Hello everyone, my name is Paola Lancheros, I am a second-year master’s student under Dr. Hans Stein. And today I will discuss about “Enhanced torula yeast has increased nutritional value compared to fish meal when fed to weanling pigs.” Today I will start with an introduction about yeast in diets fed to pigs, and then I will talk about the nutritional content of torula yeast and the importance of this feed ingredient. Afterwards, I will show you some results of three experiments conducted in our lab. The first one is about amino acid digestibility. Then, the second one is about concentrations of digestible and metabolizable energy. And the last one is about phosphorus digestibility. And at the end, I will conclude the podcast talking about the effects of the torula yeast on the pigs. So first of all, let’s start with some background about the torula yeast. Yeast is considered as a eukaryotic single-celled microorganism and is considered a source of protein that may be comparable with fish meal. And additionally, it has some immunostimulating properties. In general, yeast and fish meal have similar amount of protein, lipids, carbohydrates, vitamins, and minerals. However, I would like to point out here that it may change based on the type of yeast that we are using. And now, talking about the amino acids, yeast compared with fish meal has similar content of lysine, methionine, and cysteine, and yeast used to have greater content of tryptophan and threonine. Now let’s move on to talk about the process to obtain yeast in general. First of all, the culture of yeast is added to the medium that has the right conditions to grow. It has the right temperature, nutrients, and pH. And then we start escalating the process. This is a fermentation process that happen in a biodigester, and at the end, the last step is a purification and drying of the yeast to be included in the diet. But, what is different with this type of yeast that is called torula? One of the main differences is that in the fermentation medium, we can use lignocellulosic products. And why do we use lignocellulosic products? It is because that is a source of carbon that the yeast can take to grow up. Torula yeast has several advantages. First of all, it has a good nutritional value that I will talk in depth in the next slides. It is traceable from the source to the end of the product. It is a renewable source. And in terms of production, it has several advantages since it doesn’t rely on the weather, therefore we can have production of yeast the whole year. And last but not least, it has a lower carbon footprint. Now, from here until the end, I will talk about a specific source of yeast—that is, the torula yeast. Here, we can see the gross energy of torula yeast vs. the fish meal. In orange, torula yeast and in blue, we have the fish meal. And as you can see, torula has greater value for gross energy. In terms of protein, fish meal has greater value than torula yeast, as you can see in the graph. Now, talking about calcium and phosphorus, we can observe that fish meal has greater value for calcium as well as for phosphorus. Now, let’s move on to the amino acid content. Here we can observe the value for torula yeast in orange, and in blue, we can observe the values for fish meal. And as you can see here, fish meal has greater values than torula yeast for indispensable amino acids. However, besides considering the nutritional value of an ingredient, we have to evaluate the digestibility. Therefore, we have the hypothesis that the standardized ileal digestibility of crude protein and amino acids and the digestible and metabolizable energy, as well as the standardized total tract digestibility of phosphorus in torula yeast is not different than in fish meal. So, let’s move on to the results that we obtained in the experiments that we conducted in our lab. In the first experiment, we utilized 6 pigs with an initial body weight of 11.7 kg, and all of them were cannulated. Pigs were fed with 3 different diets: The first one is a cornstarch-based diet with torula. The second one is the same but instead of torula, we used fish meal. And in the third one, it was an N-free diet to calculate endogenous losses. In this experiment, we analyzed the standardized ileal digestibility of crude protein. And in blue, you can see the results for torula yeast and in orange, you can see the results from fish meal. And as you can observe, we obtained greater values for torula yeast than for fish meal. We also analyzed the standardized ileal digestibility of indispensable amino acids. And here we can observe the values for torula yeast, and in blue, for fish meal. And as you can see, we obtained greater values for torula yeast. However, it is important to take into account the concentration of those indispensable amino acids in the ingredient. Therefore, we multiplied the concentration of the amino acids in the ingredient by the standardized ileal digestibility, and then we obtained the