Slide 1 Hi. My name is Dr. Sarah Cervantes-Pahm, and I would like to present to you our results of our research entitled, "The apparent ileal digestibility and apparent total tract digestibility of gross energy and nutrients in cereal grains fed to growing pigs." Slide 2 Cereal grains are important sources of energy for humans. And in human diets, cereals are usually refined into flours and incorporated in breads, pastries, and crackers, and they are consumed as such. The current dietary recommendation is to reduce intake of refined grains, such as flours, and to increase intake of whole grains. And this recommendation is based on the Dietary Guidelines for Americans 2010, released by USDA. Slide 3 But what are whole grains? Whole grains are defined by the American Association of Cereal Chemists in 2000 as the "intact, ground, cracked, or flaked caryopsis, whose principal anatomical components, the starchy endosperm, germ and bran, are present in substantially the same relative proportions as they exist in the intact caryopsis." Therefore, for whole grain ingredients, the three major components -- bran, germ, and endosperm -- must be present in the same amount as they occur in the grains in their native state. Slide 4 So the objective of this experiment was to determine the apparent ileal digestibility and apparent total tract digestibility of gross energy and nutrients in eight whole cereal grains. However, for this podcast, we will only present the AID of carbohydrates and the metabolizable energy of these cereal grains. The second objective was to determine the DE, or the digestible energy, and the ME, or metabolizable energy, in these cereal grains. The cereal grains that we worked with were yellow dent corn, NutriDense corn, dehulled barley, dehulled oats, polished rice, rye, sorghum, and wheat. Please note that except for the NutriDense corn, all the cereal grains used in this experiment were grains consumed normally by humans. Slide 5 Let us start by looking at the gross energy of the cereal grains. There are three things that can be observed in this slide. First is that the GE in dehulled oats, in yellow, is greater than the other cereal grains, and the GE is at 4,172 kcal/kg. Second, the gross energy in rice, which is in the blue bar, is at 3,717 kcal and is less than the other cereal grains. For the remaining cereal grains, the GE ranged between 3,878 and 3,972 kcal/kg. Slide 6 Looking at the concentration of acid hydrolyzed ether extract in these grains, we can see that again, dehulled oats contained more ether extract at 7.5% than the other cereal grains, whereas rice contained the least amount of ether extract at 0.9%. The fat concentration for the remaining cereal grains were between 2.4 to 5.6%. Slide 7 Looking at crude protein, dehulled oats contained relatively more protein, at 13.1%, and yellow dent corn contained only 8%, relatively less than in the other cereal grains. But in general, the range of crude protein among the remaining cereal grains were between 8.8 to 12.1%. Slide 8 Total starch was high in rice, at 75%, whereas rye and wheat contained only 56.8 and 61.6% total starch respectively. All the other cereal grains contained starch at a range between 64 to 67%. Slide 9 Looking at the concentration of resistant starch in these grains, we could see that sorghum contained significant amounts of resistant starch at 18.5%, followed by yellow dent corn and NutriDense corn at 10 to 11%. Rice, rye, and wheat contained about 1 to 2% of resistant starch, but dehulled oats and dehulled barley has a little bit more concentration of resistant starch than these three grains at about 6%. Slide 10 Looking at the concentration of total dietary fiber, we could see that rye contained the most concentration of TDF at 11.7%, and rice had the least concentration of TDF at 1.1%, with the remaining cereal grains containing between 6.4 to 10% TDF. Slide 11 So for this experiment, we hypothesized that for cereal grains that has a high concentration of resistant starch and TDF, such as sorghum and rye, we expect these cereals to have a lower digestibility of starch. And conversely, for cereal grains that has a low concentration of resistant starch and a low concentration of TDF, such as rice, we expect these grains to have a high digestibility of starch. Slide 12 And we also hypothesized that the DE and ME of the cereal grains will be dictated, not only by starch disappearance or digestibility, but the digestibility of all the other energy-yielding nutrients in the cereal grain. Slide 13 So for our results, this slide shows the apparent ileal digestibility of starch. And let's look at rice first, in the blue bar, and as we could see, starch digestibility in rice is at 98.6%. And if we looked at the concentration of TDF and resistant starch at the bottom of the graph, we could see that rice, as was mentioned earlier, had a low concentration of TDF and resistant starch. So, so far our hypothesis is holding that cereals with a low concentration of TDF and resistant starch would have high starch digestibility. Slide 14 However, if we looked at other cereal grains such as NutriDense corn in blue, dehulled oats in yellow, and wheat in purple, we could see that the digestibility of starch in these cereal grains were not different from rice. But if we looked at the concentration of TDF and resistant starch in NutriDense corn, dehulled oats, and wheat, they have substantially greater concentrations of TDF and resistant starch compared to that of rice. So this indicates that digestibility of starch in cereal grains are not only dictated by the concentration of TDF and resistant starch in these grains, and that other factors affect the digestibility of starch in grains. Slide 15 If we also looked at yellow dent corn in red and NutriDense corn in blue, we could see that the concentration of TDF and resistant starch between these two grains were fairly similar. But if we looked at the digestibility of starch, the digestibility of starch in NutriDense corn were greater than that of yellow dent corn, which just proves that there are other factors that dictate the digestibility of starch in cereal grains. Slide 16 If we looked at the apparent ileal digestibility of starch in dehulled barley in green, rye in pink, and sorghum in bright purple, we could see that the digestibility of starch in these cereal grains were relatively less than the other cereal grains. And this is important because, for cereal grains that has a low digestibility of starch, we expect that less starch is absorbed as glucose, and this is particularly important when it comes to diabetes management. Slide 17 This slide shows the metabolizable energy of the cereal grains, and as we could see, dehulled oats has a greater ME at 4,180 kcal/kg dry matter compared to the other cereal grains. Rye and sorghum has less metabolizable energy relative to the other cereal grains, and this fact is important when it comes to weight management. Slide 18 So in conclusion, the apparent ileal digestibility of starch is determined by factors other than the concentration of TDF and resistant starch in the grain. And other energy yielding nutrients, such as acid ether extract and protein, contribute to the ME of the cereal grains. Slide 19 So the implication of this experiment is that rye and sorghum may be the ideal grain for diabetes and weight management because of its relatively low starch disappearance and caloric value. However, if the objective is to increase energy intake, dehulled oats, dehulled barley, wheat, and rice are preferred grains. Slide 20 We constantly update our website for the results of new researches, so you are welcome again to visit our website at nutrition.ansci.illinois.edu for more updates. Thank you.