Soybean Meal An Excellent Protein Source for Poultry Feeds Darwin G. Britzman, Ph.D. 1 I. Soybean Meal-An Ideal Protein Source for Poultry Soybeans have been used as a protein/amino acid source in human diets for more than 5000 years. In the early 1900’s soybeans were introduced into the United States primarily for their oil content. It was eventually discovered that the meal by-product was a valuable ingredient for livestock and poultry when it was properly processed. As early as 1917, it was demonstrated that raw soybeans fed to rats were nutritionally inferior to properly heated soybeans. Since that time, soybean meal has become the most important source of protein for poultry and other livestock throughout the world. It is the standard against which other protein sources are compared. It has also become the protein source that determines the price of proteins for livestock feeding throughout the world. Soybean production increased globally by 4,017,141 metric tons per year from 1988 to 1998. In 1998 one hundred fifty seven million metric tons of soybeans were produced in the world. Soybean meal production in 1998 was 101 million metric tons. In the United States soybean meal is the primary source of supplemental protein in poultry, swine and other livestock diets. In 1998 13.28 million metric tons of soybean meal were used in poultry diets. In many of the feed formulas for poultry and swine, soybean meal is the only source of supplemental protein. Poultry consume 52.9% of the soybean meal utilized in the United States. Soybean meal is an excellent choice as a supplemental protein source for poultry for a number of reasons including the following: 1. Soybean meal contains a high level of protein in comparison to other plant protein sources. 44% with hulls 46.5% to 50% without hulls 2. Soybean meal has an excellent profile of essential amino acids as well as other nutrients including potassium and the vitamins choline, folic acid, riboflavin, niacin, pantothenic acid and thiamine. This is shown in Table 1. Table 1: Major Nutrients in Regular and Dehulled Soybean Meal* Regular Meal Dehulled Meal Dry Matter 88.2 88.4 Protein 44.0 47.5 Ether Extract 0.8 1.0 Crude Fiber 7.0 3.9 Methionine 0.62 0.67 Cystine 0.66 0.72 Lysine 2.69 2.90 Tryptophan 0.74 0.74 Threonine 1.72 1.87 Phenylalanine 2.16 2.34 Tyrosine 1.91 1.95 Valine 2.07 2.22 Arginine 3.14 3.48 Histidine 1.17 1.28 Leucine 3.39 3.74 Isoleucine 1.96 2.12 Metabolizable Energy, Kcal./Kg. 2230 2440 Choline, Mg./Kg. 2794 2731 Calcium, % 0.29 0.27 Non Phytate Phos., % 0.27 0.27 Potassium, % 2.00 1.98 *Nutrient Requirements of Poultry, Ninth Revised Edition, 1994 2 Table 2: The Digestibility for Limiting Amino Acids in Poultry Diets* Lysine Methionine Cystine % Blood Meal 86 91 76 Canola Meal 80 90 75 Coconut Meal 58 83 48 Corn Gluten Meal 88 97 86 Cottonseed Meal 67 73 73 Feather Meal 66 76 59 Fish Meal 88 92 73 Meat Meal 79 85 58 Peanut Meal 83 88 78 Poultry by-product Meal 83 88 78 Soybean Meal Dehulled 91 92 82 Sesame Meal 88 94 82 Sunflower Meal Dehulled 84 93 78 * Nutrient Requirements of Poultry, Ninth Revised Edition, 1994 Table 3: A Comparison of Soybean Meal with Other Protein Sources as a Source of Lysine * Protein Source Protein Lysine % % % Plant Proteins Soybean meal 44 2.90 100 Soybean meal 46.5 3.01 104 Soy Protein Concentrate 66 4.20 145 Soy Protein Isolate 92 5.20 179 Alfalfa Meal 17 0.80 28 Canola Meal 38 2.27 27 Corn Gluten Meal 42.1 0.78 58 Sunflower Meal 45.5 1.68 58 Cottonseed Meal 41 1.51 52 Wheat Bran 15 0.56 19 Wheat Gluten, Spray Dried 74 1.30 44 Wheat Middlings 16 0.68 24 Yeast, Brewers Dried 45 3.23 111 Animal Proteins Egg Protein, Spray Dried 48 3.30 114 Fish Meal 60 4.75 164 Blood Meal, Spray Dried 86 8.02 277 Fish Solubles, Dried 54 1.73 60 Porcine Plasma, Spray Dried 70 6.10 210 Meat and Bone Meal 50 2.80 97 Skim Milk, Dried 33 2.54 87 Whey, Dried 12 0.97 33 * Kansas State University Animal Science Department 3 3. The amino acids in soybean meal are highly digestible. A comparison of the digestibility with other protein sources is presented in Table 2. Soybean meal has the highest lysine digestibility (91%) of any on the commonly available protein sources. It also ranks high in methionine, cystine and threonine digestibility. Methionine is the first limiting amino acid in most poultry diets. In addition, the variation in digestibility is less for soybean meal as compared to other oilseed meals. Soybean meal’s relative value as a lysine source compared to other protein supplements is shown in Table 3. 