A pioneer study has shown that meat and milk from cloned bulls and cows meet industry standards, and beef and milk from cloned cattle are safe for human consumption, researchers said on Monday.
The study, conducted by a team from the University of Connecticut and the Kagoshima Prefectural Cattle Breeding Development Institute in Japan, is published in the latest issue of the Proceedings of National Academy of Science. Examining specific proteins and nutrients in the milk and meat from cloned animals, it may eventually lead to regulatory approval of clone-derived food.
The researchers led by Xiangzhong Yang, a professor at the University of Connecticut, cloned a Japanese black beef bull and Holstein dairy cow using somatic cell nuclear transfer, the same technique used to clone the sheep Dolly in year 1996.
The researchers compared the meat and milk from the clones to that of animals of similar age, genetics, and breed created through natural reproduction. Analysis of protein, fat, and other variables routinely assessed by the dairy industry revealed no significant differences in the milk.
The researchers also examined more than 100 meat quality criteria, of which 90 percent showed no noteworthy variations. But about eight variables related to the amount of fat and fatty acids in the meat were significantly higher in the meat from the clones. But the authors said these higher fat levels are within beef industry standards.
"In this study, we conducted extensive comparisons of the composition of milk and meat from somatic cloned animals to those from naturally reproduced comparator animals," Yang said.
"We found no significant differences between clones and their controls; and all parameters examined for the clones in this study were within the normal range of beef and dairy products approved for human consumption."
Debate has surrounded whether it is safe to eat cloned livestock and their offspring. US federal regulators began looking at cloned food safety four years ago as it became clear that the cloning technique that led to the 1996 birth of Dolly the sheep had commercial potential.
In year 2001, the US Food and Drug Administration (FDA) named a science committee from The National Academy of Sciences to identify any safety concerns that somatic cloned animals might present in humans, animals and the environment.
The committee reported that clones present "a low level of food safety concern," but it also stated that science-based information on the compositions of the clones' products is needed to reduce the food safety concerns.
In a follow-up report of its risk assessment in 2003, the agency concluded that cloned animals and their offspring posed no increased risk to food safety.
However, the FDA emphasized that it had "made no policy decision that these products might be sold" and asked the industry to voluntarily keep clones and their offspring out of the food supply until a final decision was made.
"The data generated from our match-controlled experiments provide new science-based information desired by regulatory agencies to address public concerns about the safety of meat and milk from somatic animal clones," Yang noted.
"Information on the composition of meat and milk from somatic clones of food animals is extremely limited and highly desired."
Providing a cautionary note, Yang said that this study was conducted with a relatively small number of diary and beef clones and the clones of each breed were derived from a single genetic source.
"The experiments presented here are a pilot study to provide guidelines for more conclusive studies with larger numbers of clones from different genetic backgrounds, in order to further increase the consumers' confidence concerning product safety of somatic cloned food animals," he said.
(Xinhua News Agency April 12, 2005)
