Slide 1 Hi everyone. I'm Ferdinando Almeida, Ph. D. student at the Stein Monogastric Nutrition Laboratory, and this presentation today is about amino acid digestibility in hydrolyzed feather meal fed to pigs. Slide 2 This is the outline of the presentation. There will be an introduction, materials and method, results, discussion, and some implications of this research. Slide 3 Hydrolyzed feather meal is produced by steam hydrolyzing fresh poultry feathers, which is a co-product of the poultry processing industry. This process breaks down keratins, which are coiled polypeptide chains, to produce a more digestible high protein product and to reduce microbial contamination. Hydrolyzed feather meal is, however, not used extensively as a protein source in swine diets because there is limited data on the standardized ileal digestibility of amino acids in feather meal produced through current processing methods. Slide 4 This diagram shows how feathers are processed into feather meal. And we start with raw feathers. These raw feathers may be steam hydrolyzed, and then they go through a drying process, which then yields the feather meal. Blood may be added either before or after the steam hydrolysis process. Slide 5 There is some variability in the composition of feather meal, and this is because of the fact that blood can be added before or after hydrolysis as I mentioned before, and also the inclusion level of blood in this process is not standard among different processing facilities. The drying process may also cause some variation in the nutrient composition and utilization of feather meal, as a company may be using a flash dryer, a disc dryer, or other types of dryers, which all may cause some differences in the drying process overall. Also, the time of drying may be affected by the moisture of feather meal that is coming into the dryer, and this is dependent on the amount of steam that is used to hydrolyze the feathers. So these factors all combined, they may be some of the reason why we see so much variability in feather meal. Slide 6 Because there is limited digestibility data, and because of the nutritional variation in feather meal, the objective of this experiment was to determine the SID of crude protein and amino acids in four sources of feather meal, with or without addition of blood. Slide 7 Let's take a look at the materials and methods. Slide 8 This first table shows the nutrient composition of feather meals that were used in this experiment. So we have here gross energy in kcal/kg, we also have dry matter in percent, acid hydrolyzed ether extract, ash, calcium, and phosphorus concentration. So, we can see here that the feather meal that contained no blood, the gross energy was about 5,500 kcal/kg, whereas for feather meal with blood, that gross energy was about 5,400 kcal/kg. There was a little bit of variation, about 3.4%, in the gross energy concentration. And as we can see here, for dry matter, there is also little variation, about 3.2% only in the concentration of dry matter among the sources of feather meal. However, when we look at acid hydrolyzed ether extract concentration, we observe that for feather meal containing no blood, that is 9.4% versus 7% in the feather meal that contained blood. And the variation here is much higher than the variation observed for gross energy and dry matter; this is about 28% variation. Ash content is also quite variable, about 40% of variation, and calcium and phosphorus also have a certain degree of variation, about 8.3% for calcium and 10.6% for phosphorus. Slide 9 This next table shows the crude protein and amino acid composition of the feather meals that we used in this experiment. And as we can see here, crude protein level did not vary much from the feather meal containing no blood to the feather meal that contained blood. However, as we see, the concentration of histidine, which was only 0.7% in the feather meal containing no blood versus 1.27% in the feather meal containing blood. And that gives us 34% of variation. The lysine concentration in feather meal that contained no blood was 1.83%, versus 2.68% in feather meal that contained blood. And the variation in the concentration of lysine was approximately 22%. Methionine concentration was 0.55% when feather meal contained no blood versus 0.66% in the feather meal that contained blood. And the variation was 12%. And tryptophan was also quite variable, with 23% of variation. So from this slide, we can see that there is indeed quite a bit of variation in the concentration of amino acids. Slide 10 For this experiment, we used ten growing barrows with an initial body weight of 24 kg. They were allotted to a 10x10 Latin square design, with ten diets, ten periods, each period consisting of five day adaptation to diet, followed by two days of ileal digesta collection. Slide 11 Ten diets were formulated. The first diet was a soybean meal diet that contained soybean meal as the sole source of crude protein and amino acids. Eight diets were formulated containing feather meal, and in these diets, feather meal was included at 25% of the diet. And we also had 12% of