4. Soybean meal has an excellent lysine to protein ratio. This is shown in Table 4. 5. Soybean meal is a palatable source of supplemental protein. It does not adversely impact the palatability of rations for poultry or any other type of livestock. 6. When properly processed, soybean meal contains no toxins or antinutritional factors which affect poultry and other livestock performance. 7. Compared to other plant protein sources, soybean meal has a low content of fiber and a high level of energy. 44% soybean meal contains approximately 7% fiber Dehulled soybean meal contains from 3.3 to 3.5% fiber 8. Soybean meal can serve as the sole source of supplemental protein for all types of poultry at an any stage of growth or production. In most poultry diets soybean meal provides 80% of the dietary amino acids. 9. There is an increasingly abundant supply of soybean meal available to most of the world. 10. Generally soybean meal is a competitively priced source of protein. 11. The quality of soybean meal is relatively consistent compared to other protein sources. II. Soybean Meal Quality Soybeans are relatively consistent in quality. Therefore, the quality of the soybean meal is affected mostly by the processing, handling and storage procedures in producing and transporting the meal. Factors affected include the following: P r o t e i n-the protein content of regular (44%) soybean meal will be affected by the amount of foreign material in the beans or the amount of soy hulls added back to the meal in the processing procedure. Soybeans grown in the northern regions of the United States tend to be slightly lower in protein content. There are also seasonal effects on the protein content of the soybeans. These factors will affect the protein content of dehulled soybean meal and are the reasons for the variances in protein guarantees for dehulled soybean meal. Those guarantees will vary from 46.5% to 50% protein. Table 4: Lysine to Protein Ratios for Various Feed Ingredients Ingredient Crude Protein Lysine Lysine/Protein % % Corn 8.3 0.26 3.13 Sorghum grain 9.2 0.22 2.39 Barley 10.5 0.36 3.42 Soybean meal 47.5 3.02 6.36 Fish meal 62.9 4.81 7.64 Sunflower meal 42.2 0.82 1.94 Cottonseed meal 41.4 1.72 4.15 Sesame meal 42.6 1.01 2.37 Canola meal 35.6 2.08 5.84 Meat meal 54.0 3.07 5.27 Requirement, 14 day old broiler 23.0 1.10 4.78 4 Fat-the oil content of soybean meal is affected by the solvent extraction process. If the extraction process is incomplete, the residual oil will be high. The oil adds to the energy value of the soybean meal, however, if the meal is to be stored for a period of time there is a risk of rancidity with higher oil levels. For that reason, a maximum of 1% oil in the soybean meal is preferred. The minimum guarantee is for 0.1%. Most meals will contain about 0.5%. Fiber-the fiber content of the soybean meal comes primarily from the hulls that are added back to the meal during processing. Foreign materials in the soybean can also add to the fiber content of the meal. Fiber, of course, dilutes the metabolizable energy content of the soybean meal. Maximum fiber guarantees for 44% and dehulled soybean meal are 7 and 3.3 to 3.5%, respectively. Moisture-the maximum moisture in the meal should be 12%. Higher levels of moisture can result in the development of molds within the meal when stored under warm temperature conditions. Higher moisture content also dilutes the nutritional value of the soybean meal. Anti-nutritional factors -raw soybeans contain natural toxins for poultry. Trypsin and chymotrypsin inhibitors-the most problematic anti-nutritional factor is a trypsin inhibitor. The trypsin inhibitors disrupt protein digestion. They