parish said, “We have no shortage of high-producing excellent dairy cows in the UK, so why are we risking a collapse in consumer confidence by importing the offspring of cloned cows?”

It seems that although the existing food safety system in Britain and Europe requires an assessment of meat and milk from cloned animals, a loophole remains so that food derived from the offspring of clones does not. Britain's Food Standards Agency raised the issue at a meeting of the EU's Novel Foods Working Group.

Misleading ‘risk assessment' by FDA and cloning companies

In preparation for FDA's approval of cloned animal products, the agency published a ‘commentary' in the January 2007 issue of Nature biotechnology [3] supported by a ‘perspective' piece on risk assessment, co-authored by scientists from at least two cloning companies [4]. Both papers put the same misleading positive gloss on cloned animals. The FDA paper explains why cloned meat and milk are as safe as the conventional products, because “there are no unique risks associated with animal cloning,” while the risk assessment commentary cites the FDA paper in agreement. Neither paper considers ethics or animal welfare.

Both papers present somatic cell nuclear transfer cloning (SCNT) reassuringly as the latest development in a “continuum” of artificial insemination, multiple ovulation/embryo transfer, in vitro fertilization, embryo cryopreservation, cloning by embryo splitting, and since the 1980s, by embryonic cell nuclear transfer (ECNT).

First of all, it is highly misleading to pretend that clones obtained by nuclear transfer are the same as clones obtained by embryo splitting. The latter is typically done at the 2-4 cell stage, and is not so different from the twins or multiplets that happen naturally from time to time.

Nuclear transfer cloning involves introducing the nuclei of embryonic cells (in ECNT) or adult somatic cells (in SCNT) into unfertilised eggs that has had the egg nucleus removed. The reconstituted eggs are then activated to develop, and the resultant embryos are implanted into surrogate mothers hormonally synchronized to receive them. Nuclear transfer cloning, especially SCNT results in extremely high failure rates from deaths and gross abnormalities, so much so that scientists speak of a “cloning syndrome” that arises from errors in epigenetic programming of the cell nucleus [5, 6]. The individual symptom may not be unique, but the combination and the high incidences of the symptoms certainly constitute a unique syndrome. It inflicts massive deaths, suffering and distress, not only to the cloned foetuses and the calves throughout gestation, at and after birth, but also to the surrogate mothers [7]. Surrogate mothers frequently die from difficult delivery unless medical intervention is given, and their health is seriously compromised by gross malformations of the foetuses.

There is also a big difference between ECNT in the 1980s and 1990s and SCNT, which began with Dolly the sheep cloned in 1996, and has widely supplanted ECNT since. ECNT before 1996 involved transferring the nuclei of embryos at a few cells stage (8-32 cells), and there is a limit to the number that can be cloned from a single individual embryo. In SCNT, there is no limit to the numbers of reconstituted eggs that can be created from a single individual adult, typically hundreds, just to get a few successful clones. This inevitably results in a great reduction of genetic diversity, which could make entire cloned herds susceptible to the same diseases.

The whole point of cloning from an adult individual is that it has proven ‘elite' qualities, whereas the qualities of embryos are completely unknown. So while the cloning umbrella covers both split embryos and ECNT, that's only regulatory camouflage intended to get SCNT approved with the more conventional methods.

The FDA paper explains how the agency had requested industry in 2001 to “voluntarily refrain from introducing food and feed from animal clones and their progeny into commerce” while FDA undertook a risk assessment of the safety of dairy and meat products derived from animals produced by somatic cell nuclear transfer (SCNT).

But according to the risk assessment perspective from industry [4], the public has already been consuming cloned meat and milk for years without their knowledge. Perhaps that too, is meant to be reassuring.

“Approximately 1,200-1,500 cows and bull were produced by ECNT in North American in the 1980s and 1990s.” Most of these cloned dairy and beef cattle produced for research or commerce “were used for human food consumption with no public knowledge or regulatory review.” They estimate that “more than 300 000 kg meat and more than 2 million litres of milk from cloned cattle have probably entered the food supply.”