following results. So here in orange, we have the results for torula yeast, and in blue, the results for fish meal. Leucine and histidine has pretty much the same values. And we obtained greater values in fish meal for arginine, lysine and methionine. In contrast, we observed greater values of torula yeast for the rest of the amino acids, that include isoleucine, phenylalanine, threonine, tryptophan, and valine. We should keep in mind that one of the deficient amino acids is tryptophan, and in this case, this is greater in torula yeast. With this experiment, we can conclude that the standardized ileal digestibility of amino acids in torula yeast compared with fish meal is greater or the same in torula yeast. The second experiment, as I mentioned, is about energy. In this experiment, we used 24 pigs with an initial body weight of 14.4, and the pigs were fed with three different diets. The first one is a corn-based diet. The second is also corn-based but with the inclusion of torula. And the third one is a corn base, but instead of having torula yeast, it has fish meal. In this experiment, we analyzed the apparent total tract digestibility of gross energy for the three ingredients, and as you can see in the graph, we didn’t find any significant difference among sources. Now, talking about the digestible energy, again, we have the three ingredients corn, torula yeast, and fish meal, and as you can see, we didn’t find any significant difference among sources. In contrast, for metabolizable energy, corn values were greater than in torula yeast and fish meal. But, as you may remember, in the hypothesis, we want to compare torula yeast and fish meal, and between those two sources, we didn’t find any significant difference. Therefore, talking about energy, it wasn’t any significant difference for apparent total tract digestibility, no differences in digestible energy, and no differences in metabolizable energy. Therefore, in terms of energy, if we replace fish meal with torula yeast, it won’t have any effect. The last experiment is about phosphorus digestibility. In this experiment, we utilized 32 pigs with an initial body weight of 11.9 kg. The pigs were fed with four different diets. The first one is a cornstarch-based diet with the inclusion of torula yeast. The second one is a cornstarch-based diet with the inclusion of fish meal. And the third one is the same as the first one but with the inclusion of 1000 phytase units. The last one is the same as the second one but with the inclusion of 1000 phytase units. In this experiment, we analyzed the standardized total tract digestibility of phosphorus in the diets with and without the inclusion of phytase. With no phytase inclusion, we found greater results in torula yeast than in fish meal. Now analyzing the diets with the inclusion of phytase, we found also greater values in torula yeast than in fish meal. But we didn’t find any effect in the inclusion of phytase, and we didn’t find any interaction between ingredient and phytase. But, again, we have to keep in mind the concentration of phosphorus that we have in the ingredient. It is why we multiply the concentration of phosphorus by the standardized total tract digestibility, and we found that it is greater in fish meal than in torula yeast. But we didn’t find any effect in the inclusion of phytase. Now, here, we observe the same behavior with the inclusion of phytase, but we didn’t find any interaction between the ingredient and the inclusion of phytase. Talking about calcium, we observe here the diets without the inclusion of phytase, and we can see that torula yeast had greater values for apparent total tract digestibility of calcium than fish meal. And we observe the same behavior with the inclusion of phytase. Therefore, the inclusion of phytase didn’t have any effect on the digestibility, and we didn’t find any interaction between the ingredient and the inclusion of phytase. In conclusion, for phosphorus, the standardized total tract digestibility of phosphorus is greater in torula yeast. However, the inclusion of phytase didn’t have any effect. As an overall conclusion, the standardized ileal digestibility of amino acids was greater in yeast than in fish meal. Talking about energy, we didn’t find any significant difference between torula yeast and fish meal. And, for the digestibility of phosphorus, it was greater in torula yeast than in fish meal. But we didn’t find any effect of inclusion of phytase. Therefore, the enhanced torula yeast can be included in diets for weanling pigs at the expense of fish meal. But we have to take into account the differences in the concentration of standardized digestible amino acids between the two ingredients. With that, I would like to acknowledge Arbiom for the financial support. And also to all of the members from the Stein Monogastric Nutrition Laboratory. And if you want to learn more about this or other topics in nutrition, please visit our website at nutrition.ansci.Illinois.edu.