Dietary ethylenediamine dihydroiodide mitigated Escherichia coli O78-induced immune and intestinal damage of ducks via suppression of NF-κB signal.

This study investigated the effect of Ethylenediamine dihydroiodide (EDDI) on growth performance, immune function and intestinal health of meat ducks challenged with Avian pathogenic Escherichia coli (APEC). A total of 360 one-day-old Cherry Valley ducks with similar body weight were randomly allocated to 6 treatments (6 floor cages, 10 birds/cage). A 3 × 2 factor design was used with 3 dietary iodine levels (0, 8, 16 mg/kg in the form EDDI and whether APEC was challenged or not at 7-day-old ducks. The feeding period lasted for 20 d. The results showed that the addition of EDDI reduced APEC-induced decrease of the 20-d weight loss of meat ducks (P < 0.05), and alleviated the inflammatory response of liver tissue induced by APEC challenge in meat ducks. In terms of immune function, EDDI supplementation reduced the immune organ index and increased the immune cell count of meat ducks, reduced the level of endotoxins in the serum of meat ducks (P < 0.05), as well as inhibited the expression levels of liver and spleen inflammatory factors and TLR signaling pathway related genes induced by APEC (P < 0.05). In terms of intestinal health, EDDI inhibited APEC-induced decreases in ZO-3 genes expression and increases in IL-1ß and TNF-α expression, increased relative abundance of beneficial bacteria in the cecum and content of metabolites. Pearson correlation analysis showed that there was a significant correlation between liver inflammatory factors and TLR4 signaling pathway genes, and there might be a significant correlation between intestinal microbial flora and other physiological indexes of meat ducks, which indicated that EDDI could reduce the damage to immune function and intestinal health caused by APEC challenge through regulating the structure of intestinal flora. Collectively, our findings suggest that the EDDI can promote growth performance, improve immune function and the intestinal barrier in APEC-challenged meat ducks, which may be related to the suppression of NF-κB signal.

Effects of Dietary Glutamine Supplementation on the Modulation of Microbiota and Th17/Treg Immune Response Signaling Pathway in Piglets after Lipopolysaccharide Challenge.

BACKGROUND: Glutamine (Gln) has an important effect on the growth performance and immune function of piglets. However, the effect of Gln on intestinal immunity in piglets through modulating the signaling pathways of the helper T cells 17 (Th17)/regulatory T cells (Treg) immune response has not been reported. OBJECTIVE: This study aimed to determine the effect of Gln on piglet growth performance and immune stress response and its mechanism in piglets. METHODS: Twenty-four weaned piglets were randomly assigned to 4 treatments with 6 replicates each, using a 2 × 2 factorial arrangement: diet (basal diet or 1% Gln diet) and immunological challenge [saline or lipopolysaccharide (LPS)]. After 21 d, half of the piglets on the basal diet and 1% Gln diet received the intraperitoneal injection of LPS and the other half received the same volume of normal saline. RESULTS: The results showed that Gln increased average daily feed intake and average daily weight gain in comparison with the control group (P < 0.05). Dietary Gln increased the villus height, villus height-to-crypt depth ratio, and the abundance of Bacteroidetes, Lactobacillus sp., and Ruminococcus sp. while reducing the abundance of Firmicutes, Clostridium sensu stricto 1 sp., and Terrisporobacter sp. (P < 0.05). Furthermore, Gln increased the concentration of short-chain fatty acids in the colon and the expression of genes of interleukin (IL)-10, transforming growth factor-beta-1, forkhead box P3 while downregulating the expression of genes of IL-6, IL-8, IL-1ß, tumor necrosis factor-α, IL-17A, IL-21, signal transducer and activator of transcription 3, and rar-related orphan receptor c in ileum (P < 0.05). Correlation analysis demonstrated a strong association between colonic microbiota, short-chain fatty acids, and ileal inflammatory cytokines. CONCLUSIONS: These results suggest that dietary Gln could improve growth performance and attenuate LPS-challenged intestinal inflammation by modulating microbiota and the Th17/Treg immune response signaling pathway in piglets.

Alpha-ketoglutaric acid attenuates oxidative stress and modulates mitochondrial dynamics and autophagy of spleen in a piglet model of lipopolysaccharide-induced sepsis.

