<p style="text-align: justify;"><b>Dietary Exposure</b></p>

<p style="text-align: justify;">Humans consume relatively little whole kernel or processed maize, compared to maize-based food ingredients. Maize is a raw material for the manufacture of starch, the majority of which is converted to a variety of sweetener and fermentation products, including high fructose syrup and ethanol. Maize oil is commercially processed from the germ. These materials are components of many foods including bakery and dairy goods, and the human food uses of grain from DAS-59122-7 are not expected to be different from the uses of non-transgenic field maize varieties. As such, the dietary exposure to humans of grain from insect resistant hybrids will not be different from that for other commercially available field maize varieties.</p>

<p style="text-align: justify;">The highest levels of expression of Cry34Ab1 and Cry35Ab1 in the grain of DAS-59122-7 were measured to be 117 mg/kg and 1.83 mg/kg, respectively. The actual exposure in the diet is expected to be lower than this due to a number of factors including protein degredation during transport, storage and processing of the grain. The level of PAT expressed in the grain was below the limit of quantitation for this protein (0.06 mg/kg).</p>

<p style="text-align: justify;"><b>Toxicity and Allergenicity</b></p>

<p style="text-align: justify;">The acute oral toxicity of the two Cry proteins was studied, both individually and combined, using single dose studies in mice. The mice received either a single dose of 2700 mg/kg bw Cry34Ab1, 1850 mg/kg bw Cry35Ab1 or 482 mg/kg bw Cry34Ab1 and 1520 mg/kg bw Cry35Ab1 together, and observed for two weeks. Apart from some fluctuations in body weights common in large dose oral gavage studies, there were no clinical signs noted during the study. All mice survived the observation period and there were no gross pathological changes noted upon post mortem examination of the mice.</p>

<p style="text-align: justify;">Extensive animal testing has shown that the PAT protein is non-toxic to humans and animals and this gene has been expressed in other transgenic crops approved in a number of countries. An acute oral toxicity study with 5000 mg/kg bw of the PAT protein showed no effects in mice.</p>

<p style="text-align: justify;">The protein concentrations tested were orders of magnitude greater than the dose range for this endpoint typically associated with protein toxins. Additionally the PAT protein present in this corn has been extensively studied and has been found safe for consumption in food or feed according to a consensus document concerning the genes and associated enzymes that confer tolerance to phosphinothricin herbicide (OECD, 1999).</p>

<p style="text-align: justify;">Based on the expression levels of these proteins in grain and dietary intake data, exposure to these proteins would be extremely low. The novel proteins were not homologous to known food allergens, as established by amino acid sequence comparisons with allergenic proteins from extensive computerized databases. In digestibility studies using simulated mammalian gastric fluid, the novel proteins were more rapidly digested than non-allergen protein controls. The Cry34Ab1 and Cry35Ab1 proteins are completely inactivated by exposure for 30 min to 90&ordm;C and 60&ordm;C respectively, indicating that both proteins are heat labile. Based on the preceding evidence, the novel proteins expressed in this corn line do not share characteristics of known food allergens.</p>

<p style="text-align: justify;"><b>Nutritional and Compositional Data</b></p>

<p style="text-align: justify;">Forage and grain from DAS-59122-7 maize, grown at three locations, were analyzed for nutritional composition and compared to a non-transgenic maize control which was derived from the parental line Hi-II, and to published literature values. Samples for analysis were collected from field trials grown at six different locations.</p>

<p style="text-align: justify;">Forage was harvested at the dough stage (R4) and was analyzed for proximates (crude protein, crude fat, moisture, ash, carbohydrate, acid detergent fibre (ADF), neutral detergent fibre (NDF)), and minerals (calcium and phosphorus). No significant differences in the levels crude protein, crude fat, crude fibre, ADF and NDF were observed between DAS-59122-7 and the non-transgenic control. While significant differences were observed in the levels of ash, carbohydrates, calcium and phosphorus, these values were within the ranges reported in the literature for conventional maize hybrids.</p>

<p style="text-align: justify;">Grain samples were obtained from mature (growth stage R6) plants and analyzed for the several components, including proximates (crude protein, crude fat, moisture, ash, carbohydrate, acid detergent fibre and neutral detergent fibre); minerals (calcium, phosphorus, magnesium, copper, iron, manganese, potassium, sodium, and zinc); amino acids; fatty acids; vitamins (A, B1, B2, folic acid, E ); anti-nutrients (phytic acid, trypsin inhibitor, raffinose); and secondary metabolites (ferulic acid, <i>p</i>-coumaric acid, furfural).</p>

<p style="text-align: justify;">Statistical analysis of the mean levels of proximates across all locations revealed no significant differences between DAS-59122-7 and the non-transgenic control, with the exception of crude protein, ash, and carbohydrates. The levels of crude protein and ash were higher, and carbohydrate levels were lower in DAS-59122-7 compared to the control line. Statistically significant differences were reported in the mean levels of most of the fatty acids measured. The levels of linoleic and linolenic acid were higher, while palmitic and stearic acid levels were lower in DAS-59122-7 compared to the control. No significant differences were observed in the levels of oleic acid. The levels of nine of the amino acids measure, <i>i.e.</i>, tryptophan, isoleucine, histidine, valine, leucine, arginine, phenylalanine, proline and tyrosine, were higher in DAS-59122-7 compared to the control. No significant differences were observed in the levels of minerals, except for calcium, which was higher in the transgenic line. Statistically significant differences were observed in the levels folic acid and vitamin E. Despite all of the observed statistically significant differences between DAS-59122-7 and the non-transgenic control, all of the nutritional component values were within the ranges reported in the literature for conventional maize hybrids.</p>

<p style="text-align: justify;">The levels of the antinutritional compounds phytic acid, trypsin inhibitor and raffinose, as well as the secondary metabolites ferulic acid, <i>p</i>-coumaric acid, and furfural were determined in the grain. Phytic acid occurs naturally in maize and other cereals. It is indigestible by humans and non-ruminant livestock, and inhibits the absorption of iron and other minerals. Trypsin inhibitor interferes with enzymes involved in protein digestion. Raffinose is an oligosaccharide found in cereals and legumes which is indigestible in humans and monogastric livestock, thereby limiting the amount of metabolizable engery in foods and feeds. Ferulic acid and <i>p</i>-coumaric acid are compounds which become covalently linked to hemicelluloses during cell wall development. In ruminants, these compounds inhibit cell wall degradation by rumen microorganisms. Furfural is an aromatic aldehyde which can result from the dehydration of pentose sugars in cereals. No significant differences were observed in the levels of these antinutrients, and the secondary metabolites ferulic acid and <i>p</i>-coumaric acid, between DAS-59122-7 and the non-transgenic control maize line. Furfural was not detected in any of the samples analyzed.</p>

<p style="text-align: justify;">The results of these compositional analyses led to the conclusion that DAS-59122-7 forage and grain is not different in nutritional and antinutritional composition compared to maize hybrids currently marketed, grown and consumed.<br />
No introduced health concerns would be expected to be associated with the consumption of corn event DAS-59122-7 compared with its non-transgenic parent. DAS-59122-7 corn is deemed to be similar to the non-transgenic parental strain of corn in terms of being an acceptable food source.</p>
