A new study in a peer-reviewed journal indicates that pigs fed a diet containing genetically-modified corn and soy had more severe stomach inflammation and (in females) heavier uteri than pigs fed an equivalent diet in conventionally raised corn and soy that was not genetically-modified. You can read the full article describing research on an Iowa farm here (pdf). For a summary of key findings, click here or here. The pigs “were reared under identical housing and feeding conditions.”

These results are disturbing, considering that more than 90 percent of the corn and soybeans grown in Iowa are now “Roundup Ready” biotech varieties, sprayed with glyphosate, the key ingredient in Roundup herbicide. Many anecdotal reports have linked animal health problems to genetically-modified feed. At the 1000 Friends of Iowa annual meeting on June 8, large-animal veterinarian Arthur Dunham described nutritional deficiencies, fertility problems, and unexplained deaths that he has seen increasingly in the cattle and swine herds of his clients. Dunham has been in practice for nearly 40 years and presented data about lower levels of certain vitamins and minerals (including B-12, calcium, magnesium, phosphorus, potassium, manganese, and iron) in feed made from genetically-modified crops.

Monsanto and its allies dismiss such data as anecdotes and cite their own corporate-funded studies, which allegedly show the safety of GM crops. The new scholarly article describes the limitations of earlier research and calls for further studies on the subject. (Very few studies have been conducted over a time period longer than 90 days, for instance.) One Danish hog farmer saw big improvements after switching from genetically-modified feed, but Roundup crops are so dominant in this country that it can be hard for farmers to source animal feed that hasn’t been sprayed with glyphosate.