Alpha-ketoglutaric acid (2-ketoglutaric acid or 2-oxoglutaric acid, AKG), a crucial intermediate in the tricarboxylic acid cycle, is pivotal in animal antioxidative process. The purpose of this study was to investigate whether AKG has the efficacy to mitigate spleen oxidative stress in lipopolysaccharide (LPS)-induced sepsis piglets through the modulation of mitochondrial dynamics and autophagy. Utilizing a 2 × 2 factorial design, the study encompassed 24 piglets subjected to varying diets (basal or 1% AKG) and immune stimulations (saline or LPS) over 21 days. Subsequently, they were injected intraperitoneally with either LPS or saline solution. The results showed that LPS decreased antioxidant capacity, whereas AKG supplementation increased antioxidant activities compared to control group. LPS elevated mitochondrial fission factor, mitochondrial elongation factor 1, mitochondrial elongation factor 2, dynamin-related protein 1, voltage-dependent anion channel 1, and fission 1 mRNA abundance, but reduced mRNA abundance of mitofusin 1, mitofusin 2, and optic atrophy 1 compared to controls. LPS elevated mRNA abundance of autophagy related protein 5, autophagy related protein 7, P62, Beclin1, and interleukin-1ß mRNA abundance compared to controls. However, AKG supplementation mitigated these effects induced by LPS. Additionally, AKG intake was associated with lower protein expressions of microtubule-associated protein light chain 3, Parkin, and PTEN-induced putative kinase 1 compared to LPS-challenged piglets. These results suggested that AKG could alleviate spleen oxidative stress caused by LPS by regulating mitochondrial dynamics and autophagy.

Selenomethionine alleviates chronic heat stress-induced breast muscle injury and poor meat quality in broilers via relieving mitochondrial dysfunction and endoplasmic reticulum stress.

In the present study, the chronic heat stress (CHS) broiler model was developed to investigate the potential protection mechanism of organic selenium (selenomethionine, SeMet) on CHS-induced skeletal muscle growth retardation and poor meat quality. Four hundred Arbor Acres male broilers (680 ± 70 g, 21 d old) were grouped into 5 treatments with 8 replicates of 10 broilers per replicate. Broilers in the control group were raised in a thermoneutral environment (22 ± 2 °C) and fed with a basal diet. The other four treatments were exposed to hyperthermic conditions (33 ± 2 °C, 24 h in each day) and fed on the basal diet supplied with SeMet at 0.0, 0.2, 0.4, and 0.6 mg Se/kg, respectively, for 21 d. Results showed that CHS reduced (P < 0.05) the growth performance, decreased (P < 0.05) the breast muscle weight and impaired the meat quality of breast muscle in broilers. CHS induced protein metabolic disorder in breast muscle, which increased (P < 0.05) the expression of caspase 3, caspase 8, caspase 9 and ubiquitin proteasome system related genes, while decreased the protein expression of P-4EBP1. CHS also decreased the antioxidant capacity and induced mitochondrial stress and endoplasmic reticulum (ER) stress in breast muscle, which increased (P < 0.05) the ROS levels, decreased the concentration of ATP, increased the protein expression of HSP60 and CLPX, and increased (P < 0.05) the expression of ER stress biomarkers. Dietary SeMet supplementation linearly increased (P < 0.05) breast muscle Se concentration and exhibited protective effects via up-regulating the expression of the selenotranscriptome and several key selenoproteins, which increased (P < 0.05) body weight, improved meat quality, enhanced antioxidant capacity and mitigated mitochondrial stress and ER stress. What's more, SeMet suppressed protein degradation and improved protein biosynthesis though inhibiting the caspase and ubiquitin proteasome system and promoting the mTOR-4EBP1 pathway. In conclusion, dietary SeMet supplementation increases the expression of several key selenoproteins, alleviates mitochondrial dysfunction and ER stress, improves protein biosynthesis, suppresses protein degradation, thus increases the body weight and improves meat quality of broilers exposed to CHS.

Zinc glycine chelate ameliorates DSS-induced intestinal barrier dysfunction via attenuating TLR4/NF-κB pathway in meat ducks.