They admit, however, that as these cloned animal products were mixed with non-cloned animal products, “minor problems would have gone undetected.” And as no data were collected on health-related issues after consumption of such meat or milk products, “any statement on effects is conjecture.” It should be emphasized that those cloned meat and milk entering the food chain in the 1980s and 1990s were predominantly from split embryos, and not from nuclear transfer cloning.

Admittedly, many deaths and gross abnormalities occur in animal cloning, but the companies claim that those clones born alive and survive the perinatal period are healthy [4]. To support their case, they tabulate nine studies, eight published elsewhere and one described in their paper, showing that the milk and meat products from clones are indistinguishable from controls, according to compositional studies on proteins, fats, somatic cell count, amino acid composition, vitamins, minerals etc, as recommended by the FDA [3].

Had the FDA recommended more discerning tests similar to those now routinely used in the laboratory for DNA, RNA, protein and metabolic profiling, large numbers of differences would have been detected, as SCNT clones are notorious for epigenetic errors that result in major changes in DNA markings, RNA and proteins expressed (see below), and it would be surprising if these did not result in metabolic differences.

The most substantial of the eight published studies came from the other regulatory agency, the USDA [8]. It looked at milk in 608 cloned cattle from conventional embryo splitting and 13 from ECNT, but none from SCNT. The second study involved the carcass of 8 ECNT cattle only; the third fed milk from an unknown number of SCNT cattle to rats; the fourth examined blood chemistry of 18 SCNT cattle. So, only three studies compared SCNT cattle carcass or milk with controls, and involved small numbers, from one to a maximum of twelve (total 18), the ages of which were not specified. One of the three studies also fed meat from one ECNT and one SCNT cattle to mice and rats. The additional study presented in the paper itself [4] included new data on blood chemistry and meat composition of 11 SCNT cloned cattle compared with the same number of controls, all older than 12 months.

By any standards, these data are grossly inadequate to establish the safety of cloned meat and milk or any other cloned animal products. They are also fundamentally flawed, as single parameters are compared, rather than an entire pattern, so when differences did occur between the cloned and non-cloned siblings, they were dismissed by the comment that the values were within the normal range typical of the breed or species.

The authors try to gloss over the findings that apart from high perinatal death rates (which would be even worse without medical interventions), many die before 6 months of age, and those that survive are fragile throughout life. Others have reported increased annual death rates due to euthanasia of cloned cattle with musculoskeletal abnormalities [5, 6]. In fact, the “cloning syndrome” is regarded as a continuum occurring throughout the life of the clone, in that “lethality or abnormal phenotypes that affect health or production may occur at any phase of development possibly dependent upon the degree of dysregulation of key genes. Even apparently normal clones may have abnormal regulation of many genes that are too subtle to result in an obvious phenotype.”

The FDA, however, helpfully noted that those cloned cattle that had to be put down are “otherwise healthy.”

The real story about cloning

At issue is SCNT, the procedure pioneered in creating Dolly the cloned sheep in 1996 [9] Death Sentence on Cloning , SiS 19). Cloning from the genetic material of an adult animal means that all the genetic ‘elite' qualities of the animal are proven, so the clones in theory will reproduce those ‘elite' qualities. More to the point, it allowed the duplication of genetically modified (GM) animals without the normal reproduction process, as GM animals tend to be either sterile or to lose their transgenes or transgene expression in subsequent generations. Dolly was a rehearsal for the cloning of an ‘elite' herd of transgenic animals producing valuable pharmaceuticals in their milk. That turned out to be a pipedream. Cloning does not faithfully reproduce the qualities of the adult, elite or otherwise.

The success rate of SCNT is extremely low, and remains so to this day, between 0 and 5 percent across the species: sheep, cattle mouse, pig, goat, rabbit, cat, not withstanding. Here is how one reviewer among many, Jonathan Hill at the College of Veterinary Medicine, Cornell University, New York described it when he was opposing human reproductive cloning [10].

