The safety of genetically engineered (GE), also known as genetically modified (GM), crops remains a controversial social, political, and global topic. Seeking to provide some resolve to the debate, a newly published article—the most comprehensive to date— in the peer-reviewed Journal of Animal Science has concluded feeding livestock diets that contain genetically engineered (GE) crops has no impact on the health or productivity of those animals.

Since their introduction in 1996, GE feed crops have become an increasing component of livestock diets. In fact, in the U.S. alone, more than 95% of food-producing animals consume feed containing GE crops. Additionally, the study noted, “Globally, countries that are cultivating GE corn and soy are the major livestock feed exporters.” But, countries are not on the same page in terms of GE approval, which has caused significant trade disruptions and according to the authors, “is likely to be increasingly problematic in the future as there are a large number of ‘second generation’ GE crops with altered output traits for improved livestock feed in the developmental and regulatory pipelines.”

“There is a pressing need for international harmonization of both regulatory frameworks for GE crops and governance of advanced breeding techniques to prevent widespread disruptions in international trade,” stressed the authors.

In November 2013, trade relations between China and the U.S. were disrupted after dried distillers grains with solubles (DDGS), an increasingly popular livestock feedstuff, were discovered to contain traces of Syngenta North America Inc.’s Agrisure Viptera MIR 162 GE corn trait. Following the discovery, China enforced a zero-tolerance policy which, as of April 2014, National Grain and Feed Association (NGFA) had estimated cost the U.S. grain industry an economic loss of $2.9 billion. NGFA also estimated that U.S. growers, grain handlers and exporters could sustain an even greater economic impact – up to $3.4 billion – during the 2014/15 marketing year if Chinese approval was not granted and Syngenta continued to market the product.

But, the topic goes far beyond global trade issues as many food companies, restaurants and non-governmental organizations (NGOs) have also used the controversy for marketing or social/political change.

The ongoing controversy surrounding the issue, prompted Dr. Greg Lewis, editor-in-chief of the Journal of Animal Science, to commission Dr. Alison Van Eenennaam, cooperative extension specialist in animal biotechnology in the Department of Animal Science at the University of California, Davis to do a thorough review of scientific literature and field data sets, representing more than 100 billion animals.

Van Eenennam, along with research assistant Amy Young, examined feeding data from 1983 (13 years before GE crops were introduced) through 2011 (when GE feed use exceeded 90%) and documented evidence that the performance and health of food-producing animals fed GE crops were comparable with animals fed non-GE crops.

Additionally, the researchers also examined the composition of products derived from animals fed diets containing GE feeds. “No study has revealed any differences in the nutritional profile of animal products derived from GE-fed animals,” stated the authors.

“The scientific evidence indicates clearly that the health, wellbeing, and productivity of animals consuming GE feeds are at least comparable to those of animals consuming conventional feeds,” stated Lewis. “I believe that information in this peer-reviewed article is essential for open-minded discussions of GE feeds and foods, and we have made this information freely available to the public.”

The review, entitled "Prevalence and impacts of genetically engineered feedstuffs on livestock populations," will appear in print and open-access in the October 2014 Journal of Animal Science. Due to the high level of interest in the article, American Society of Animal Science decided to post the full article in open-access form at www.asas.org.