Loss Of Amino Acids Research Articles

P104. Basal endogenous amino acid losses in the digestive tract are determined by experimental conditions, a meta-analysis

P104. Basal endogenous amino acid losses in the digestive tract are determined by experimental conditions, a meta-analysis

Effects of β-1,3-glucan and ascorbic acid on the nutritional-immune response and antioxidant signaling pathways of live tiger grouper during simulated transport

Transport in water is the most common method for transporting live fish in China, however, transport is a strong stressor. Transport stress could lead to a reduced immune and antioxidant system function of tiger grouper, resulting in sickness and death. Besides, tiger grouper were continuously stressed during transport, which resulted in quality deterioration. It is necessary that find a way to relieve the stress of transportation of tiger grouper. Ascorbic acid is not only a good anti-stress agent, but it is also an effective immunostimulant. β-1,3-glucan is a feed additive that can enhance the immune response of fish. Therefore, this study evaluated the effects of β-1,3-glucan and ascorbic acid on the nutritional-immune response and antioxidant signaling pathways of live tiger grouper during simulated transport. Results indicated that adding β-1,3-glucan and ascorbic acid in transport-water muted the increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity. In addition, β-1,3-glucan and ascorbic acid activated Nrf2 and mediated TOR expression and then up-regulate related mRNA expression of antioxidant and immune enzymes. We concluded that the application of β-1,3-glucan and ascorbic acid inhibit the increase of metabolism enzymes and inflammatory factors and activate immune and antioxidant signaling pathways to relieve oxidant stress, immune response, and apoptosis. Reducing the loss of amino acids provided nutrients to relieve oxidative stress and immune response, which demonstrated immune-nutritional response in live tiger grouper during simulated transport. These results may provide a new solution for alleviating the decline of immune and antioxidant function of tiger grouper caused by transportation stress.

Comparison of endogenous amino acid losses in broilers when offered nitrogen-free diets with differing ratios of dextrose to corn starch

The nitrogen-free diet (NFD) method is widely used to determine the ileal endogenous amino acids (IEAAs) losses in broiler chickens. Starch and dextrose are the main components of NFD, but the effects of their proportion in the NFD on the IEAAs and the digestive physiology of broilers are still unclear. This preliminary study aims to explore the best proportion of glucose and corn starch in NFD to simulate the normal intestinal physiology of broilers, which helps to improve the accuracy of IEAAs determination. For this purpose, 28-day-old broiler chickens were allocated to five treatment groups for a 3-day trial, including a control group and four NFD groups. The ratios of dextrose to corn starch (D/CS) in the four NFD were 1.00, 0.60, 0.33, and 0.14, respectively. Results noted that NFD significantly reduced serum IGF-1, albumin, and uric acid levels compared with the control (P < 0.05), except there was no difference between group D/CS 0.33 and the control for IGF-1. The increased Asp, Thr, Ser, Glu, Gly, Ala, Val, Ile, Leu, His, Tyr, Arg, and Pro contents of IEAAs were detected in broilers fed the NFD with a higher ratio of D/CS (1.00 and 0.60) compared to the lower ratio of D/CS (0.33 and 0.14). Moreover, ileal digestibility of dry matter and activity of digestive enzymes increased as the D/CS elevated (P < 0.001). Further investigation revealed that the number of ileal goblet cells and Mucin-2 expression were higher in the group with D/CS at 1.00 when compared with group D/CS 0.33 and the control (P < 0.05). Microbiota analysis showed that NFD reshaped the gut microbiota, characterized by decreased microbial diversity and lower abundance of Bacteroidetes, and increased Proteobacteria (P < 0.05). Our results indicate that a higher D/CS ratio (1.00 and 0.60) in NFD increases IEAAs by promoting digestive enzymes and mucin secretion. However, the excessive proportion of starch (D/CS = 0.14) in NFD was unsuitable for the chicken to digest. The chickens fed with NFD with the D/CS ratio at 0.33 were closer to the normal digestive physiological state. Thus, the ratio of D/CS in NFD at 0.33 is more appropriate to detect IEAAs of broiler chickens.

