Amino Acid

Determination of TMEn, standardized amino acid digestibility, and phosphorus digestibility in soybean expellers produced from a new variety soybeans fed to chickens

Cristobal, M., J. Blair, P. L. Utterback, H. H. Stein, and C. M. Parsons. 2023. Determination of TMEn, standardized amino acid digestibility, and phosphorus digestibility in soybean expellers produced from a new variety soybeans fed to chickens. Poultry Sci. 102 (E-suppl. 1): 37. Link to abstract.

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Digestible indispensable amino acid scores (DIAAS) for egg and plant proteins

Fanelli, Natalia dos Santos, Juliana Carolina Florencio Ravagnani Martins, and Hans Henrik Stein. 2023. Digestible indispensable amino acid scores (DIAAS) for egg and plant proteins. International Symposium Dietary Protein for Human Health. Utrecht, The Netherlands Sep 2023. Pag 74. Link to Abstract.

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Both pelleting and reducing particle size of corn increase net energy and digestibility of amino acids and fat in corn-soybean meal diets fed to growing pigs

Pelleting and reducing particle size of grains often improve nutrient digestibility by pigs. Pelleting may also reduce particle size of grains, and it is not known if improvements in nutrient digestibility obtained by reducing the particle size of grain and improvements obtained by pelleting are additive or if there are interactions between particle size reduction and pelleting. Therefore, two experiments were conducted to test the hypothesis that particle size reduction and pelleting, separately or in combination, increase the apparent ileal digestibility (AID) of starch, the standardized ileal digestibility (SID) of amino acids (AA), N balance, apparent total tract digestibility (ATTD) of gross energy (GE), fiber, and fat, and net energy (NE) in corn-soybean meal diets fed to growing pigs.

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Amino acid digestibility in soybean meal and crystalline amino acid based diets fed to growing pigs

Soybean meal (SBM) is the major source of amino acids (AA) and energy in diets for swine throughout the world. However, due to the emergence of feed-grade crystalline AA, it is estimated that SBM usage by pigs has been reduced by at least 35% over the last 25 years. Reduction on concentration of SBM and increasing the use of crystalline AA in diets may impact the digestibility of crude protein (CP) and AA. Therefore, the objective of this experiment was to test the hypothesis that diets containing corn, SBM, and crystalline AA have greater AA digestibility compared with corn and SBM diets.

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Metabolizable energy and amino acid digestibility by growing pigs may be reduced if excessive heat is applied during drying of corn

Corn is harvested at a high moisture level, and thus must be dried to less than 15% moisture to ensure safe storage. Improvements to reduce the energy consumption of the dryers have been implemented, especially by increasing the inlet air temperature. However, overheating may have a negative impact on the stability of nutrients, especially amino acids (AA), because Maillard reactions may occur if heat and moisture are applied to feed ingredients. Consequently, Maillard reactions result in a decrease in the concentration and digestibility of AA, and it is possible that energy digestibility is also reduced. Therefore, the objective of these experiments was to test the hypothesis that both the temperature used in drying and the time that heat is applied will affect the standardized ileal digestibility (SID) of AA, and concentration of digestible energy (DE) and metabolizable energy (ME) in corn fed to growing pigs.

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Apparent ileal digestibility of amino acids by pigs is not affected by increasing dietary calcium from deficient to excess concentrations, but phosphorus digestibility is reduced

Lee, Su A, H. H. Stein. 2022. Apparent ileal digestibility of amino acids by pigs is not affected by increasing dietary calcium from deficient to excess concentrations, but phosphorus digestibility is reduced. Animal Feed Science and Technology 292 (2022) 115436. doi.org/10.1016/j.anifeedsci.2022.115436. Link to full text.

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Isoquinoline alkaloids impact intestinal health and function of weanling pigs fed diets formulated below amino acid requirements

Rundle, C., V. Artuso-Ponte, and H. H. Stein. 2022. Isoquinoline alkaloids impact intestinal health and function of weanling pigs fed diets formulated below amino acid requirements. 15th International Symposium on Digestive Physiology of Pigs. Animal - Science Proceedings 13(Issue 2): 176. Link to Abstract.

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The amino acid digestibility and digestible indispensable amino acid score for rapeseed protein isolate increases after moderate heating resulting in a protein quality similar to whey protein isolate

Rapeseed is the second most produced oilseed in the world after soybean, and after the oil is extracted, a protein-rich meal is the resulting byproduct containing greater concentrations of sulfur amino acids (AA; i.e., Met and Cys) and Lys compared with legumes and cereal grains. Rapeseed proteins have great potential as a high-quality plant-based protein for humans due to their well-balanced AA profile, high metabolic utilization of protein, a protein digestibility corrected amino acid score (PDCAAS) similar to soy and milk proteins, and easily separable antinutritional factors. However, to our knowledge, digestible indispensable amino acid score (DIAAS) has not been determined for rapeseed protein isolate and the level of processing required to concentrate rapeseed into a protein isolate warrants further evaluation of its protein quality. Therefore, this experiment was conducted to test the hypothesis that heat treatment of rapeseed protein isolate will increase the digestibility of AA by growing pigs and result in a DIAAS that is comparable to soy and animal protein isolates.

