Structural Engineering of Carbon Host Derived from Organic Pigment toward Physicochemically Confinement and Efficient Conversion of Polysulfide for Lithium-Sulfur Batteries.

Lithium-Sulfur Batteries (LSBs) have attracted significant attention as promising next-generation energy storage systems. However, the commercial viability of LSBs have been hindered due to lithium polysulfides (LiPSs) shuttle effect, resulting in poor cycling stability and low sulfur utilization. To address this issue, herein, the study prepares a sulfur host consisting of micro/mesopore-enriched activated carbonaceous materials with ultrahigh surface area using organic pigment via facile one-step activation. By varying the proportion of chemical agent, the pore size and volume of the activated carbonaceous materials are manipulated and their capabilities on the mitigation of LiPSs shuttle effect are investigated. Through the electrochemical measurements and spectroscopic analysis, it is verified that structural engineering of carbon hosts plays a pivotal role in effective physical confinement of LiPSs, leading to the mitigation of LiPSs shuttle effect and sulfur utilization. Additionally, nitrogen and oxygen-containing functional groups originated from PR show electrocatalytic activation sites, facilitating LiPSs conversion kinetics. The approach can reveal that rational design of carbon microstructures can improve trapping and suppression of LiPSs and shuttle effect, enhancing electrochemical performance of LSBs.

Effects of Mycotoxin-Sequestering Agents on Growth Performance and Nutrient Utilization of Growing Pigs Fed Deoxynivalenol-Contaminated Diets.

The objective of this study was to investigate the effects of supplemental mycotoxin-sequestering agents on growth performance and nutrient utilization in growing pigs fed deoxynivalenol (DON)-contaminated diets. Twelve barrows with an initial body weight of 35.5 kg (standard deviation = 1.3) were assigned to six dietary treatments in a replicated 6 × 5 incomplete Latin square design. Five experimental diets consisted of an uncontaminated diet (PC), a DON-contaminated diet at 6.89 mg/kg (NC), NC + bentonite 0.5%, NC + yeast cell wall 0.5%, and NC + a mixture product 0.5% which consisted of enzymes, microorganisms, minerals, and plant extracts. Pigs had ad libitum access to the five diets. In the last group, the PC diet was restrictedly provided to pigs at the quantity of feed consumption of the NC group. Average daily gain, average daily feed intake, and gain:feed were not affected by supplemental mycotoxin-sequestering agents except for the mixed product that tended to improve (p = 0.064) gain:feed in pigs fed DON-contaminated diets. The apparent total tract digestibility (ATTD) of dry matter was not affected by DON contamination or by supplemental mycotoxin-sequestering agents, whereas the ATTD of Ca was decreased (p = 0.032) by supplemental yeast cell wall in pigs fed DON-contaminated diets. The ATTD of P was greater (p = 0.042) in pigs fed the NC diet compared with the pigs fed the restricted amount of the PC diet. In conclusion, bentonite and yeast cell wall did not affect growth performance of pigs fed DON-contaminated diets, but a supplemental mixed product consisting of enzymes, microorganisms, minerals, and plant extracts partially alleviated the negative effects of dietary DON on the gain:feed of pigs. Calcium digestibility was decreased by supplemental yeast cell wall in pigs fed DON-contaminated diets. Based on the present work, the use of a mixed product consisting of enzymes, microorganisms, minerals, and plant extracts is suggested, and the reduction of Ca digestibility by yeast cell wall needs to be considered in diet formulations.

Enhanced Ca2+-channeling complex formation at the ER-mitochondria interface underlies the pathogenesis of alcohol-associated liver disease.

Ca2+ overload-induced mitochondrial dysfunction is considered as a major contributing factor in the pathogenesis of alcohol-associated liver disease (ALD). However, the initiating factors that drive mitochondrial Ca2+ accumulation in ALD remain elusive. Here, we demonstrate that an aberrant increase in hepatic GRP75-mediated mitochondria-associated ER membrane (MAM) Ca2+-channeling (MCC) complex formation promotes mitochondrial dysfunction in vitro and in male mouse model of ALD. Unbiased transcriptomic analysis reveals PDK4 as a prominently inducible MAM kinase in ALD. Analysis of human ALD cohorts further corroborate these findings. Additional mass spectrometry analysis unveils GRP75 as a downstream phosphorylation target of PDK4. Conversely, non-phosphorylatable GRP75 mutation or genetic ablation of PDK4 prevents alcohol-induced MCC complex formation and subsequent mitochondrial Ca2+ accumulation and dysfunction. Finally, ectopic induction of MAM formation reverses the protective effect of PDK4 deficiency in alcohol-induced liver injury. Together, our study defines a mediatory role of PDK4 in promoting mitochondrial dysfunction in ALD.