Evaluation of the metabolism of PEP06, an endostatin-RGDRGD 30-amino-acid polypeptide and a promising novel drug for targeting tumor cells

PEP06 is a novel endostatin-Arg-Gly-Asp-Arg-Gly-Asp (RGDRGD) 30-amino-acid polypeptide featuring a terminally fused RGDRGD hexapeptide at the N terminus. The active endostatin fragment of PEP06 directly targets tumor cells and exerts an antitumoral effect. However, little is known about the kinetics and degradation products of PEP06 in vitro or in vivo. In this study, we investigated the in vitro metabolic stability of PEP06 after it was incubated with living cells obtained from animals of different species; we further identified the degradation characteristics of its cleavage products. PEP06 underwent rapid enzymatic degradation in multiple types of living cells, and the liver, kidney, and blood play important roles in the metabolism and clearance of the peptides resulting from the molecular degradation of PEP06. We identified metabolites of PEP06 using full-scan mass spectrometry (MS) and tandem MS (MS2), wherein 43 metabolites were characterized and identified as the degradation metabolites from the parent peptide, formed by successive losses of amino acids. The metabolites were C and N terminal truncated products of PEP06. The structures of 11 metabolites (M6, M7, M16, M17, M21, M25, M33, M34, M39, M40, and M42) were further confirmed by comparing the retention times of similar full MS spectrum and MS2 spectrum information with reference standards for the synthesized metabolites. We have demonstrated the metabolic stability of PEP06 in vitro and identified a series of potentially bioactive downstream metabolites of PEP06, which can support further drug research.

Effects of extrusion on ileal and total tract nutrient and energy digestibility of untoasted soybean meal in weanling pigs

This study evaluated the nutrient and energy digestibility of untoasted soybean meal (USM) extruded at three different temperatures, compared to toasted soybean meal (SBM), in weaned piglets. Forty crossbred barrows (25-d-old and 7.69 ± 0.89 kg BW) were allotted to a N-free diet or to four test diets in a randomized complete block design with 8 replications per treatment. The N-free diet was used to determine endogenous losses of amino acids (AA), and test diets contained 30% of each test ingredient as the only source of protein and AA: untoasted soybean meal extruded at 86 °C (USM86), 120 °C (USM120) or 149 °C (USM149) or with SBM, as a control diet. Titanium dioxide was added to the diets as an indigestible marker. After a 5 d adaptation period, feces were collected over a 5 d period and samples of ileal digesta were collected after piglets euthanasia. The apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), ether extract (EE), crude protein (CP), neutral detergent fiber (aNDF) and acid detergent fiber (ADF), and apparent (AID) and standardized (SID) ileal digestibility of AA, and their respective digestible values were evaluated. Analysis of variance was performed and the means were compared by Tukey when P < 0.05. Increasing extrusion temperature decreased concentrations of soybean trypsin inhibitors. Untoasted soybean meal extruded at 86 °C showed lower (P < 0.05) ATTD of DM (7–11%), GE (3–4%), and CP (10–13%) compared to SBM, USM120 and USM149, which did not differ. The ATTD of EE of SBM was 17–19% higher (P < 0.05) than that of USM86 and USM120, which were similar to each other and greater (P < 0.05) than that of USM149. Extrusion of USM at 86 oC was insufficient to inactivate anti-nutritional factors and reduced (P < 0.05) AID and SID of CP and AA by 25–29% and 27–31%, respectively, compared to SBM, USM120 and USM149, which were mostly similar. Soybean meal extruded at 120 and 149 °C presented a similar nutritional value to toasted soybean meal.

Digestibility of amino acids in fish meal and blood-derived protein sources fed to pigs.