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Nutrient digestibility and endogenous protein losses in the foregut and small intestine of weaned dairy calves fed calf starters with conventional or enzyme-treated soybean meal

Ansia, I., H. H. Stein, C. Brøkner, C. A. Hayes, and J. K. Drackley. 2021. Nutrient digestibility and endogenous protein losses in the foregut and small intestine of weaned dairy calves fed calf starters with conventional or enzyme-treated soybean meal. J. Dairy Sci. 104:2979–2995. doi.org/10.3168/jds.2020-18776.

Review of current data for digestible indispensable amino acid scores (DIAAS) determined for human foods

Bailey, H. M., and H. H. Stein. 2020. Review of current data for digestible indispensable amino acid scores (DIAAS) determined for human foods. J. American Oil Chemists’ Society. 97(Suppl.1): 16. doi:10.1002/aocs.12427. Link to the abstract.

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Effects of a novel E. coli phytase expressed in Pseudomonas fluorescens on growth, bone mineralization, and nutrient digestibility in pigs fed corn–soybean meal diets

Ren, Ping, Laia Blavi, Caroline González-Vega, Yanhong Liu, Deana Hancock, Mercedes Vazquez-Añón, Ferdinando N. Almeida, and Hans H. Stein. 2020. Effects of a novel E. coli phytase expressed in Pseudomonas fluorescens on growth, bone mineralization, and nutrient digestibility in pigs fed corn–soybean meal diets. Transl. Anim. Sci.

Ileal digestibility of amino acids in a new source of high-protein distillers dried grains with solubles fed to growing pigs

Acosta Medellin, Jessica P., Su A Lee, Hans H. Stein. 2020. Ileal digestibility of amino acids in a new source of high-protein distillers dried grains with solubles fed to growing pigs. J. Anim. Sci. 98(Suppl. 3): 148. doi.org/10.1093/jas/skaa054.260. (Abstr.). Link to abstract.

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Pork Products Have Digestible Indispensable Amino Acid Scores (DIAAS) That Are Greater Than 100 When Determined in Pigs, but Processing Does Not Always Increase DIAAS

Bailey, Hannah M., John K. Mathai, Eric P. Berg, and Hans H. Stein. 2020. Pork Products Have Digestible Indispensable Amino Acid Scores (DIAAS) That Are Greater Than 100 When Determined in Pigs, but Processing Does Not Always Increase DIAAS. The Journal of Nutrition. Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions. doi: https://doi.org/10.1093/jn/nxz284.

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Transitioning from the Protein Digestibility Corrected Amino Acid Score (PDCAAS) to the Digestible Indispensable Amino Acid Score (DIAAS) to evaluate protein quality of human foods.

Bailey, H. M., and H. H. Stein. 2019. Transitioning from the Protein Digestibility Corrected Amino Acid Score (PDCAAS) to the Digestible Indispensable Amino Acid Score (DIAAS) to evaluate protein quality of human foods. Inform Magazine, 30:22-24. June, 2019. Doi., 10.21748/inform.06.2019.22. Link to full text.

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Pork products have digestible indispensable amino acid scores that are greater than 100, but processing does not always increase amino acid scores

Pork is the most widely consumed animal meat in the world accounting for approximately 40% of the total global meat intake. Pork almost always undergoes some degree of processing prior to consumption. Consequently, thermal processing induces modification to the 3-dimentional structure of proteins, which may lead to increased digestibility of amino acids (AA).

Protein quality is evaluated in human foods by the digestible indispensable amino acid score (DIAAS) methodology, which can be described as the digestibility of individual dietary indispensable AA (IAA) compared with the same IAA in 1 of the 3 reference protein patterns established by the Food and Agriculture Organization of the United Nations (FAO). Values for DIAAS of bovine meat cooked by various techniques have been determined, yet to our knowledge, there are no reported DIAAS values for pork products and the IAA digestibility of pork after processing has not been reported.

Therefore, the objective for the present work was to determine DIAAS values for pork products, and to test the hypothesis that processing may increase protein quality.

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Effects of dietary leucine concentration on branched-chain amino acid metabolism in growing pigs

Leucine, Val, and Ile are categorized as the branched-chain AA (BCAA) because of the structural similarity of their side chains. All 3 BCAA share the enzymes that are involved in the first 2 steps of their catabolic pathway. The first step is a transamination step catalyzed by BCAA transaminase (BCAT) and producing branched-chain α-keto acids (BCKA). The second step is an irreversible degradation step catalyzed by branched-chain α-keto acid dehydrogenase (BCKDH). In the second step, Leu has been considered a key regulator as its BCKA metabolite (α-keto isocaproate) stimulates activation of the BCKDH complex in the liver. When excess Leu in diets is offered to pigs, degradation of all 3 BCAA may increase because of increased activity of BCAT and BCKDH. Leucine and Trp are both categorized as large neutral AA, and they share a common uptake pathway across the blood-brain barrier. Therefore, it is possible that excessive Leu may result in reduced Trp uptake into the brain due to competition for transporters, resulting in reduced serotonin synthesis.

 

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