Pyrolyzed Organic Pigment as Efficient Surface-Dominated Alkali-Ion Storage Anodes.

Carbonaceous materials have attracted as prospective anodes for rechargeable alkali-ion batteries. In this study, C.I. Pigment Violet 19 (PV19) was utilized as a carbon precursor to fabricate the anodes for alkali-ion batteries. During thermal treatment, the generation of gases from the PV19 precursor triggered a structural rearrangement into nitrogen- and oxygen-containing porous microstructures. The anode materials fabricated from pyrolyzed PV19 at 600 °C (PV19-600) showed outstanding rate performance and stable cycling behavior (554 mAh g-1 over 900 cycles at a current density of 1.0 A g-1) in lithium-ion batteries (LIBs). In addition, PV19-600 anodes exhibited reasonable rate capability and good cycling behavior (200 mAh g-1 after 200 cycles at 0.1 A g-1) in sodium-ion batteries (SIBs). To define the enhanced electrochemical performance of PV19-600 anodes, spectroscopic analyses were employed to reveal the storage mechanism and kinetics of the alkali ions in pyrolyzed PV19 anodes. A surface-dominant process in nitrogen- and oxygen-containing porous structures was found to promote the alkali-ion storage ability of the battery.

Inhibition of Pyruvate Dehydrogenase Kinase 4 in CD4+ T Cells Ameliorates Intestinal Inflammation.

BACKGROUND & AIMS: Despite recent evidence supporting the metabolic plasticity of CD4+ T cells, it is uncertain whether the metabolic checkpoint pyruvate dehydrogenase kinase (PDK) in T cells plays a role in the pathogenesis of colitis. METHODS: To investigate the role of PDK4 in colitis, we used dextran sulfate sodium (DSS)-induced colitis and T-cell transfer colitis models based on mice with constitutive knockout (KO) or CD4+ T-cell-specific KO of PDK4 (Pdk4fl/flCD4Cre). The effect of PDK4 deletion on T-cell activation was also studied in vitro. Furthermore, we examined the effects of a pharmacologic inhibitor of PDK4 on colitis. RESULTS: Expression of PDK4 increased during colitis development in a DSS-induced colitis model. Phosphorylated PDHE1α, a substrate of PDK4, accumulated in CD4+ T cells in the lamina propria of patients with inflammatory bowel disease. Both constitutive KO and CD4+ T-cell-specific deletion of PDK4 delayed DSS-induced colitis. Adoptive transfer of PDK4-deficient CD4+ T cells attenuated murine colitis, and PDK4 deficiency resulted in decreased activation of CD4+ T cells and attenuated aerobic glycolysis. Mechanistically, there were fewer endoplasmic reticulum-mitochondria contact sites, which are responsible for interorganelle calcium transfer, in PDK4-deficient CD4+ T cells. Consistent with this, GM-10395, a novel inhibitor of PDK4, suppressed T-cell activation by reducing endoplasmic reticulum-mitochondria calcium transfer, thereby ameliorating murine colitis. CONCLUSIONS: PDK4 deletion from CD4+ T cells mitigates colitis by metabolic and calcium signaling modulation, suggesting PDK4 as a potential therapeutic target for IBD.

Correlation between Pitch Impregnation Pressure and Pore Sizes of Graphite Block.

This study aimed to investigate the effect of impregnation pressure on the decrease in porosity of impregnated bulk graphite. The correlation between pitch impregnation behavior and the pore sizes of the bulk graphite block was studied to determine the optimal impregnation pressure. The densities and porosities of the bulk graphite before and after pitch impregnation under various pressures between 10 and 50 bar were evaluated based on the Archimedes method and a mercury porosimeter. The density increased rates increased by 1.93-2.44%, whereas the impregnation rate calculated from the rate of open porosity decreased by 15.15-24.48%. The density increase rate and impregnation rate were significantly high when the impregnation pressures were 40 and 50 bar. Compared with impregnation pressures of 10, 20, and 30 bar, the minimum impregnatable pore sizes with impregnation pressures of 40 and 50 bar were 30-39 and 24-31 nm, respectively. The mercury intrusion porosimeter analysis results demonstrated that the pressure-sensitive pore sizes of the graphite blocks were in the range of 100-4500 nm. Furthermore, the ink-bottle-type pores in this range contributed predominantly to the effect of impregnation under pressure, given that the pitch-impregnated-into-ink-bottle-type pores were difficult to elute during carbonization.