ObjectiveAn experiment was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in fish meal (FM) and blood-derived protein sources including spray-dried porcine plasma (SDPP), porcine red blood cells (PRBC), and blood meal (BM) fed to growing pigs.MethodsTen barrows (mean initial body weight of 22.1±1.54 kg) surgically fitted with T-cannulas at the distal ileum were allotted to a duplicated 5×4 incomplete Latin square design with 5 experimental diets and 4 periods. Four experimental diets were prepared to contain FM, SDPP, PRBC, or BM as the sole source of nitrogen. A nitrogen-free diet was prepared and included to estimate the basal ileal endogenous losses of AA. For the 7-day experimental period, pigs were fed for 5 days as adaptation, and ileal digesta samples were collected for 9 hours on days 6 and 7.ResultsThe SID of crude protein in BM (48.0%) was less (p<0.05) than in FM, SDPP, and PRBC (83.4%, 83.9%, and 87.3%, respectively). Pigs fed the diet containing BM had less (p<0.05) SID of AA, except isoleucine and proline, than those fed the diet containing FM, SDPP, or PRBC. Among FM, SDPP, and PRBC, there was no difference in the SID of crude protein and all AA, except isoleucine. The SID of isoleucine in PRBC and BM (62.7% and 48.3%, respectively) was less (p<0.05) than in FM and SDPP (88.0% and 84.9%, respectively). The SID of lysine in FM, SDPP, PRBC, and BM was 85.4%, 84.9%, 89.7%, and 51.9%, respectively.ConclusionThe SID of most AA was not different among FM, SDPP, and PRBC, but BM had lower SID of most AA than FM, SDPP, and PRBC.

Standardized ileal digestibility of amino acids of protein sources associated with exogenous enzymes for broilers.

ObjectiveTwo experiments were conducted to evaluate the effect of enzyme complex (EC) on the standardized ileal digestibility (SID) of amino acids (AA) in corn gluten meal (60%) (CGM), soy protein concentrate (SPC), dried bovine plasma (DBP), and poultry offal meal (POM). Experiments I and II were conducted with broilers in the pre-starter (1 to 7 days of age) and starter (1 to 21 days of age) phases, respectively.MethodsThe treatments consisted of a protein-free diet (PFD) containing feedstuffs either supplemented with EC (xylanase, amylase, and protease) or not. In Experiment I, a total of 360 one-day-old male Cobb-500 broiler chicks were randomly housed in 45 pens, resulting in five replicates with eight birds each, totalizing eight treatments and one PFD group. In Experiment II a total of 270 one-day-old male Cobb-500 broiler chicks were randomly housed in 45 pens, resulting in five replicates with six birds each, totalizing eight treatments and one PFD group. The PFD groups were used to assess the endogenous AA losses. The birds were slaughtered to collect the ileal content.ResultsIn the pre-starter phase, the SID of arginine, branched chain-aminoacids, glycine, serine, aspartate, and glutamic acid increased with EC addition. The EC improved the SID of arginine and glutamic acid of CGM; the SID of valine and cystine of SPC; the SID of leucine, glycine, and aspartate of POM and the SID of isoleucine of DBP. In the starter phase, the SID of isoleucine, phenylalanine and glycine increased in EC-supplemented diets. The EC improved the SID of isoleucine of DBP; the SID of phenylalanine of CGM and POM. The SID of AA of SPC was not influenced by the EC.ConclusionThe addition of an EC to broiler pre-starter and starter diets is efficient in increasing the SID of AA on SPC, POM, and DBP.

Sweet taste perception in mice is blunted by PTBP1-regulated skipping of Tas1r2 exon 4.

Taste perception, initiated by activation of taste receptors in taste bud cells, is crucial for regulating nutrient intake. Genetic polymorphisms in taste receptor genes cannot fully explain the wide individual variations of taste sensitivity. Alternative splicing (AS) is a ubiquitous posttranscriptional mode of gene regulation that enriches the functional diversity of proteins. Here, we report the identification of a novel splicing variant of sweet taste receptor gene Tas1r2 (Tas1r2_∆e4) in mouse taste buds and the mechanism by which it diminishes sweet taste responses in vitro and in vivo. Skipping of Tas1r2 exon 4 in Tas1r2_∆e4 led to loss of amino acids in the extracellular Venus flytrap domain, and the truncated isoform reduced the response of sweet taste receptors (STRs) to all sweet compounds tested by generating nonfunctional T1R2/T1R3 STR heterodimers. The splicing factor PTBP1 (polypyrimidine tract-binding protein 1) promoted Tas1r2_∆e4 generation through binding to a polypyrimidine-rich splicing silencer in Tas1r2 exon 4, thus decreasing STR function and sweet taste perception in mice. Taken together, these data reveal the existence of a regulated AS event in Tas1r2 expression and its effect on sweet taste perception, providing a novel mechanism for modulating taste sensitivity at the posttranscriptional level.

