Slide 1 Good afternoon. I am Hans H. Stein, and I am a professor in the Department of Animal Sciences at the University of Illinois. I would like to visit with you today about the energy value of low fat and de-oiled distillers dried grains with solubles when fed to pigs. Slide 2 Before we get into the specifics, I do want to remind everyone that when we talk about energy, energy comes from oxidizing certain nutrients in the diet. And we have six different classes of nutrients: water, proteins, carbohydrates, lipids, vitamins, and minerals. And when a pig eats a diet, the diet usually contains all of these nutrients. However, energy is not a nutrient, but the pig can oxidize protein, carbohydrates, and lipids and from that oxidation, the pig will obtain the energy. So the total amount of energy that a pig can obtain from a diet comes from the oxidation of protein, carbohydrates, and lipids. Slide 3 If we look at the concentration of metabolizable energy in different feed ingredients, we can see that corn contains close to 4000 kcal/kg dry matter, and DDGS also contains close to 4000 kcal/kg dry matter. So those two values are not different. That means that conventional DDGS contains practically the same amount of metabolizable energy as corn. However, high protein DDG contains more energy than both corn and conventional DDGS. But if we feed corn germ, we also are at a value that is a little bit less than 4000 kcal/kg dry matter, so again, this value is not different from corn. So corn, conventional DDGS, and corn germ, they all contain about the same amount of metabolizable energy. Slide 4 The values that have been determined for energy concentration in DDGS was determined in conventional DDGS, which contains usually between 9 and 12% fat. Recently, the ethanol industry has started a process of reducing the concentration of oil in the DDGS that they are marketing. And we therefore now see sources of DDGS that contain less than 9% oil. Slide 5 We actually have three different sources of DDGS in the market at this point. We have normal DDGS, which contains more than 9% fat as I just mentioned, we have what we call low fat DDGS, which is produced after ethanol producers have centrifuged the solubles, so they get the fat out of the solubles, and that will result in DDGS that contains between 5 and 9% fat. We also have a few producers who use an extraction process to remove as much oil as possible from DDGS, and in that case, we get DDGS that contains less than 5% and sometimes down to 3 or 4% fat. So, we now have three different sources of DDGS in the marketplace, and the question therefore is: how much energy can a pig obtain from each of these three sources? Slide 6 Unfortunately, we don't have any research in which all three sources of DDGS have been compared. However, we have some recent data here from the University of Illinois where three sources of DDGS were used. We had conventional DDGS that contained 9.6% fat, we had a low fat DDGS that contained 8.1% fat, and we had another low fat DDGS that contained 6.6% fat. We do note here that as fat concentration is reduced from 9.6 to 8.1 to 6.6, the concentration of crude protein is increased from just above 25% to more than 27%. And remember, the pig does get energy from both fat and crude protein, so when fat goes down and crude protein goes up, the energy that the pig can get may not be much changed. And we also note that the concentration of NDF, which is the major source of carbohydrates in DDGS, that also is increased when oil concentration is reduced. So again, pigs may get a little bit more energy from the NDF fraction of the lower fat DDGS sources than the conventional DDGS. However, when we analyze the total amount of energy, we do note here that the concentration of gross energy is reduced in the low fat sources of DDGS compared with the conventional DDGS. Slide 7 We fed these three sources of DDGS to pigs, and we determined the concentration of metabolizable energy in each of these sources of DDGS and we compared that with what we have for corn. And you'll see in this case, we get a value for corn that's just about 4000 kcal/kg dry matter, exactly as we've done before. The conventional DDGS that we used in this case was actually a little bit better than corn, and we obtained more metabolizable energy from the conventional DDGS than we did from corn. We do note that there is a small reduction in the concentration of metabolizable energy in the low fat DDGS sources; however, in both sources, we got energy values that are just about the same as in corn. And they were actually not significantly different from conventional DDGS. So, what this tells us is that although the fat concentration was reduced from more than 9% to about 8% and 6% in the low fat sources, the pigs actually had almost the same amount of metabolizable energy from these sources. And we do believe that one of the major reasons we observed this is that as the concentration of fat