Effects of dietary leucine and tryptophan on serotonin metabolism and growth performance of growing pigs.

An experiment was conducted to test the hypothesis that increased dietary Trp is needed in high-Leu diets for growing pigs to prevent a drop in plasma serotonin and hypothalamic serotonin concentrations and to maintain growth performance of animals. A total of 144 growing pigs (initial weight: 28.2 ± 1.9 kg) were assigned to 9 treatments in a randomized complete block design with 2 blocks, 2 pigs per pen, and 8 replicate pens per treatment. The 9 diets were formulated in a 3 × 3 factorial with 3 levels of dietary Leu (101%, 200%, or 299% standardized ileal digestible [SID] Leu:Lys), and 3 levels of dietary Trp (18%, 23%, or 28% SID Trp:Lys). A basal diet that met requirements for SID Leu and SID Trp was formulated and 8 additional diets were formulated by adding crystalline L-Leu and (or) L-Trp to the basal diet. Individual pig weights were recorded at the beginning of the experiment and at the conclusion of the 21-d experiment. On the last day of the experiment, 1 pig per pen was sacrificed, and blood and hypothalamus samples were collected to measure plasma urea N, plasma serotonin, and hypothalamic serotonin concentrations. Results indicated that increasing dietary Trp increased (P < 0.05) hypothalamic serotonin, whereas increases (P < 0.05) in average daily gain (ADG) and average daily feed intake (ADFI) were observed only in pigs fed diets containing excess Leu. Increasing dietary Leu reduced (P < 0.05) ADG, ADFI, and hypothalamic serotonin. However, the increase in ADG and ADFI caused by dietary Trp was greater if 299% SID Leu:Lys was provided than if 101% SID Leu:Lys was provided (interaction, P < 0.05). Plasma Leu concentration was positively affected by dietary Leu and negatively affected by dietary Trp, but the negative effect of Trp was greater if 299% SID Leu:Lys was provided than if 101% SID Leu:Lys was provided (interaction, P < 0.05). Plasma concentration of Trp was positively affected by increased dietary Trp and increased dietary Leu, but the increase in plasma concentration of Trp was greater if Leu level was at 101% SID Leu:Lys ratio than at 299% SID Leu:Lys ratio (interaction, P < 0.05). In conclusion, increased dietary Leu reduced ADG, ADFI, and hypothalamic serotonin concentration, and influenced metabolism of several indispensable amino acids, but Trp supplementation partly overcame the negative effect of excess Leu. This demonstrates the importance of Trp in regulation of hypothalamic serotonin, and therefore, feed intake of pigs.

Comparative Study on Toughening Effect of PTS and PTK in Various Epoxy Resins.

This study investigated the toughening effect of in situ polytriazoleketone (PTK) and polytriazolesulfone (PTS) toughening agent when applied to various epoxy resins, such as diglycidyl ether of bisphenol A (DGEBA), diglycidyl ether of bisphenol F (DGEBF), and triglycidyl p-aminophenol (TGAP) with 3,3'-diaminodiphenylsulfone as a curing agent. The fracture toughness, tensile properties, and thermal properties of the prepared epoxy samples were evaluated and compared. When PTK was mixed with DGEBF, the fracture toughness was improved by 27% with 8.6% increased tensile strength compared to the untoughened DGEBF. When PTS was mixed with TGAP, the fracture toughness was improved by 51% without decreasing tensile properties compared to the untoughened TGAP. However, when PTK or PTS was mixed with other epoxy resins, the fracture toughness decreased or improved with decreasing tensile properties. This is attributed to the poor miscibility between the solid-state monomer of PTK (4,4'-bis(propynyloxy)benzophenone (PBP)) or PTS (4,4'-sulfonylbis(propynyloxy)benzene (SPB)) and the epoxy resin, resulting in the polymerization of low molecular weight PTK or PTS in epoxy resin. Therefore, the toughening effect of PTK or PTS can be maximized by the appropriate selection of epoxy resin based on the miscibility between PBP or SPB and the resin.