Comparison of Methods for Estimating Basal Endogenous Losses of Amino Acids; Additivity of Amino Acids Digestibility in Corn and Soybean Meal for Broilers

Comparison of Methods for Estimating Basal Endogenous Losses of Amino Acids; Additivity of Amino Acids Digestibility in Corn and Soybean Meal for Broilers

High Amylose Amylopectin Ratios in Nitrogen-Free Diet Decrease the Ileal Endogenous Amino Acids Losses of Broiler Chickens

High Amylose Amylopectin Ratios in Nitrogen-Free Diet Decrease the Ileal Endogenous Amino Acids Losses of Broiler Chickens

Effects of extrusion on ileal and total tract digestibility of nutrients and energy in soybean for weanling pigs

This study evaluated the ileal and total tract digestibility of nutrients and energy in soybean extruded at three different conditions, compared to deactivated soybean (DS), in newly weaned piglets. Forty crossbred barrows (28 d old and 7.64 ± 0.88 kg body weight) were allotted to 5 dietary treatments with 8 replications per treatment. The diets consisted of an N-free diet, to determine endogenous losses of amino acids (AA), and 4 diets containing 30% of test ingredients as the only source of protein and AA: soybean extruded at 82 °C (SB82), 122 °C (SB122) and 137 °C (SB137), and DS, which was used as a control. The DS was produced by heating the whole raw soybean, from 63 °C to 107 °C under pressure. Titanium dioxide was added to the diets as an indigestible marker. After a 5 d adaptation period, partial feces collection was performed over 5 d and samples of ileal digesta were collected after piglets euthanasia. The apparent total tract digestibility of dry matter, gross energy (GE), crude protein (CP), neutral detergent fiber and acid detergent fiber, and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA were evaluated. Analysis of variance was performed and the means compared by Tukey test when P < 0.05. The extrusion of soybean at 122 °C and 137 °C was effective in reducing trypsin inhibitors content, and promoted adequate nutrient and energy digestibility of soybean in piglets. These effects could be observed as the AID of Lys and Trp, and SID of Lys of SB122 and SB137 were greater (P < 0.05) than those of SB82 and DS. The AID and SID of CP and remaining AA were similar among SB122, SB137 and DS, but greater (P < 0.05) than those of SB82. In addition, the ATTD of GE of SB122 was 3–4% greater (P < 0.05) than those of DS and SB82, showing an important effect of extrusion on energy use by pigs. Thus, extrusion of soybean at 122 °C is recommended and SB122 is a feed ingredient with greater nutritional value than DS or SB82 for young pigs.

Chemical Stability of Proteins in Foods: Oxidation and the Maillard Reaction.

Protein is a major nutrient present in foods along with carbohydrates and lipids. Food proteins undergo a wide range of modifications during food production, processing, and storage. In this review, we discuss two major reactions, oxidation and the Maillard reaction, involved in chemical modifications of food proteins. Protein oxidation in foods is initiated by metal-, enzyme-, or light-induced processes. Food protein oxidation results in the loss of thiol groups and the formation of protein carbonyls and specific oxidation products of cysteine, tyrosine, tryptophan, phenylalanine, and methionine residues, such as disulfides, dityrosine, kynurenine, m-tyrosine, and methionine sulfoxide. The Maillard reaction involves the reaction of nucleophilic amino acid residues with reducing sugars, which yields numerous heterogeneous compounds such as α-dicarbonyls, furans, Strecker aldehydes, advanced glycation end-products, and melanoidins. Both protein oxidation and the Maillard reaction result in the loss of essential amino acids but may positively or negatively impact food structure and flavor.

Influence of Age on the Standardized Ileal Amino Acid Digestibility of Corn and Barley in Broilers.