affect poultry by increasing the size of the pancreas by 50 to 100%. This has adverse effects on bird growth and egg production. Other toxins include compounds such as phytohaemaglutinins (lectins). These toxins interfer with the normal absorption of pancreatic amylase thereby allowing the enzyme to be quickly eliminated in the feces. These compounds are of less importance than the trypsin inhibitors. Urease is only important in monogastric nutrition as a guide for measuring the adequacy of processing. It is, however, of concern in ruminant feeds that contain urea. The urease will begin to break down the urea when it comes in contact with it. Allergenic factors-Glycinin and Beta-conglycinin reduce nutrient absorption due to their effect on the integrity of the micro-villi of the small intestine. Lipase and lipoxygenase-result in peroxidation and the beany flavor of soybean meal. Hexane-this is the solvent used to extract the oil from the soybeans. Inadequate removal of the hexane after the extraction process will result in liver damage in poultry. Generally excessive hexane is not a problem as processors make every effort to recover it from the meal because of cost and safety considerations. F o r t u n a t e l y, the anti-nutritional compounds in soybeans are heat sensitive and can be destroyed by proper processing (toasting) of the soybeans during the production of the soybean meal. The factors involved in proper processing and methods to evaluate the adequacy of processing will be discussed in section III of this report. Particle size-the meal should be homogenous, free flowing, without coarse particles or excessive fines. Coarse particles will result in poultry being able to select the soybean meal from non pelleted (mash) feed. This will result in unbalanced diets and is not desirable. Extremely fine soybean meal will result in excessive dust during the feed manufacturing process and when the soybean meal is used in meal (mash) feeds. The American Feed Industry Association recommends the following particle sizes: 95-100% through U.S. Standard Sieve No. 10 40-60% through U.S. Standard Sieve No. 20 Maximum of 6.0% through U.S. Sieve No. 80 Flowability-soybean meal is an ingredient that does not flow well in feed mill bins and also tends to cake or bridge. Therefore, anticaking and flow enhancers are often added to the meal. Limestone (calcium carbonate) is frequently used. A maximum of 0.5% is recommended. Other Physical Properties -The American Feed Industry Association has also recommended the following physical properties: The color to be light tan to a light brown The odor to be fresh, not sour, musty or burned The taste to be bland, free of any beany or burned taste The bulk density from 16.4 to 18.2 kg. per cubic foot 5 III. Evaluating Soybean Meal Quality There are a number of methods for evaluating soybean meal quality. These include the following: Visual Observation-representative samples of soybean meal shipments should be examined to determine if there are any obvious contaminates. The meal may have become contaminated with other grains such as corn during shipment and storage. This would, of course, be obvious to the naked eye. If such contamination were great enough it would dilute the nutrient content of the meal. Analyses for Protein, Fiber and Moisture -Since soybean meal is used as a feed ingredient primarily to provide protein and amino acids, it is important to determine that it contains the minimum level of protein that has been guaranteed. Soybean meal is included in feed formulas to provide protein However, soybean meal also provides some energy. A laboratory assay for fiber would determine if the crude fiber levels are below the maximum guarantees. If above guarantee, the energy values for the soybean meal would probably be less than table values. This is also true for moisture. There is also the risk of molding and caking if moisture contents are above 12% and temperature conditions are right. These procedures deal primarily with the quality of the soybeans from which the soybean meal has been produced or the handling of the