Facile Fabric Detoxification Treatment Method Using Microwave and Polyethyleneimine Against Nerve Gas Agents.

Generally, detoxification fabrics are defined as fabrics that remove or inhibit the production of toxic compounds, especially chemical warfare agents such as nerve gas agents. They are usually prepared using a complicated and time-consuming method. This study suggests a facile treatment method for preparing detoxification fabrics against nerve gas agents using polyethyleneimine and microwave curing. The detoxification properties of polyethyleneimine and microwave-treated polypropylene nonwoven fabric were evaluated using diisopropylfluoro-phosphate, which is a nerve agent simulant. The treated polypropylene fabric decontaminated 53.6% of diisopropylfluorophosphate (DFP) in 2 h at 32 °C, and the half-life of DFP on the surface of the treated fabric was 122 min. The result indicates that the treated fabric can act as a basic organocatalyst for the DFP hydrolysis and has a shorter half-life owing to the large number of amine groups. Therefore, the facile treatment method has the potential for use in the preparation of detoxification fabrics.

Effects on nitrogen balance and metabolism of branched-chain amino acids by growing pigs of supplementing isoleucine and valine to diets with adequate or excess concentrations of dietary leucine.

Diets based on high levels of corn protein have elevated concentrations of Leu, which may negatively affect N retention in pigs. An experiment was, therefore, conducted to test the hypothesis that Ile and Val supplementation may overcome the detrimental effects of excess dietary Leu on N balance and metabolism of branched-chain amino acids (BCAA) in growing pigs. A total of 144 barrows (initial body weight: 28.5 kg) were housed in metabolism crates and randomly assigned to 1 of 18 dietary treatments. The basal diet contained 0.98% standardized ileal digestible (SID) Lys and had SID Leu, Val, and Ile ratios to SID Lys of 100%, 60%, and 43%, respectively. Crystalline l-Leu (0% or 2.0%), l-Ile (0%, 0.1%, or 0.2%), and l-Val (0%, 0.1%, or 0.2%) were added to the basal diet resulting in a total of 18 dietary treatments that were arranged in a 2 × 3 × 3 factorial. Urine and fecal samples were collected for 5 d after 7 d of adaptation. Blood, skeletal muscle, and liver samples were collected at the conclusion of the experiment. There were no three-way interactions among the main effects. Excess Leu in diets reduced (P < 0.05) N retention and biological value of protein and increased (P < 0.001) plasma urea N (PUN), but PUN was reduced (P < 0.05) as dietary Val increased. Concentrations of Leu in the liver were greater (P < 0.001) in pigs fed excess Leu diets than in pigs fed adequate Leu diets, but concentrations of BCAA in muscle were greater (P < 0.05) in pigs fed low-Leu diets. Increasing dietary Ile increased (P < 0.001) plasma-free Ile and plasma concentration of the Ile metabolite, α-keto-ß-methylvalerate, but the increase was greater in diets without excess Leu than in diets with excess Leu (interaction, P < 0.001). Plasma concentrations of Val and the Val metabolite α-keto isovalerate increased (P < 0.001) with increasing dietary Val in diets with adequate Leu, but not in diets with excess Leu (interaction, P < 0.001). Increasing dietary Leu increased (P < 0.001) plasma-free Leu and plasma concentration of the Leu metabolite, α-keto isocaproate (KIC). In contrast, increased dietary Val reduced (P < 0.05) the plasma concentration of KIC. In conclusion, excess dietary Leu reduced N retention and increased PUN in growing pigs, but Val supplementation to excess Leu diets may increase the efficiency of amino acid utilization for protein synthesis as indicated by reduced PUN.

Detoxification Properties of Guanidinylated Chitosan Against Chemical Warfare Agents and Its Application to Military Protective Clothing.