Simple SummaryEfficient amino acid (AA) utilization in broilers is crucial concerning the accuracy of feed formulation, economy of diet and minimizing nitrogenous pollution in the environment. A range of factors (ingredient type, age, sex, feed form and bird type) can affect the AA digestion in poultry. The first week of broiler life is considered the most critical period while chicks source nutrition from residual yolk. Dynamic changes are noted in the digestive tract development, secretion and activity of protein digestive enzymes during the first few weeks in broiler. Limited data exist on the age effect on AA digestibility in broilers, and the results are paradoxical. The aim of the present study was to investigate the influence of age on the standardized ileal digestibility coefficients (SIDCs) of AAs in corn and barley from hatching to the end of the broiler growth cycle (day 42). Based on the results, the age influence on AA digestibility is grain- and AA-dependent. The pattern of the age effect on the SIDC AA in corn was not consistent. In the case of barley, the SIDC AA increased with advancing age.The aim of this study was to determine the standardized ileal digestibility coefficients (SIDCs) of nitrogen (N) and amino acids (AAs) in corn and barley at six different ages (days 7, 14, 21, 28, 35 and 42) of broilers using the direct method. The apparent AA digestibility coefficients were corrected using age-appropriate basal endogenous AA losses. No age effect (p > 0.05) was noted for the SIDC of N in corn. The average SIDC of indispensable AAs (IAAs) and total AAs (TAAs) was influenced in a quadratic manner (p < 0.05) with the values being higher at day 7 that decreased at day 14, increased and plateaued between days 21 and 35 and dropped again at day 42. The average SIDC of dispensable AAs (DAAs) was influenced linearly (p < 0.05). In barley, the SIDC of N and average IAAs, DAAs and TAAs was affected (quadratic; p < 0.001) by age. The digestibility increased from day 7 to 21 and then plateaued up to day 42. The present findings confirm that the SIDC of AA in corn and barley are influenced by broiler age and that the age effect on AA digestibility may need to be considered for precise feed formulation.

Effect of macromolecular crowding on protein oxidation: Consequences on the rate, extent and oxidation pathways

Biological systems are heterogeneous and crowded environments. Such packed milieus are expected to modulate reactions both inside and outside the cell, including protein oxidation. In this work, we explored the effect of macromolecular crowding on the rate and extent of oxidation of Trp and Tyr, in free amino acids, peptides and proteins. These species were chosen as they are readily oxidized and contribute to damage propagation. Dextran was employed as an inert crowding agent, as this polymer decreases the fraction of volume available to other (macro)molecules. Kinetic analysis demonstrated that dextran enhanced the rate of oxidation of free Trp, and peptide Trp, elicited by AAPH-derived peroxyl radicals. For free Trp, the rates of oxidation were 15.0 ± 2.1 and 30.5 ± 3.4 μM min−1 without and with dextran (60 mg mL−1) respectively. Significant increases were also detected for peptide-incorporated Trp. Dextran increased the extent of Trp consumption (up to 2-fold) and induced short chain reactions. In contrast, Tyr oxidation was not affected by the presence of dextran. Studies on proteins, using SDS-PAGE and LC-MS, indicated that oxidation was also affected by crowding, with enhanced amino acid loss (45% for casein), chain reactions and altered extents of oligomer formation. The overall effects of dextran-mediated crowding were however dependent on the protein structure. Overall, these data indicate that molecular crowding, as commonly encountered in biological systems affect the rates, and extents of oxidation, and particularly of Trp residues, illustrating the importance of appropriate choice of in vitro systems to study biological oxidations.

Influence of Domestic Cooking on Quality, Nutrients and Bioactive Substances of Undaria pinnatifida.

Undaria pinnatifida (UP) is a brown algae commonly consumed as food in Asian countries. The purpose of this study was to compare the effects of different domestic cooking methods (i.e., air frying (AF), microwaving, and high temperature and pressure (HTP) cooking) on the nutritional and bioactive substances in UP, as well as on UP color and texture, in order to identify methods to retain beneficial components better. In this study, microwave treatment resulted in better retention of color, polysaccharide (4.17 ± 0.07 mg glucose equivalents (GE)/g dry weight (dw) ), total phenol content (TPC) (1.50 ± 0.0062 mg gallic acid equivalents (GAE)/g dw) as well as chlorophyll a (18.18 ± 0.41 mg/g fresh weight (fw) ) and fucoxanthin (281.78 ± 17.06 μg/g dw). HTP treatment increased the TPC of UP (1.69 ± 0.0075 mg GAE/g dw), and AF treatment resulted in a lower loss of total amino acids (2.14 ± 0.15%). Overall, microwave cooking appeared to be the best among the three in producing cooked UP with high quality. This study provided a useful guideline in selection of cooking for UP which could retain more health-beneficial substances and yield products with better eating qualities to improve human diet.