meal during shipment. The following procedures deal with the processing of the soybeans to produce soybean meal. Heat Processing-it has been well documented that soybean must be heat processed to destroy the antinutritional factors which were discussed in Section II of this report. The degree to which the soybeans are heated is extremely sensitive. If the soybeans are not adequately heated, the antinutritional factors will not be destroyed and the amino acid digestibility is negatively affected. If the soybeans are excessively heated, the antinutritional factors are destroyed and amino acid digestibility is again negatively affected. The effect of inadequate heat processing on the amino acid digestibility of soybean meal is shown in Table 5. The heat processing was accomplished by autoclaving raw soybeans at 121 degrees Centigrade and 15 psi. These data show that the digestibility of lysine, methionine, cystine and threonine was increased as the length of autoclaving increased. This was also true for the other essential amino acids. Table 5: Effect of Under Processing on Amino Acid Digestibility of Raw Soybeans % Digestibility Autoclave Time Minutes Lysine Methionine Cystine Threonine 0 73 65 67 64 9 78 70 70 68 18 87 86 83 82 Table 6: Effect of Over Processing Soybean Meal on Amino Acid Analytical Values and Digestibility % Digestibility Autoclave Time Minutes Lysine Methionine Cystine Threonine 0 91 82 86 84 20 78 69 86 86 40 69 62 83 80 Analytical Values 0 3.27 0.70 0.71 1.89 20 2.95 0.66 0.71 1.92 40 2.76 0.63 0.71 1.87 6 The effect of over processing on soybean meal is shown in Table 6. These data demonstrate that both the analytical values and digestibility of lysine and cystine were reduced by prolonged heating. However, methionine and threonine were not similarly affected. It is known that lysine is affected by the Maillard reaction which binds the free amino groups of the lysine with the carbonyl groups in carbohydrates and reducing sugars and renders the lysine unavailable. The process by which cystine is inactivated by overprocessing is not known. The fact that soybean meal quality is very sensitive to processing procedure makes it very important to have quality evaluation procedures. No doubt the most reliable method of quality evaluation would be to conduct in vivo digestibility feeding trials. However, such trials are time consuming, costly and subject to biological variation. Fortunately, there are laboratory procedures that are more rapid and are useful in evaluating processing adequacy. A brief description of four methods is presented in Table 7. The Urease Assay-this has been the most commonly used laboratory procedure by the commercial feed industry in the United States to determine if the soybean meal has been adequately heated to destroy the antinutritional factors. The enzyme urease is used as a determinate because it is destroyed by heat at a rate similar to the trypsin inhibitors. The urease assay is a simpler and less costly laboratory procedure than is the trypsin inhibitor assay. The urease procedure measures the pH rise in an ammonia solution. For raw soybeans the rise is about 2.0 pH units. The desired pH rise for properly processed soybean meal is between 0.05 to 0.2 units. Some research has shown that a rise of 0.5 pH units is acceptable for broilers, turkeys and swine. Satisfactory results have also been obtained with soybean meal that had a 0 rise in pH units. The urease assay is an effective measure to determine that soybean meal has been adequately heated to destroy the antinutritional factors. However, it does not determine if the soybean meal has been overheated and lysine has been rendered undigestible. KOH Procedure-this procedure was proposed by Araba and Dale at the University of Georgia in 1990. This procedure is used to determine if soybean meal has been overheated. Protein Dispersibility Index (PDI) -this procedure has recently received considerable interest and is being researched by Dr. Carl Parsons at the University of Illinois. Nitrogen Water Solubility Index -this procedure has received very little attention