This study investigates the detoxification properties of guanidinylated chitosan against chemical warfare agents and its application to the preparation of military protective clothing. Guanidinylated chitosan was synthesized by chitosan guanidinylation with cyanamide. The detoxification properties of the guanidinylated chitosan were then evaluated using a chemical warfare agent simulant, called diisopropylfluorophosphate (DFP). Cotton fabric was treated with 1 wt.% of guanidinylated chitosan in acetic acid and water solution using the simple and conventional textile treatment method of pad-dry-cure. The detoxification properties of the guanidinylated chitosan-treated cotton fabric were evaluated to investigate the application of guanidinylated chitosan to the preparation of military protective clothing. Subsequently, 71.3% of DFP was hydrolyzed to non-hazardous diisopropylhydrogenphosphate (DHP) in 2 h because of the base organocatalytic activity of 0.02 g guanidinylated chitosan itself. Moreover, 60.1% of DFP was hydrolyzed by the catalytic activity of the guanidinylated chitosan-treated cotton fabric, which contained only 0.0002 g of guanidinylated chitosan. This result shows that the guanidinylated chitosan itself has detoxification properties for hydrolyzing DFP to DHP, and its detoxification properties can be more efficient when applied to cotton fabric because it showed 84.3% of the detoxification properties with only 1 wt.% of guanidinylated chitosan. For the first time, this study shows that guanidinylated chitosan has considerable detoxification properties and can be used as an agent to prepare protective clothing.

Excess dietary leucine in diets for growing pigs reduces growth performance, biological value of protein, protein retention, and serotonin synthesis1.

An experiment was conducted to test the hypothesis that excess dietary Leu affects metabolism of branched-chain amino acids (BCAA) in growing pigs. Forty barrows (initial body weight [BW]: 30.0 ± 2.7 kg) were housed individually in metabolism crates and allotted to 5 dietary treatments (8 replicates per treatment) in a randomized complete block design. The 5 diets were based on identical quantities of corn, soybean meal, wheat, and barley and designed to contain 100%, 150%, 200%, 250%, or 300% of the requirement for standardized ileal digestible Leu. Initial and final (day 15) BW of pigs were recorded. Daily feed consumption was also recorded. Urine and fecal samples were collected for 5 d following 7 d of adaptation to the diets. At the end of the experiment, blood and tissue samples were collected to analyze plasma urea N (PUN), plasma and hypothalamic serotonin, tissue BCAA, serum and tissue branched-chain α-keto acids, and messenger ribonucleic acid abundance of genes involved in BCAA metabolism. Results indicated that acid detergent fiber, average daily feed intake, and gain-to-feed ratio decreased (linear, P < 0.05) as dietary Leu increased. A trend (linear, P = 0.082) for decreased N retention and decreased (linear, P < 0.05) biological value of dietary protein was also observed, and PUN increased (linear, P < 0.05) as dietary Leu increased. A quadratic reduction (P < 0.05) in plasma serotonin and a linear reduction (P < 0.05) in hypothalamic serotonin were observed with increasing dietary Leu. Concentrations of BCAA in liver increased (linear, P < 0.001), whereas concentrations of BCAA in skeletal muscle decreased (linear, P < 0.05) as dietary Leu increased. Concentration of α-ketoisovalerate was reduced (linear and quadratic, P < 0.001) in liver, skeletal muscle, and serum, and α-keto-ß-methylvalerate was reduced (linear, P < 0.001; quadratic, P < 0.001) in skeletal muscle and serum. In contrast, α-keto isocaproate increased (linear, P < 0.05) in liver and skeletal muscle and also in serum (linear and quadratic, P < 0.001) with increasing dietary Leu. Expression of mitochondrial BCAA transaminase and of the E1α subunit of branched-chain α-keto acid dehydrogenase increased (linear, P < 0.05) in skeletal muscle as dietary Leu increased. In conclusion, excess dietary Leu impaired growth performance and nitrogen retention, which is likely a result of increased catabolism of Ile and Val, which in turn reduces availability of these amino acids resulting in reduced protein retention, and excess dietary Leu also reduced hypothalamic serotonin synthesis.

PDK4 Deficiency Suppresses Hepatic Glucagon Signaling by Decreasing cAMP Levels.