Biosensor Design Towards Monitoring of Amino Acids for Critical Care Patients

Recently, attention to the amounts of amino acids in critical care patients’ blood have risen, emphasizing the loss of amino acids during renal replacement therapy. Recent clinical studies demonstrate that the majority of continuous renal replacement therapy patients experience a significant loss in total amino acid levels reaching up to 14–22 g per session. These alterations result in negative nitrogen balance, which is independently associated with longer stay in intensive care unit, prolonged overall hospital stay and increased rates of morbidity and mortality. Furthermore, critical care patients are known to have deficits in some of specific amino acids (glutamate, glutamine, lysine). These imbalances are further exacerbated by the renal replacement therapy, adding up to the promotion of the systemic inflammatory response syndrome, engaged in various pathologies and resulting in a worse clinical outcome of the patients. Therefore, it is highly important to develop a biosensing technology with capabilities to measure total and, in some cases, specific amino acids.In this work we present a biosensing platform capable of fast quantification of total amino acids' concentration in real media, in a physiological concentration range (5–500 µmol/l). There are many reports in literature concerning amino acid biosensors, however, no electrochemical biosensor is commercially available, and amino acids today are measured by using slow and expensive colorimetric detections kits or chromatographic analyzers. Thus, the key novelty point of this work is the development of the electrochemical amino acids biosensing platform, which is expected to operate in clinical conditions. In addition, we have developed a new solution for the developed system such as new enzymatic membranes, electroconductive surfaces as well as specific measurements algorithms (Figure 1). All the solutions combined together provide a sensitive biosensor for the detection of amino acids, and could be applied for patients undergoing renal replacement therapy (Figure 1 A). Figure 1

228 Standardized Ileal Digestibility of Partially Defatted Black Soldier Fly Larvae Meal in Growing Pig Diets

Abstract New ingredients need to be characterized both chemically and in vivo, then compared to commonly-used protein ingredients before they can be considered for use in feeds. The objective of the present study was to determine the standardized ileal digestibility (SID, %) of amino acids (AA) of partially defatted black soldier fly larvae meal (BSFLM) (49.7% CP; 14.4% crude fat as fed). Subsequently, these results were compared to the SID AA of common protein ingredients in swine feed, fish meal (FM) and soybean meal (SBM) (NRC 2012), and to published full-fat (FF) BSFLM SID values. Six ileal-cannulated barrows (18.03 ± 0.67 kg BW) were used in a 2x2 Latin square design and fed either a nitrogen-free diet (NFD) or BSFLM-containing diet over two 11-d experimental periods. In each period, barrows were adapted for 7 days to the diet and ileal digesta collection was conducted on day 10 and 11 for 8h per day. Basal endogenous AA losses (EAAL) were calculated from pigs fed the NFD and as expected, the ileal AA content were significantly higher for pigs fed the BSFLM diet than NFD (P &amp;lt; 0.05). SID for AA were then calculated based on the obtained EAAL values following Stein et al., 2007. For essential AA, the SID of BSFLM were all above 82%, the highest being Arg (93.76%), followed by Met (91.32%), and Phe (89.80%). The SID of essential AA were on average 5.0% higher in BSFLM than FM, but 2.7% lower than SBM. When compared to the FF BSFLM, SID of essential AA of BSFLM were 1–5% higher, except for Phe and Thr. These results suggest that partially defatted BSFLM is a promising alternative protein ingredient in growing pig diets, which has a more digestible AA profile than FM, only slightly lower than SBM, and comparable to the FF BSFLM.

Contribution of purified soybean trypsin inhibitor and exogenous protease to endogenous amino acid losses and mineral digestibility

