Some Iowa growers suspect Bt corn responsible for decreased farrowing rates in sows
(May 20, 2002 – CropChoice news) – The April 29 edition of the Iowa Farm Bureau Spokesman featured a story about Jerry Rosman, a
Shelby County, Iowa farmer and his search for the cause of an 80 percent decrease in the farrowing rates of his sow herd.
He consulted with his veterinarian and others about the possible causes, including diseases and nutrient deficiencies. He learned of other
producers in the area who had been experiencing the same problem.
What his and the other operations had in common was the genetically engineered Bt corn the herds ate. Lab tests found that the transgenic
corn contained high levels of Fusarium mold. Rosman told the Farm Bureau Spokesman that researchers narrowed the Fusarium down to
four strains, and two of them (Fusarium subglutinans and Fusarium monlliforme) were consistent in all of the producers' samples.
One of the producers subsequently switched back to regular non-Bt corn, and pseudopregnancy is no longer a problem within that herd.
Rosman believes the problem manifested itself on his farm because he planted 100 percent of the same brand of genetically engineered Bt
seed corn and fed 100 percent of that corn to his livestock.
In a follow up article on May 13, 2002, the Iowa Farm Bureau Spokesman reported that shortly after the story detailing Rosman's situation
appeared, he has received many calls from producers who tell him of similar problems.
The calls primarily came from smaller producers who, like Rosman, feed their own corn and noticed a sharp decline in farrowing rates