in poultry and animal nutrition. Table 7: Methods for Determining Processing Adequacy of Soybean Meal Urease Assay 1. Mix 0.2 g of SBM with 10 ml. of urea solution 2. Put in 30° C water bath for 30 minutes 3. Determine pH 4. Calculate pH increase (final pH - initial pH) KOH Procedure 1. Mix 1.5 g of SBM with 75 ml of 0.2% KOH for 20 minutes 2. Centrifuge or filter 3. Measure soluble Nitrogen Protein Dispersibility Index (PDI) 1. Mix 8 g of SBM with 150 ml of water 2. Blend at 8500 rpm for 10 minutes 3. Centrifuge or filter and measure soluble Nitrogen Nitrogen Water Solubility Index 1. Mix 5 g of SBM with 20 ml of water 2. Stir at 120 rpm for 120 minutes at 30° C 3. Centrifuge or filter and measure soluble Nitrogen 7 The application of the urease and KOH protein solubility tests is shown in Table 8. As the processing time of raw soybeans was increased from 0 to 18 minutes, the weight gain of chicks increased and the pH change demonstrated that the urease had been destroyed and protein solubility decreased. However, the latter two were very erratic and inconsistent in changing. This experiment demonstrated that the KOH protein solubility assay is not effective in determining that soybean meal has been inadequately heated. Another experiment is shown in Table 9. demonstrating the effect of overprocessing of soybean meal. As processing time increased from 0 to 80 minutes at 120 degrees and 15 psi, chick growth decreased, feed efficiency decreased, pH decreased and protein solubility decreased. The solubility of the protein decreased from 86% at 0 time of autoclaving to 40.8% at 80 minutes of autoclaving. This experiment demonstrated that the urease test is not effective in determining whether or not the soybean meal has been overprocessed. A protein solubility of 70 to 85% is considered acceptable. In an unpublished research trial by Engram and co-workers, three of the methods of processing evaluation were utilized. These results are presented in Table 10. These data show that 18 minutes of autoclaving raw soybeans were required to maximize the growth of chicks. During this time the KOH protein solubility did not change, nor did the urease index. However, the Protein Dispersibility Index (PDI) decreased as autoclaving time increased indicating that this method may be more sensitive to underprocessing than the other two procedures. Table 8: Effect of Autoclaving Raw Soybeans on Chick Growth, Urease Index and KOH Protein Solubility Autoclave Time Chick Growth Urease Index KOH Protein Minutes grams/chick pH Change Solubility % EXPERIMENT # 1 0 98 2.2 87 3 113 2.2 89 6 120 2.1 91 9 124 1.9 91 12 143 0.2 87 15 150 0.0 85 18 151 0.1 76 SBM 158 0.2 77 EXPERIMENT # 2 0 122 2.5 93 6 124 2.4 86 12 152 1.4 90 15 153 0.1 90 18 155 0.0 90 21 156 0.0 74 SBM 156 0.1 74 Table 9: Effect of Autoclaving Soybean Meal on Chick Growth, Urease Index and KOH Protein Solubility Autoclave Time Chick Growth* Feed KOH Protein Urease pH Minutes grams/chick Efficiency Solubility % Change 0 450 a 1.79 86.0 0.03 5 445 a 1.87 76.3 0.02 10 424 a 1.83 74.0 0.00 20 393 b 1.89 65.4 0.00 40 316 c 2.04 48.1 0.00 80 219 d 2.55 40.8 0.00 * To 18 days of age a, b, c, d Are not significantly different 8 The particle size of the soybean meal samples affects protein solubility. This is shown in Table 11. Solubility decreases markedly as particle size of the sample being tested increases. Therefore, it is important that laboratories grind the soybean meal to consistent particle size to obtain repeatable results when utilizing this assay procedure. These experiments demonstrate that there is no one perfect system of evaluating soybean processing adequacy. The protein solubility in KOH test is a method to determine if soybean meal has been overprocessed. It is not useful to determine if the meal in underprocessed. The urease assay is useful to determine if the soybean meal is underprocessed but it is not useful in determining if the meal has been overprocessed. The more recently used protein dispersibility index may be the most sensitive assay. The nitrogen water solubility index has not been frequently