In fasting or diabetes, gluconeogenic genes are transcriptionally activated by glucagon stimulation of the cAMP-protein kinase A (PKA)-CREB signaling pathway. Previous work showed pyruvate dehydrogenase kinase (PDK) inhibition in skeletal muscle increases pyruvate oxidation, which limits the availability of gluconeogenic substrates in the liver. However, this study found upregulation of hepatic PDK4 promoted glucagon-mediated expression of gluconeogenic genes, whereas knockdown or inhibition of hepatic PDK4 caused the opposite effect on gluconeogenic gene expression and decreased hepatic glucose production. Mechanistically, PDK4 deficiency decreased ATP levels, thus increasing phosphorylated AMPK (p-AMPK), which increased p-AMPK-sensitive phosphorylation of cyclic nucleotide phosphodiesterase 4B (p-PDE4B). This reduced cAMP levels and consequently p-CREB. Metabolic flux analysis showed that the reduction in ATP was a consequence of a diminished rate of fatty acid oxidation (FAO). However, overexpression of PDK4 increased FAO and increased ATP levels, which decreased p-AMPK and p-PDE4B and allowed greater accumulation of cAMP and p-CREB. The latter were abrogated by the FAO inhibitor etomoxir, suggesting a critical role for PDK4 in FAO stimulation and the regulation of cAMP levels. This finding strengthens the possibility of PDK4 as a target against diabetes.

Non-antibiotic feed additives in diets for pigs: A review.

A number of feed additives are marketed to assist in boosting the pigs' immune system, regulate gut microbiota, and reduce negative impacts of weaning and other environmental challenges. The most commonly used feed additives include acidifiers, zinc and copper, prebiotics, direct-fed microbials, yeast products, nucleotides, and plant extracts. Inclusion of pharmacological levels of zinc and copper, certain acidifiers, and several plant extracts have been reported to result in improved pig performance or improved immune function of pigs. It is also possible that use of prebiotics, direct-fed microbials, yeast, and nucleotides may have positive impacts on pig performance, but results have been less consistent and there is a need for more research in this area.

Standardized total tract digestibility of phosphorus in various inorganic phosphates fed to growing pigs.

An experiment was conducted to determine the standardized total tract digestibility (STTD) of phosphorus (P) in five sources of inorganic phosphate fed to growing pigs, including dicalcium phosphate (DCP), monodicalcium phosphate (MDCP), monocalcium phosphate (MCP), tricalcium phosphate (TCP) and monosodium phosphate (MSP, reagent grade). Six barrows (42.4 ± 1.1 kg) individually housed in metabolism crates were allotted to a 6 × 6 Latin square design with six dietary treatments and six periods. Each experimental period consisted of a 4 day adaptation period and a 5 day collection period. The five experimental diets contained 0.24 to 0.34% of P from each inorganic phosphate as a sole source of P. A P-free diet was also prepared to estimate the basal endogenous loss of P. The STTD of P in MSP (94.9%) was not different from the STTD of P in MCP (93.0%), but was greater (P < 0.05) than that in DCP, MDCP and TCP (87.0, 86.5 and 71.3%, respectively). In conclusion, digestibility of P in reagent-grade MSP was greater than that in feed-grade inorganic phosphates such as DCP, MDCP and TCP, and digestibility of P in DCP and MDCP was greater than that in the TCP.

A dynamic human motion: coordination analysis.

This article is concerned with the generic structure of the motion coordination system resulting from the application of the method of virtual holonomic constraints (VHCs) to the problem of the generation and robust execution of a dynamic humanlike motion by a humanoid robot. The motion coordination developed using VHCs is based on a motion generator equation, which is a scalar nonlinear differential equation of second order. It can be considered equivalent in function to a central pattern generator in living organisms. The relative time evolution of the degrees of freedom of a humanoid robot during a typical motion are specified by a set of coordination functions that uniquely define the overall pattern of the motion. This is comparable to a hypothesis on the existence of motion patterns in biomechanics. A robust control is derived based on a transverse linearization along the configuration manifold defined by the coordination functions. It is shown that the derived coordination and control architecture possesses excellent robustness properties. The analysis is performed on an example of a real human motion recorded in test experiments.