in the DDGS was reduced, the concentration of both protein and fiber went up, and that partly offsets the reduced energy that comes from fat. Slide 8 Another reason why we don't see a greater reduction in the metabolizable energy in the low fat sources is that the digestibility of fat in DDGS is actually not very high. And we can see here the true ileal digestibility of different lipid sources; we have corn oil, corn, DDGS, corn germ, high protein DDG, and soybeans. And we will see for corn, DDGS, and corn germ, we have digestibility values that are around 60% or less. And that means that as we reduce the fat in DDGS, we don't reduce the amount of metabolizable energy and digestible energy quite as much as we would have expected because only about 60% of that fat is actually digested. Slide 9 If we look at de-oiled DDGS, we have an experiment here that was conducted at Kansas State University, and they used one source of de-oiled DDGS that contained 4% fat. The crude protein concentrations were 31%, and NDF were 34.6%. And the total gross energy concentration was 5098 kcal/kg dry matter. Slide 10 The researchers at Kansas State University determined the concentration of digestible energy and metabolizable energy in this source of de-oiled DDGS with a low concentration of fat. And they published values that were just around 3000 kcal/kg dry matter and actually for metabolizable energy, it was less than 3000 kcal/kg dry matter. So, in this case where most of the oil has been taken out, we don't see a value around 4000 kcal/kg dry matter as we saw for the low fat DDGS. Now we're down below 3000 kcal/kg dry matter. So taking out almost all the oil from DDGS using an extraction procedure results in de-oiled DDGS that contains significantly less energy than conventional DDGS and also contains less energy than the low fat DDGS, where only a portion of the oil was removed. Slide 11 We also have data from a Chinese experiment in which a conventional DDGS and de-oiled DDGS was used. And in this case, the concentration of fat in the conventional DDGS was 9.24%, and in the de-oiled DDGS, we had 3.5% fat. And as we've seen before, the concentration of both crude protein and NDF increased as the fat concentration was reduced. However, also as we saw before in the U.S. experiments, the concentration of gross energy was reduced as the concentration of fat in the DDGS was removed. Slide 12 The concentration of metabolizable energy in these two sources of DDGS was about 3500 kcal/kg dry matter in the conventional DDGS, and just above 3000 kcal/kg dry matter for the low fat DDGS. These values in this experiment were not significantly different. However, we do see that, as was the case in the previous experiment, the concentration of metabolizable energy is only around 3000 kcal/kg dry matter if we use a low fat DDGS that is de-oiled via extraction. So, if we have sources of DDGS that are down to 3 to 4% fat, we will have only about 3000 kcal metabolizable energy in these sources of DDGS, which is significantly less than we see in traditional U.S. DDGS. Slide 13 So in conclusion, the energy value in conventional DDGS is similar to corn. We have seen that in several experiments. In some experiments, we actually get a little bit greater digestibility value for DDGS. If we look at the energy value in low fat DDGS, and that is DDGS that contains between 6 and 9% fat, then we've seen that the concentration of metabolizable energy in low fat DDGS may be slightly less than in conventional DDGS, but not significantly reduce, and the main reason we don't see a greater reduction in low fat DDGS is most likely that the concentration of crude protein and the concentration of fiber is increased in low fat DDGS compared with conventional DDGS. So, the practical implication of using low fat DDGS is likely not very big. Unfortunately, we don't have production data for low fat DDGS compared with conventional DDGS, but with the small differences in metabolizable energy, it would not be expected that a producer could actually determine or measure the impact on pig performance of using low fat DDGS compared with conventional DDGS. However, unlike low fat DDGS, de-oiled DDGS contains significantly less digestible energy and metabolizable energy compared with conventional DDGS. And in that case, it is expected that a producer would be able to notice a significant reduction in pig performance if de-oiled DDGS is used. It is therefore recommended that de-oiled DDGS should be used in diets fed to pigs only if the price is discounted compared with the price for conventional DDGS. Slide 14 With that, I would like to thank you for your attention. If you're interested in more information about this issue, please visit our website. It's at nutrition.ansci.illinois.edu. All our publications are posted on this website, there's also a newsletter that is free, anyone can sign up for it, and there are podcasts, and there are many other things on this website.