used. Perhaps the best approach would be to combine a couple of the procedures. The urease test could be used to determine that the soybean meal had been heated enough to destroy the antinutritional factors. The value should be below 0.5 (below 0.3 preferred). The PDI system would then be used to determine that the soybean meal had not been overprocessed. A PDI value between 35 to 45% would be preferred. As previously mentioned, the primary effect of overheating soybean meal is to render to lysine and cystine unavailable. The negative effect on chick growth can be overcome by the addition of lysine to the damaged soybean meal. The results of experiments demonstrating this are presented in Tables 12 and 13. Based on the data presented in Table 12, the addition of 0.0033% L-lysine for every 10 point decrease in protein solubility will negate the effect of the overprocessing. Fortunately, United States’ commercial soybean processing plants have excellent controls in place for processing soybean meal. Therefore, soybean meal coming from these plants is rarely if ever over or under processed. Table 10: Effect of Autoclaving Raw Soybean Flakes on Chick Growth and Assay Values Autoclave Time Chick Growth KOH Protein Urease pH Protein Dispersibility Minutes grams/chick Solubility % Change Index 0 178 c 97 2.4 76 6 180 c 93 2.2 63 12 189 b 93 2.1 63 18 204 a 94 1.8 47 24 207 a 81 0.2 30 30 205 a 81 0.3 32 36 207 a 78 0.1 24 80 205 a 0.1 SBM 78 0.1 a, b, c, Are not significantly different Table 11: Effect of Particle Size on Protein Solubility of Dehulled Soybean Meal * Mean Particle Size Protein Solubility Micro Meters % 184 90 251 83 299 82 556 79 599 77 707 76 831 74 939 70 * In 0.2% Potassium Hydroxide Solution 9 IV. Utilizing Soybean Meal in Poultry Feeds A comparison of soybean meals from different countries was reported by Dr. Robert Swick in 1995. The results of this comparison are shown in Table 14. Dr. Swick demonstrated that differences do exist between soybean sources in their ability to support broiler growth and feed efficiency. Table 12: Amino Acid Additions on the Performance of Broilers Fed Overheated Soybean Meal Treatment Body Weight grams Feed Efficiency Control (PS 82%) 382 b 1.45 b Overheated (PS 28%) 246 a 1.97 a OH + Lysine 358 b 1.55 b OH + Methionine 253 a 1.98 a OH + Threonine 237 a 1.94 a OH + Lys + Met 355 b 1.66 b OH + Lys + Thr 348 b 1.60 b OH + Lys + Met + Thr 347 b 1.66 b OH + Met + Thr 227 a 1.84 a a, b Means with different superscripts are significantly different at (P<.05) PS = Protein Solubility Table 13. L-Lysine Addition on the Performance of Broilers Fed Over-heated SBM Treatment Body Weight grams Feed Efficiency Control (PS 80.6%) 391 ab 1.41 Control + 0.2% L-Lys 411 ab 1.38 67% PS 54% PS 67% PS 54% PS Overheated 383 b 361 b 1.52 1.55 OH + 0.05% L-Lys 394 ab 381 b 1.44 1.42 OH + 0.10% L-Lys 405 ab 393 ab 1.43 1.50 OH + 0.15% L-Lys 412 a 417 a 1.36 1.40 a, b Means with different superscripts are significantly different at (P<.05) PS = Protein Solubility Table 14. U.S. vs Competitive Soybean Meals (Broiler Trial 0-21 days) Soybean Meal Country of Origin US-1 US-2 China Korea India 1 India 2 Brazil Soybean Meals Crude Protein, % 48.2 44.6 44.0 44.4 45.7 46.4 43.3 Fat % 1.18 1.16 1.05 1.25 1.33 1.15 0.68 TME, kcal/kg 3579 a 3294 ab 3065 b 3496 a 2874 c 3217 ab 3528 a Urease activity 0.03 a 0.08 b 0.12 c 0.04 a 0.15 d 0.08 b 0.05 a Performance N 100 100 100 100 100 100 BW, g 713 a 698 ab 690 b 702 ab 675 b 672 b FI, g 1037 ab 1039 ab 1009 b 1023 ab 1024 ab 1064 a F/G 1.45 a 1.49 ab 1.46 a 1.46 a 1.52 b 1.59 c a, b, c, d : Means in a row that do not have a common superscript are significantly different (P<.05) All rations contained 30% SBM and were isocaloric (3124 kcal/kg), isolysinic and isototal sulfur amino acids. Dudley-Cash (1997); Kang & Swick (1995) [...]