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New scientific review of genetically engineered feeds in livestock diets

New scientific review concludes no adverse effects of genetically engineered feeds in livestock diets

American Society of Animal Science

An article published in the peer-reviewed Journal of Animal Science concludes feeding livestock diets that contain genetically engineered (GE) crops has no impact on the health or productivity of those animals. In a thorough review of scientific literature and field data sets, the article documents evidence that the performance and health of food-producing animals fed GE crops are comparable with those of animals fed non-GE crops.

Since their introduction in 1996, GE feed crops have become an increasing component of livestock diets. Today, more than 95 percent of U.S. food-producing animals consume feed containing GE crops. Studies that involve feeding GE crops to livestock are used to evaluate the safety of these crops.

Recently, University of California-Davis researchers reinforced the consistency of these studies in an unprecedented review article that examines nearly 30 years worth of livestock-feeding studies, representing more than 100 billion animals.

In the review, posted online September 2 in the Journal of Animal Science, Alison Van Eenennaam, Cooperative Extension Specialist in Animal Biotechnology in the Department of Animal Science at the University of California-Davis, and research assistant Amy Young examine feeding data from 1983 (13 years before GE crops were introduced) through 2011 (when GE feed use exceeded 90 percent).

The review also examines 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," state the authors.


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, ASAS has elected to make the full article immediately available in open-access form at

Note from the Editor of the Journal of Animal Science:

Genetically engineered crops are used to produce feeds for livestock and poultry.

As Editor-in-Chief of the Journal of Animal Science, I invited Dr. Alison Van Eenennaam to conduct a thorough review of the scientific literature and evaluate the effects of GE feed ingredients on the animals consuming those feeds.

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.

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.

Gregory S. Lewis, Ph.D.
Journal of Animal Science
American Society of Animal Science
PO Box 7410
Champaign, Illinois 61826-7410

The Journal of Animal Science is a peer-reviewed scientific publication. JAS copyright is held by the American Society of Animal Science (ASAS). ASAS is a professional society. In order to ensure scientific integrity, JAS does not accept advertising revenue and any and all sponsorships of a paper published in JAS are listed in the published version of the paper. This paper was an invited review and neither JAS, ASAS, nor the authors received any sponsorship or payment associated with publication of this article.

The American Society of Animal Science fosters the discovery, sharing and application of scientific knowledge concerning the responsible use of animals to enhance human life and well-being. Our members work in agriculture because they love animals and believe feeding our families, friends, and communities is important.

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