Evaluation of the safety and nutritional equivalence of a genetically modified cottonseed meal in a 90-day dietary toxicity study in rats

Abstract

Meal prepared from Cry1F/Cry1Ac transgenic/genetically modified cottonseed (WIDESTRIKE™ Insect Protection, hereafter referred to as WIDESTRIKE™) was compared to cottonseed meal prepared from four conventionally bred lines of cotton (three commercial non-transgenic line controls (PHY72, PHY78 and 98M-2983), and a near isoline non-transgenic control (PSC355) in a 90-day dietary study to evaluate safety and nutritional equivalence. Diets were formulated with 10% WIDESTRIKE™ cottonseed meal equivalent to 7235 mg/kg/day for males and 7935 mg/kg/day for females. Animals were evaluated by cage-side and hand-held detailed clinical observations, body weight, and feed consumption. Functional tests, motor activity and ophthalmic examinations were conducted pre-exposure and prior to study termination. Standard hematology, clinical chemistry, prothrombin time and urinalysis parameters were evaluated. All rats had a complete necropsy and selected organs were weighed. Histopathologic examinations were performed on all rats fed the diets containing the near isoline non-transgenic control or WIDESTRIKE™. Following 90 days of feeding, no adverse effects were observed during the conduct of clinical observations or in any of the parameters measured in this study. This study demonstrated that rodent diets prepared with 10% cottonseed meal from WIDESTRIKE™ cottonseeds do not produce any untoward effects and are nutritionally equivalent to cottonseed meals prepared from other, non-transgenic cottonseeds.