... supplemental protein in poultry diets in the United States In broiler feeds, dehulled soybean meal is used In egg production feeds either regular (44%) soybean or dehulled soybean meal is used Example formulas for broiler starter, broiler grower, broiler withdrawal and an egg production layer feeds are presented in the following pages Formulas are presented with 44% and dehulled soybean meal Also presented... shown that fish meal in broiler diets can be replaced by full fat soybean meal in broiler diets The results of this research are shown in Table 15 Dr Swick stated that fish meal can be replaced without affecting broiler performance if it is replaced on an equal nutrient basis Table 15: Replacement of Fish Meal in Broiler Diets with Fullfat Soybean Meal * 5% Fish Meal Fullfat Soybean Meal Gain – KG 1.684... depending on local ingredient prices and availability c Broilers chickens do not have a requirement for crude protein per se There, however, should be sufficient crude protein to ensure an adequate nitrogen supply for synthesis of non essential amino acids Suggested requirements for crude protein are typical of those derived with corn -soybean meal diets, and levels can be reduced somewhat when synthetic... italics represent an estimate based on values obtained for other ages or related species a Final body weight b These are typical dietary energy concentrations for diets based mainly on corn and soybean meal, expressed in kcal ME /kg diet n c Chickens do not have a requirement for crude protein per se There, however, should he sufficient crude protein to ensure an adequate nitrogen supply for synthesis... Laying hens do not have a requirement for crude protein per se However, there should be sufficient crude protein to ensure an adequate supply of nonessential amino acids Suggested requirements for crude protein are typical of those derived with corn -soybean meal diets, and levels can be reduced somewhat when synthetic amino acids are used e Italicized amino acids values for white-egg-laying chickens were... Tables 16, 17, and 18 contain the nutritional suggestions of the U.S Research Council for immature leghorn type chickens, broilers and leghorn type laying hens These were taken from the Nutrient Requirements of Poultry, Ninth Revised Edition, 1994 * Reported at Poultry Science Meeting by Dr Robert Swick and Saksit Srinongkute As previously mentioned in this report, soybean meal is the primary source of... se There, however, should he sufficient crude protein to ensure an adequate nitrogen supply for synthesis of non essential amino acids Suggested requirements for crude protein are typical of those derived with corn -soybean meal diets, and levels can be reduced somewhat when svnthetic amino acids are used d The calcium requirement may be increased when diets contain high levels of phytate phosphorus (Nelson... (90 Percent Dry Matter) 0 to 3 Weeks a 3 to 6 Weeksa 6 to 9 Weeks a Nutrient Unit 3,200b 3,200b 3,200b Protein and amino acids Crude proteinc Arginine Glycine + serine Histidine Isoleucine Leucine Lysine Methionine Methionine + cystine Phenylananine Phenylalanine + tyrosine Proline Threonine Tryptophan Valine % % % % % % % % % % % % % % % 23.00 1.25 1.25 0.35 0.80 1.20 1.10 0.50 0.90 0.72 1.34 0.60 0.80... of feed at 100 g of feed at 110 g of feed 80 a, b 100 a, b 120 a, b per hen daily b per hen daily per hen daily c Protein and amino acids Crude protein d Argininee Histidine Isoleucine Leucine Lvsine Methionine Methionine + Cystine Phenylalanine Phenylalanine - tyrosine Threonine Tryptophan Valine % % % % % % % 18.8 0.88 0.21 0.81 1.03 0.86 0.38 15.0 0.70 0.17 0.65 0.82 0.69 0.30 12.5 0.58 0.14 0.54... 570.00 0.35 0.25 0.15 0.11 470.00 0.30 0.25 0.15 0.11 370.00 0.35 0.25 0.15 0.11 370.00 Unit Protein and amino acids Crude proteinc % Arginine % Glycine + serine % Histidine % Isoleucine % Leucine % Lysine % Methionine % Methionine + Cystine % Phenylalanine % Phenylalanine + tyrosine % Threonine % Tryptophan % Valine % Fat Linoleic acid Macrominerals Calciumd Nonphytate phosphorus Potassium Sodium . Soybean Meal An Excellent Protein Source for Poultry Feeds Darwin G. Britzman, Ph.D. 1 I. Soybean Meal- An Ideal Protein Source for Poultry Soybeans. of the feed formulas for poultry and swine, soybean meal is the only source of supplemental protein. Poultry consume 52.9% of the soybean meal utilized