BACKGROUND: Zinc glycine chelate (Zn-Gly) has anti-inflammation and growth-promoting properties; however, the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation is unknown. Three-hundred 1-day-old ducks were divided into 5 groups (6 replicates and 10 ducks per replicate) in a completely randomized design: the control and dextran sulfate sodium (DSS) groups were fed a corn-soybean meal basal diet, and experimental groups received supplements of 70, 120 or 170 mg/kg Zn in form of Zn-Gly. The DSS and treatment groups were given 2 mL of 0.45 g/mL DSS daily during d 15-21, and the control group received normal saline. The experiment lasted 21 d. RESULTS: Compared with DSS group, 70, 120 and 170 mg/kg Zn significantly increased body weight (BW), villus height and the ratio of villus to crypt, and significantly decreased the crypt depth of jejunum at 21 d. The number of goblet cells in jejunal villi in the Zn-Gly group was significantly increased by periodic acid-Schiff staining. Compared with control, the content of intestinal permeability marker D-lactic acid (D-LA) and fluxes of fluorescein isothiocyanate (FITC-D) in plasma of DSS group significantly increased, and 170 mg/kg Zn supplementation significantly decreased the D-LA content and FITC-D fluxes. Compared with control, contents of plasma, jejunum endotoxin and jejunum pro-inflammatory factors IL-1ß, IL-6 and TNF-α were significantly increased in DSS group, and were significantly decreased by 170 mg/kg Zn supplementation. Dietary Zn significantly increased the contents of anti-inflammatory factors IL-10, IL-22 and sIgA and IgG in jejunum. Real-time PCR and Western blot results showed that 170 mg/kg Zn supplementation significantly increased mRNA expression levels of CLDN-1 and expression of OCLN protein in jejunum, and decreased gene and protein expression of CLDN-2 compared with DSS group. The 120 mg/kg Zn significantly promoted the expressions of IL-22 and IgA. Dietary Zn-Gly supplementation significantly decreased pro-inflammatory genes IL-8 and TNF-α expression levels and TNF-α protein expression in jejunum. Additionally, Zn significantly reduced the gene and protein expression of TLR4, MYD88 and NF-κB p65. CONCLUSIONS: Zn-Gly improved duck BW and alleviated intestinal injury by regulating intestinal morphology, barrier function and gut inflammation-related signal pathways TLR4/MYD88/NF-κB p65.

Effects of dietary N-carbamylglutamate supplementation on the modulation of microbiota and Th17/Treg balance-related immune signaling after lipopolysaccharide challenge.

BACKGROUND: This study aimed to evaluate the effects of N-carbamylglutamate (NCG) on piglets' growth performance and immune response, and to unravel the mechanisms of such effects. In a 2 × 2 factorial design including diet (with or without NCG) and immunological challenge (saline or lipopolysaccharide (LPS)), 24 piglets were randomly distributed into four groups. After being fed a basic diet or a NCG-supplemented diet for 21 days, piglets were administered LPS or saline intraperitoneally. RESULTS: The results showed that NCG increased the average daily gain and average daily feed intake, and the feed conversion ratio of piglets, and alleviated the adverse effects of LPS stimulation on intestinal morphology. At the phylum level, NCG reversed the increase in the abundance of Firmicutes and the reduction in that of Actinomycete caused by LPS stimulation. At the genus level, NCG increased the abundance of Lactobacillus, Blautia, norank_Butyricicoccaceae, Subdoligranulum, and Ruminococcus_gauvreauii_group, and LPS decreased the abundance of Escherichia-Shigella and Ruminococcus_gauvreauii_group. The short-chain fatty acid content was increased by NCG, but LPS reduced its content. N-Carbamylglutamate also inhibited significantly the LPS-induced increase in the relative expression of signal transducer and activator of transcription (STAT) 3, related orphan receptor (RAR) c, and pro-inflammatory cytokines, and the decrease in the relative expression of STAT5, forkhead box P3, IL-10 and transforming growth factor beta 1 mRNA. A significant correlation was found between intestinal microbiota and inflammatory cytokines and short-chain fatty acids. CONCLUSION: N-Carbamylglutamate can improve piglets' growth performance. It can also attenuate LPS-induced intestinal inflammation by modulating microbiota and Th17/Treg balance-related immune signaling pathways. © 2023 Society of Chemical Industry.

Hydroxy Selenomethionine Exert Different Protective Effects Against Dietary Oxidative Stress-Induced Inflammatory Responses in Spleen and Thymus of Pigs.

