[FairWitness]

"Pederson decided to stop feeding his 450 sows with GM soybean, replacing them with fishmeal and non-GM soybean instead. "

You are correct. Taken at face value, this is not a valid experiment from which to draw conclusions. "Change one variable at a time", i.e., add fishmeal to GM soybean, and/or replace GM soybean with non-GM soybean with no other changes.

[Chickensoup]

I am no fan of GMO foods but I want them to stand or fall with decent data.