“In each of the species where somatic cell cloning has been successful, it has also been very inefficient. Early first trimester pregnancy rates are less than ½ that normally expected. Immediately following initial positive diagnosis of pregnancy, extraordinarily high rates of embryonic loss occur, where up to 80% of pregnancies miscarry by the second semester. In late gestation, placental and fetal abnormalities occur at a much higher than normal rate, and finally lowered viability at birth is common.”

So hundreds of reconstituted eggs have to be created to get dozens of embryos good enough to be implanted into surrogate mothers just to end up with a few clones born live.

Those few clones that survive after birth are by no means healthy: “Postnatal viability is markedly lower for many cloned animals….Neonatal viability has been shown to be compromised due to pulmonary immaturity.”

The remaining that seem apparently healthy are not without problems, for “closer investigations have revealed that even some of these apparently normal animals are subtly different from one another and from the naturally produced population… What is of significant concern is that placental development and the intrauterine environment for many clones is suboptimal and this alone may impact on their health in later life.”

This was borne out by numerous laboratories involved in cloning. In one experiment [5], 988 SCNT embryos were transferred into cows resulting in 133 calves delivered at term, but only 67 percent survived to weaning at 3 months of age, with an average annual death rate thereafter of more than 8 percent. The offspring of SCNT clones fare better, though they have not been subjected to more discerning tests either.

Dolly had to be put down prematurely at age six on account of severe illnesses, and the company PPL therapeutics that helped to create Dolly failed to find a backer for its GM alpha-1 anti-trypsin produced in cloned transgenic sheep's milk, and had to slaughter its flock of 3 000 transgenic sheep in 2003 [11] ( Animal Pharm Folds , SiS 19). Thus, SCNT has proven neither technically successful nor economically viable.

Many, including Ian Wilmut, the creator of Dolly, saw that as the end of SCNT cloning for producing animals, and have since concentrated efforts into creating embryonic stem cells for tissue replacement. But that too is misguided and ethically unjustified as many clinical successes in tissue replacement have been documented using the patient's own adult stem cells while embryonic stem cells have yet to prove themselves in a single clinical application so far [12] ( No Case for Embryonic Stem Cells Research , SiS 25).

The major problem with SCNT clones and with embryonic stem cells made by SCNT cloning is the large numbers of genome-wide epigenetic errors in gene expression associated with the nuclear transfer process, resulting in the high failure rates of clones, and in the eyes of many scientists, precludes the safe use of SCNT-derived embryonic stem cells in tissue replacement [13].

Microarray analysis of more than 10 000 gene in clones found that about 4 percent of the genes in the placenta are different from normal, with a smaller number of genes also affected in the liver [14].

FDA paves the way for cloned transgenic animals

Indeed, the FDA does not see whole herd of cloned animals, and it seems likely that the cloning process is intended at least in part to support the creation of transgenic herds. FDA states [3]: “Because of the cost of clones and the high efficiency of sexual reproduction based on selection of traits found in male cattle and swine, herds of dairy or swine clones are not expected in the immediate future. Most of the food produced from the cloning process will be meat and milk derived from the sexually produced offspring of clones. The producing of milk by clones may be considered as a by product of cloning cows (or other dairy animals) for breeding purposes. Clones may also enter the food supply as meat when they age beyond reproductive utility, when they are injured or simply for financial reasons.”

FDA admits epigenetic errors as a source of hazards [3]: “the low success rates of SCNT, the perinatal difficulties observed in some newborn clones and occasional examples of altered metabolic pathways in very young animals” However, it reassures us that because grossly affected animal would either die, fail to reproduce or fail a government examination and meat inspection, their meat or milk would not enter the human good supply, and the only remaining food consumption hazards arising in clones would be those reprogramming errors that allow the animals to develop with apparently normal functions, but with subclinical physiological defects.