Oxidative stress (OS) is widespread in animal husbandry, which causes edema in immune organs and suppresses immune function of animals. Selenium (Se) is an essential trace element involved in immune regulation and improves animals' immunity. In present study, growing and finishing pigs were used to determine the protective effects of the new organic Se (hydroxy selenomethionine, OH-SeMet) on dietary oxidative stress (DOS) induced inflammatory responses, and the corresponding response of selenotranscriptome in spleen and thymus. Forty castrated male pigs (25.0 ± 3.0 kg) were randomly grouped into 5 dietary treatments (n = 8) and fed on basal diet (formulated with normal corn and normal oils) or oxidized diet (formulated with aged corn and oxidized oils) supplied with 0.0, 0.3, 0.6, or 0.9 mg Se/kg OH-SeMet, after 16 weeks, the corresponding indicators were determined. Results showed that DOS moderately increased the spleen and thymus index, decreased the antioxidant capacity of serum, spleen and thymus, and increased the concentration of serum inflammatory cytokines (IL-6 and TNF-α). The inflammatory response in spleen and thymus under DOS were discrepancies, DOS increased the expression of inflammation-related gene (IFN-ß and TNF-α) in thymus, while exhibited no impact on that of the spleen. Dietary OH-SeMet supplementation exhibited protective effects, which decreased the spleen and thymus index, improved the antioxidant capacity of serum, spleen and thymus, and decreased the serum IL-1ß and IL-6 levels. Se supplementation exhibited limited impact on the inflammation-related genes in spleen, except decreased the mRNA expression of IL-8. On the contrary, Se supplementation showed more impact on that of the thymus, which decreased the mRNA expression of IL-8 and TNF-α, increased the expression of IFN-ß, IL-6, IL-10, and MCP1. In addition, selenotranscriptome responsive to dietary Se levels in spleen and thymus were discrepancies. Se supplementation increased the mRNA expression of  the selenotranscriptome in thymus, while exhibited limited impact on that of in spleen. In conclusion, dietary OH-SeMet supplementation mitigates the DOS-induced immunological stress by increasing the antioxidant capacity and altering the expression of inflammation-related genes and selenotranscriptome in immune organs, and these response in spleen and thymus were discrepancies.

Compound bioengineering protein improves growth performance and intestinal health in broiler chickens under high-temperature conditions.

In recent years, more frequent and prolonged periods of high ambient temperature in summer compromised poultry production worldwide. This study was conducted to investigate the effects of compound bioengineering protein (CBP) on the growth performance and intestinal health of broilers under high ambient temperatures. A total of 400 one-day-old Arbor Acres birds were randomly distributed into five treatment groups: control group (CON) with basal diet, or a basal diet supplemented with CBP 250, 500, 750, and 1,000 mg/kg, respectively. The trial lasted 42 d, all birds were raised at normal ambient temperature for the first 21 d and then subjected to the artificial hyperthermal condition with the temperature at 32 ±â€…2 °C and relative humidity at 60 ±â€…5% during 22 to 42 d. Dietary CBP supplementation improved the growth performance and serum antioxidant capacity (total antioxidant capacity and total superoxide dismutase), and decreased serum cortisol, aminotransferase, and alkaline phosphatase of broilers. Dietary CBP inclusion enhanced intestinal barrier function by promoting intestinal morphology and reducing intestinal permeability (diamine oxidase), increased the intestinal antioxidant capacity by elevating glutathione peroxidase activity in the duodenum, reducing malondialdehyde content in the jejunum. Dietary CBP supplementation also alleviated intestinal inflammation by decreasing interleukin (IL)-6 content in the jejunum and ileum, promoting IL-10 levels in the ileum, down-regulating the mRNA abundance of intestinal inflammatory-related genes interferon-gamma (IFN-γ) in the duodenum and up-regulating IL-10 in the jejunum. Additionally, CBP increased the population of total bacteria and Lactobacillus in cecal chyme. Collectively, dietary CBP inclusion exerts beneficial effects on the broilers, which are reflected by enhancing antioxidant capacity, promoting intestinal barrier function, ameliorating intestinal immune response, and regulating intestinal bacteria, thus improving the growth performance of broilers under high-temperature conditions. In general, 750 mg/kg CBP supplementation is more effective.

