A study by scientists at Leipzig University found that Roundup herbicide negatively impacted the gastrointestinal bacteria of poultry tested in vitro. The researchers found that highly pathogenic bacteria resisted Roundup, whereas beneficial bacteria were moderately to highly susceptible to it. The study provides a scientific basis to farmer reports of increased gastrointestinal disease in animals fed GM Roundup Ready soy, which is tolerant to Roundup.
An interesting video shows how Danish egg producer Claus Storgaard found drastic improvements in the health and egg production of his hens after changing from GM to non-GM soy feed.