It is clear that FDA is intending by products from experimental animals to enter the human food chain. There is no guarantee that sick or dead clones, or failed laboratory experiments will not enter the food chain as meat or sausage, for example. There have been many breaches of the regulation regarding transgenic meat products, with transgenic pigs ending up in sausages in 2003 [15], and it would surprising if these breaches will not occur in the case of cloned meat products.

The sexually derived progeny of clones are thought to be exempt from propagating epigenetic derived defect, but as mentioned earlier, these have not been subjected to any scrutiny beyond the observation that they seem healthy.

FDA has enunciated two principles of risk assessment with regard to cloned animal product [4]: the Critical Biological Systems Approach, based on the hypothesis that a healthy animal is likely to produce safe food products, even if it needs some help during development; and the Compositional Analysis Method, based on the hypothesis that food products from healthy animals clones and their progeny that do not differ materially from food from conventional animals are as safe to eat as their conventional counterparts. Many will not find this reassuring. The FDA has put such a positive spin on cloned animal products that it is easy to mistake them for the promoters instead of regulators.

The public are right to oppose cloned animal products. Somatic cell nuclear cloning is unacceptable on both ethical and safety grounds, and it will pave the way to creating herds of transgenic animals that are likely to be contaminated by potent vaccines, immune regulators and growth hormones as well as nucleic acids, viruses and bacteria that can create pathogens and trigger cancer [16] ( GM Food Animals Coming , SiS 32).


  1. “FDA's cloning report bypasses ethics, exposes European dilemma”, Peter Vermij, News, Nature Biotechnology 2007, 25, 7-8.
  2. “EU puts its food police on the case of the cloned calf”, Daily Mail 15 January 2007, ( )
  3. Yang X, Tian XC, Kubota C, Page R, Xu J, Cibelli J and Seide Jr.G. Risk assessment of meat and milk from cloned animals. Perspective, Nature biotechnology 2007, 25, 77-83.
  4. Rudenko L, Matheson JC and Sundlof SF. Animal cloning and the FDA- the risk assessment paradigm under public scrutiny. Commentary, Nature biotechnology 2007, 25, 39-43.
  5. Wells DN, Forsyth JT, McMillan V and Obeck B. The health of somatic cell cloned cattle and their offspring. Cloning Stem Cells 2004, 6, 101-10.
  6. Wells DN. Animal cloning: problems and prospects. Rev Sci Tech 2005, 24, 251-4.
  7. “Cloned animals a gallery of horrors”, i-sis news13/14 , 12, 2002.
  8. Norman HD and Walsh MK. Performance of dairy cattle clones and evaluation of their milk composition. Cloning Stem Cells 2004, 6, 157–164
  9. Ho MW and Cummins J. Death sentence on cloning. Science in Society 19 , 46-47.
  10. Hill JR. Abnormal in utero development of cloned animals: implications for human cloning. Commentary. Differentiation 2002, 69, 174-8. Depart of Clinical Sciences College of Veterinary Medicine, Cornell University, New York.
  11. “Animal pharm folds”, Mae-Wan Ho, Science in Society 19 , 43, 2003.
  12. Ho MW. No case for embryonic stem cells cloning. Science in Society 25 , 34-37, 2005.
  13. Armstrong L, Lako M, Dean W and Stojkovic M. Epigenetic modification is central to genome reprogramming in somatic cell nuclear transfer. Stem Cells 2006, 24, 805-14.
  14. Humphreys D, Eggan K, Akutsu H, Friedman A, Hochedliner D, Yanagimachi R, Lander ES, Tolub TR and Janeisch R. Abnormal gene expression in cloned mice derived from embryonic stem cell and cumulus cell nuclei. PNAS 2002, 99 (20), 12889-94.
  15. “Research piglets sold as food hard to find”, Elizabeth Weise, USA Today, 2 July 2003,
  16. Cummins J and Ho MW. GM food animals coming. Science in Society 32 , 24-29, 2006.

Article first published 26/01/07

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