Extreme high ambient temperature in summer occurs frequently around the world, which causes severe economic losses in the broiler industry, and impairs food safety. Improving the high-temperature resistance of broilers is beneficial to the sustainable development of the broiler industry. Dietary supplementation of anti-stress additives is an effective way to prevent high-temperature stress in broilers. Antimicrobial peptides are excellent anti-stress additives that exhibit multiple biological functions, such as against microbial infection, improving antioxidant capacity and immune function, and perfecting the intestinal health of broilers. In the present study, we added the compound bioengineering protein (CBP) (two bioengineering proteins containing functional fragments of antimicrobial peptides) in diets to investigate the potential protective effects of CBP for broilers under high temperatures. Our present results indicate that dietary CBP supplementation enhances the growth performance of broilers exposed to high temperatures. This improvement is attributed to the increased antioxidant capacity, improved intestinal barrier function, ameliorated intestinal immune function, and improved intestinal bacteria. These results provide a theoretical foundation for CBP utilization in diets to ameliorate growth performance and intestinal health of broilers under high temperatures.

Selenomethionine alleviates environmental heat stress induced hepatic lipid accumulation and glycogen infiltration of broilers via maintaining mitochondrial and endoplasmic reticulum homeostasis.

With the increasing of global mean surface air temperature, heat stress (HS) induced by extreme high temperature has become a key factor restricting the poultry industry. Liver is the main metabolic organ of broilers, HS induces liver damage and metabolic disorders, which impairs the health of broilers and affects food safety. As an essential trace element for animals, selenium (Se) involves in the formation of antioxidant system, and its biological functions are generally mediated by selenoproteins. However, the mechanism of Se against HS induced liver damage and metabolic disorders in broilers is inadequate. Therefore, we developed the chronic heat stress (CHS) broiler model and investigated the potential protection mechanism of organic Se (selenomethionine, SeMet) on CHS induced liver damage and metabolic disorders. In present study, CHS caused liver oxidative damage, and induced hepatic lipid accumulation and glycogen infiltration of broilers, which are accompanied by mitochondrial dysfunction, abnormal mitochondrial tricarboxylic acid (TCA) cycle and endoplasmic reticulum (ER) stress. Dietary SeMet supplementation increased the hepatic Se concentration and exhibited protective effects via promoting the expression of selenotranscriptome and several key selenoproteins (GPX4, TXNRD2, SELENOK, SELENOM, SELENOS, SELENOT, GPX1, DIO1, SELENOH, SELENOU and SELENOW). These key selenoproteins synergistically improved the antioxidant capacity, and mitigated the mitochondrial dysfunction, abnormal mitochondrial TCA cycle and ER stress, thus recovered the hepatic triglyceride and glycogen concentration. What's more, SeMet supplementation suppressed lipid and glycogen biosynthesis and promoted lipid and glycogen breakdown in liver of broilers exposed to CHS though regulating the AMPK signals. Overall, our present study reveals a potential mechanism that Se alleviates environment HS induced liver damage and glycogen and lipid metabolism disorders in broilers, which provides a preventive and/or treatment measure for environment HS-dependent hepatic metabolic disorders in poultry industry.

Different Dietary Sources of Selenium Alleviate Hepatic Lipid Metabolism Disorder of Heat-Stressed Broilers by Relieving Endoplasmic Reticulum Stress.

As global warming continues, the phenomenon of heat stress (HS) in broilers occurs frequently. The alleviating effect of different selenium (Se) sources on HS-induced hepatic lipid metabolism disorders in broilers remains unclear. This study compared the protective effects of four Se sources (sodium selenite; selenium yeast; selenomethionine; nano-Se) on HS-induced hepatic lipid metabolism disorder and the corresponding response of selenotranscriptome in the liver of broilers. The results showed that HS-induced liver injury and hepatic lipid metabolism disorder, which were reflected in the increased activity of serum alanine aminotransferase (ALT), the increased concentration of triacylglycerol (TG) and total cholesterol (TC), the increased activity of acetyl-CoA carboxylase (ACC), diacylglycerol O-acyltransferase (DGAT) and fatty acid synthase (FAS), and the decreased activity of hepatic lipase (HL) in the liver. The hepatic lipid metabolism disorder was accompanied by the increased mRNA expression of lipid synthesis related-genes, the decreased expression of lipidolysis-related genes, and the increased expression of endoplasmic reticulum (ER) stress biomarkers (PERK, IRE1, ATF6, GRP78). The dietary supplementation of four Se sources exhibited similar protective effects. Four Se sources increased liver Se concentration and promoted the expression of selenotranscriptome and several key selenoproteins, enhanced liver antioxidant capacity and alleviated HS-induced ER stress, and thus resisted the hepatic lipid metabolism disorders of broilers exposed to HS. In conclusion, dietary supplementation of four Se sources (0.3 mg/kg) exhibited similar protective effects on HS-induced hepatic lipid metabolism disorders of broilers, and the protective effect is connected to the relieving of ER stress.