Dietary acidifiers in weanling pig diets: a review / Acidificantes dietarios para cerdos recién destetados: revisión / Dietas acidificadas em suínos desmamados: uma revisão

The objective of the present review is to provide an overview on the effects of the addition of acidifiers to nursery pig diets. Researchers have proposed that dietary acidifiers decrease pH in the stomach and the lower gastrointestinal tract (GIT) of weanling pigs, and thus, protect the host from pathogenic invasion and proliferation and improve nutrient digestion. These benefits may subsequently result in improved growth performance of weanling pigs. In experiments on nursery pigs, dietary acidifiers decreased stomach pH at least to a small extent, but had little influence on the pH of the lower GIT. Studies found no observable changes in microbial populations upon providing weanling pigs with dietary acidifiers, but they found a slight reduction in lactobacilli or lactic acid-producing bacteria throughout the GIT. Dietary acidifiers improved protein digestion in many cases despite variable results regarding the digestibility of amino acids and improved growth performance. Such positive responses were more apparent during the first or second week of experiments than the later stages. However, growth responses were inconsistent among different sources and varying inclusion rates of acidifiers. Information on the dietary acidifiers’ mode of action is quite limited, and large variations exist in results regarding the effects of dietary acidifiers. Based on the present review, the benefit of dietary acidifiers for nursery pigs is not entirely convincing. Further research is required to clarify the acidifiers’ mode of action and its association with subsequent growth performance in weanling pigs.

El objetivo de esta revisión es ofrecer una visión general sobre los efectos de la adición de acidificantes orgánicos en la dieta de cerdos destetos. Se ha propuesto que los acidificantes dietarios reducen el pH en el estómago y tracto gastrointestinal (TGI) de los cerdos recién destetados, y por lo tanto protegen al huésped de la invasión y proliferación de patógenos, al tiempo que mejoran la digestión de nutrientes. Estos beneficios podrían resultar en una mejora del crecimiento de dichos animales. En experimentos con cerdos destetados, los acidificantes dietarios han mostrado que pueden disminuir el pH del estómago, al menos en pequeña medida, pero han tenido poca influencia en el pH del tracto gastrointestinal posterior. Algunos estudios no encontraron cambios observables en las poblaciones microbianas al ofrecer acidificantes en la dieta a estos animales, pero se reporta una ligera reducción de los lactobacilos o bacterias lácticas productoras de ácido en todo el tracto gastrointestinal. En muchos casos, los acidificantes parecen mejorar la digestión proteica, a pesar de ofrecer resultados variables con respecto a la digestibilidad de los aminoácidos y mejora del crecimiento. Tales respuestas positivas parecen ser más evidentes durante la primera o segunda semana de los experimentos que en etapas posteriores. Sin embargo, la respuesta en crecimiento ha sido inconsistente respecto a diferentes fuentes y niveles de inclusión de acidificantes. La información sobre el modo de acción de los acidificantes dietarios es bastante limitada y existen grandes variaciones en los resultados respecto a sus efectos. De acuerdo con esta revisión, el beneficio potencial de los acidificantes dietarios en cerdos destetados no está del todo justificado. Se requiere investigación adicional para aclarar su modo de acción y su relación con el crecimiento de los cerdos recién destetados.

O objetivo desta revisão é fornecer uma visão geral dos efeitos da adição de acidificantes orgânicos na dieta de leitões desmamados. Tem sido proposto que a dieta acidificante reduz o pH do estômago e do trato gastrointestinal (TGI) de leitões desmamados, e assim proteger o hospedeiro da invasão e proliferação de patogênicos, melhorando a digestão dos nutrientes. Estes podem resultar em um maior crescimento destes animais. Em experimentos com suínos desmamados, a acidificação da dieta têm sido mostrados para diminuir o pH do estômago, pelo menos em pequena medida, mas tiveram pouca influência sobre o pH do trato gastrointestinal posterior. Alguns estudos não encontraram alterações observáveis em populações microbianas ao oferecer acidificantes na dieta, mas tem-se reportado uma ligeira redução de lactobacilos ou bactérias lácticas produtoras de ácido em tudo o trato gastrointestinal. Em muitos casos, os acidificantes parecem melhorar a digestão de proteínas, apesar de oferecer resultados variáveis com respeito à digestibilidade dos aminoácidos e melhora o crescimento. ais respostas positivas parecem ser mais evidentes durante a primeira ou segunda. No entanto, a resposta de crescimento tem sido inconsistente com relação a diferentes fontes e níveis de inclusão de acidificantes. A Informação sobre o modo de ação dos acidificantes na dieta é bastante limitado e existem grandes variações nos resultados sobre seus efeitos. De acordo com essa análise, o benefício potencial de alimentar leitões desmamados com acidificantes não é inteiramente justificado. Mais pesquisas são necessárias para esclarecer seu modo de ação e sua relação com o crescimento de leitões desmamados.