soybean meal. So we had two sources of crude protein and amino acids; we had feather meal and soybean meal. Therefore, we calculated the SID for amino acid and crude protein by the difference procedure. We also formulated the nitrogen-free diet that was used to determine the basal endogenous losses of crude protein and amino acids. Slide 12 Data were analyzed as a 2x4 factorial using mixed procedure of SAS. So, we had feather meal with or without blood, and we had the four sources of feather meal. The model included fixed effects source, blood, and interaction between source and blood, and as random effect, we included pig and period. The PDIFF option was used to separate the means with an alpha level of 0.05. Slide 13 Now, let's take a look at the results. Slide 14 Let me take a moment to set up this graph. We have the standardized ileal digestibility on the Y axis in percent, and on the X axis, we have on the left, feather meal with no blood, and on the right, we have feather meal with blood. For the graphs where we observed an interaction, they will be represented as line graphs; however, when we have only a main effect, we'll be showing these results in bar graphs. So for this first one, we did observe an interaction, and as we can see here, addition of blood to feather meal reduced the SID of crude protein in the feather meal number 1, represented in red, and also feather meal 2, represented in blue. However, adding blood to feather meal number 3 and feather meal number 4 did not affect the SID of crude protein. Slide 15 For the SID of lysine, we also observed an interaction in which adding blood to feather meal number 3 in brown, and number 4 in green, increased the SID of lysine. However, there were no effects of adding blood to feather meal 1 and feather meal 2. Slide 16 For the SID of methionine, we also observed an interaction, and in this case, there was an effect of adding blood to the digestibility of methionine, only for feather meal 1. And so, SID of methionine was decreased from 70% with no blood to 63% with addition of blood. For the other three sources of feather meal, there was no effect of adding blood. Slide 17 Now, for the SID of threonine, there was only a main effect of feather meal. And what we observed here is that the SID of threonine for feather meal 1 in red, and for feather meal 2 in blue, are less than the SID of threonine in feather meal 3 and feather meal 4. Slide 18 For the SID of tryptophan, we observed that there were no differences in the SID of tryptophan between feather meal 1, feather meal 3, and feather meal 4. However, the SID of tryptophan in these three sources was greater than the SID of tryptophan in feather meal 2. Slide 19 Now, let's move on to the discussion. Slide 20 As we can see here, addition of blood increased ash concentration, and that's mainly a result of increasing levels of sodium, chloride, potassium, and iron, which are in high concentrations in blood. And also, adding blood to feather meal increased the concentration of most indispensable amino acids. The SID values determined for soybean meal are in agreement with previous data, and this gives us confidence that the SID values that we determined for feather meal are also accurate because they were calculated by the difference procedure using soybean meal as the other source of crude protein and amino acids in the diet. Slide 21 Some of the variation on amino acid digestibility that we observed here may be explained by the processing techniques using in each source of feather meal. And that involves steam pressure, time of hydrolysis, and also the drying method. And also the addition of blood may have caused some of the interactions that we observed, because addition of blood has been shown to reduce performance of ruminants if added before hydrolysis. And therefore, this may explain some of the differences in amino acid digestibility. Slide 22 The implications of this research are that the lack of standard production between different plant facilities may cause some of the variation in concentration and utilization of crude protein and amino acids in feather meal. And this ultimately limits the use of feather meal by the livestock industry. Therefore, we need to conduct more research to evaluate, for example, the effect of time of blood addition to feather meal -- if added before or after the steam hydrolysis -- and we also need to evaluate the effects of adding different levels of blood to feather meal on the utilization of amino acids and crude protein by pigs. Slide 23 This project was funded by Alabama Agricultural Experiment Station in Auburn, Alabama, and supported by research funds provided to Auburn University by Evonik-Degussa. Ingredients were donated by the Poultry Protein and Fat Council from Georgia. Slide 24 And I encourage you to visit our website at nutrition.ansci.illinois.edu. On this website, you may find more resources about other feed ingredients, and you may click on the tab on top, where it says "Podcasts," where you can listen to this podcast and also other podcasts that are recorded from our group. Thank you very much.