Egyptian researchers found Bt corn was not substantially equivalent to non-GM parent and was toxic to rats, even after only 91 days of feeding.
These findings arose from three studies published in 2012 and 2013 on a type of GM insect resistant Bt corn developed using Monsanto's MON810 trait.
One study showed that the GM corn was not substantially equivalent to the non-GM parent.
A second study examined the effects on rats of a diet containing the GM maize. The study found that the GM corn diet caused increased or decreased organs/body weight or changes in blood biochemistry that indicated possible toxicity.
In the third study, histopathological examination was carried out on the rats fed the GM maize, and the results were compared with rats fed non-GM maize. The study found clear signs of organ pathology in the GM-fed group, especially in the liver, kidney, and small intestine. An examination of the testes revealed necrosis (death) and desquamation (shedding) of the spermatogonial cells that are the foundation of sperm cells and thus male fertility - and all this after only 91 days of feeding.
 Abdo E.M. et al. Chemical Analysis of BT corn "Monsanto810:Ajeeb-YG" and its counterpart non-Bt corn "Ajeeb" IOSR Journal of Applied Chemistry (IOSR-JAC) e-ISSN:2278-5736. Vol 4 Issue 1 (Mar-April, 2013) pp55-60
Commercialization of biotech crops has started since 1996, where the cultivated area of these crops was increased from 1.7 million hectares in 1996 to 170.3 million hectares in 2012 according to the latest statistics in 2012. Bt corn "MON810: Ajeeb YG®" is one of these crops that express endotoxin from Bacillus thuringiensis (Bt) throughout the whole plant. This study was designed to assess the safety of Bt corn by comparing its compositional chemical analysis with its conventional counterpart "Ajeeb". Moisture content, crude fat, total saccharides, starch, & crude fiber were determined; sodium, potassium, magnesium, calcium and phosphorous content were measured, tannins & phytic acid were determined as anti-nutrients. Amino acids and fatty acids profiles were also evaluated. Results indicated the presence of significant differences between both of Bt corn and its counterpart.
 Gab-Alla, A et al. Morphological and Biochemical Changes in Male Rats Fed on GM corn (Ajeeb YG) Journal of American Science 2012 8(9)
This study was designed to evaluate the safety of genetically modified (GM) corn (Ajeeb YG). Corn grains from Ajeeb YG or its control (Ajeeb) were incorporated into rodent diets at 30% concentrations administered to rats (n= 10/group) for 45 and 91 days. An additional negative control group of rats (n=10/group) was fed AIN93G diets. General conditions were observed daily, total body weights were recorded weekly. At the termination of the study periods, some visceral organs (heart, liver, kidneys, testes and spleen) and serum biochemistry were measured. The data showed several statistically significant differences in organs/body weight and serum biochemistry between the rats fed on GM and/or Non-GM corn and the rats fed on AIN93G diets. In general, GM corn sample caused several changes by increase or decrease organs/body weight or serum biochemistry values. This indicates potential adverse health/toxic effects of GM corn and further investigations still needed.
 El-Shamei, ZS et al, Histopathological Changes in Some Organs of Males Rats Fed on GM corn
(Ajeeb YG) Journal of American Science 2012 8(10)
Ajeeb YG is a genetically modified (GM) insect resistant corn produced by incorporated the MON 810 (Monsanto) borer resistance trait in the best corn germplasm Ajeeb. The safety of Ajeeb YG corn was assessed by comparison of toxicology response variables in rats consuming diets containing Ajeeb YG with those containing Ajeeb corn grains. Corn grains from Ajeeb YG or Ajeeb were incorporated into rodent diets at 30% concentrations administered to rats (n=10/group) for 91 days. An additional negative control group of rats (n=10/group) were fed AIN93G diets. Rats fed on GM corn showed histopathological changes. Liver displayed cytoplasmic vacuolation of centrolobular hepatocytes and fatty degeneration of hepatocytes. Kidneys showed congestion of renal blood vessels and cystic dilatation of renal tubules. Testes revealed necrosis and desquamation of spermatogoneal germ cells lining seminiferous tubules. Spleen showed slight lymphocytic depletion and splenic congestion. Small intestine showed hyperplasia, hyperactivation of mucous secretory glands and necrosis of intestinal villi were detected. Due to these observations, we suggest that the risk of GM crops cannot be ignored and deserves further investigations in order to identify possible long-term effects, if any, of GM food consumption that might help in the post market surveillance.