The primary objective of the current study was to evaluate the impact of trypsin inhibitor (TI) and exogenous protease supplementation on endogenous loss of amino acids (AA) in broiler chickens. A total of 384 Cobb-500 broiler chicks were allocated to 4 nitrogen-free diets, each with 8 replicate cages and 12 birds per replicate. The diets were arranged as a 2 × 2 factorial with factors being dietary TI (0 or 8,000 TIU/g) and exogenous protease (0 or 15,000 PROT/kg). Desired dietary TI concentration was achieved by addition of commercially available, purified soybean TI. There was no effect of TI or exogenous protease or their interaction on growth performance of birds. However, the endogenous loss of nitrogen (N) and all AA increased (P < 0.05) due to dietary TI concentration except for Cys. The increase in endogenous AA due to TI ranged from 17% for Thr to 52.2% for Trp. Exogenous protease had no effect on endogenous loss of N and all AA. There was no effect of TI or exogenous protease or their interaction on the AID of P, however AID of Ca, Fe, Mg, Mn, and Cu was reduced (P < 0.05) due to dietary TI. The AID of Cu (P < 0.01) and K (P < 0.05) improved with exogenous protease supplementation. Significant interactions (P < 0.05) between exogenous protease and TI existed for Zn, Mg, Cu, and Na. The concentration (g/kg DM intake) of crude mucin and sialic acid increased (P < 0.05) with increased dietary TI. Decreased trypsin (P < 0.001) and increased chymotrypsin (P < 0.001) activity in the pancreas were observed as a result of exogenous protease supplementation. In conclusion, the current study showed that TI increases the endogenous loss of AA and reduced the digestibility of minerals in broiler chickens. Furthermore, exogenous protease did not affect endogenous AA flow, irrespective of added purified dietary TI.

An investigation into the influence of age on the standardized amino acid digestibility of wheat and sorghum in broilers

Standardized ileal digestibility coefficients (SIDC) of nitrogen (N) and amino acids (AA) in wheat and sorghum at 6 different ages (d 7, 14, 21, 28, 35, and 42) of broilers were determined. Two assay diets were formulated to contain 93.8% of each grain as the sole source of AA in the diet. Titanium dioxide (0.5%) was added as an indigestible marker. Each assay diet was fed to 6 replicate cages housing 14 (d 7), 12 (d 14), 10 (d 21), 8 (d 28), 8 (d 35), and 6 (d 42) birds per cage for 4 d prior to ileal digesta collection. The apparent ileal digestibility coefficients (AIDC) were standardized by using the age-appropriate basal endogenous AA losses. In the case of wheat, AIDC of N and all AA increased (linear or quadratic, P < 0.05 to 0.001) with advancing age. No age effect was noticed on the SIDC of N, average of indispensable (IAA) and dispensable AA (DAA), though the average of total AA (TAA) tended (linear, P = 0.09) to increase as birds grew older. In sorghum, the AIDC of N, average of IAA and DAA were unaffected (P > 0.05) by age. The SIDC of N, average SIDC of IAA, DAA and TAA were higher at d 7, reduced at d 14 and then plateaued. Among the IAA, the SIDC of Arg, His, Ile, Leu, Lys, Thr, Val, and the SIDC of all individual DAA (except Cys) decreased with age (linear or quadratic, P < 0.05 to 0.001) with higher values at d 7. The higher SIDC values determined at d 7 were due to higher EAA losses during wk 1. The results showed that broiler age influences AA digestibility and this may need be considered in practical feed formulations. The age effect is variable depending on the grain type and specific AA.

Exudative glutamine losses contribute to high needs after burn injury.

BackgroundBurnpatients characteristically have increased energy, glucose, and protein requirements. Glutamine supplementation is strongly recommended during early‐phase treatment and is associated with improved immunity, wound healing, and reduced mortality. This study evaluated if early burn exudative losses might contribute to higher supplementation needs.MethodsPatients admitted to the burn intensive care unit (ICU) had exudate collection from tight bandages applied to arms or legs during the first week (exudate aliquot twice daily). Seven amino acids (alanine, arginine, cystEine, glutamine, leucine, lysine, and methionine) were quantified by liquid chromatography–mass spectrometry. Descriptive analysis of all results is provided as median and interquartile range or in value ranges.ResultsEleven patients aged 19–77 years, presenting with burns on 18%–70% of the body surface, with a median simplified acute physiology score II of 33 (range, 16–56) were included during the study period. The highest amino acid losses were observed during the first 3 days with an important interpatient and intrapatient variability. Glutamine and alanine losses were highest, followed by leucine and lysine in all patients; amino acid exudate concentrations were in the range of normal plasma concentrations and were stable over time. Total glutamine losses were correlated to the burned surface (r2 = 0.552, P = .012), but not to enteral glutamine supplements.ConclusionsThe study shows significant exudative losses during early‐stage burn recovery and particularly for glutamine and alanine. Glutamine loss generally decreased with wound closure, the subsequent decline of exudation, and the evolving size of burn surfaces.