Dietary Betaine improves the intestinal health and growth performance of heat-stressed growing rabbits in summer.

The main objective of this study is to explore how various amounts of Bet affect growth performance, nutritional digestibility, and intestinal health of growing rabbits under high-temperature environment in summer. A total of 150 healthy 35-d-old weaned QiXing meat rabbits (Germany White rabbit × Sichuan White rabbit) were individually assigned to five treatments, each with 30 replicates and one rabbit per replicate. The control group was fed with basal diet, while the experimental group received a basal diet supplemented with 0.75, 1.0, 1.5, and 2.0 g Bet/kg diet, respectively. During the whole experimental stage, all animals can eat and drink freely, and they were kept in the rabbit house with an average daily temperature of 30.11 ±â€…0.5 ℃ and a relative humidity of 71.02 ±â€…5.07%. The results showed that dietary supplementation with 1.5 g/kg Bet increased average daily gain and decreased feed to gain ratio from days 1 to 42 as compared to the control group (P < 0.05), adding 0.75, 1.0, 1.5, and 2.0 g/kg Bet increased average daily gain and average daily feed intake from days 22 to 42 (P < 0.05), and increased the nutritional digestibility of acid detergent fiber (P < 0.05). Furthermore, dietary supplementation with 1.0, 1.5, and 2.0 g/kg Bet reduced d-lactate content and diamine oxidase activity in the serum (P < 0.05). Compared to the control group, supplementation of 0.75 and 1.5 g/kg Bet improved glutathione peroxidase activities in the duodenum and ileum, adding 0.75, 1.0, 1.5, and 2.0 g/kg Bet decreased malonaldehyde content in the duodenum and jejunum (P < 0.05). Moreover, the supplement of 1.5 and 2.0 g/kg Bet upregulated JAM-2 and IL-10 levels in the jejunum (P < 0.05). In conclusion, supplementation with Bet in the diet improves the growth performance, nutrient digestibility, and intestinal health of growing rabbits under high-temperature environments, and the 1.5 g Bet/kg diet group has the best effect.

Due to the lack of functional sweat glands, rabbits find it difficult to release excess heat under high-temperature conditions, resulting in heat stress. This high-level temperature condition leads to substantial damage to growth performance and intestinal health resulting in significant financial losses for the meat rabbit industry. This study found that adding betaine (Bet) to the diet can improve the growth performance and intestinal barrier integrity of heat-stressed growing rabbits, which may be related to improving intestinal antioxidant capacity and immune status. 1.5 g Bet/kg diet group showed better effects than 0, 0.75, 1.0, and 2.0 g Bet/kg diet groups in improving growth performance and intestinal health of heat-stressed growing rabbits.

Dietary Taurine Supplementation Improves the Meat Quality, Muscle Fiber Type, and Mitochondrial Function of Finishing Pigs.

This study investigated the effects of dietary supplementation with taurine (TAU) on the meat quality, muscle fiber type, and mitochondrial function of finishing pigs. The results demonstrated that TAU significantly increased the a* value while decreasing b*45 min, L*24 h, and drip loss24 h and drip loss48 h in the longissimus dorsi (LD) muscle. Dietary supplemented with TAU reduced the content of lactate and the glycolytic potential (GP) in the LD muscle. Dietary supplemented with TAU enhanced the oxidative fiber-related gene expression as well as increased succinic dehydrogenase and malate dehydrogenase activities while reducing lactate dehydrogenase activity. Furthermore, dietary supplementation with TAU increased the contents of mtDNA and ATP and mitochondrial function-related gene expression. Moreover, TAU enhanced the mRNA expressions of calcineurin (CaN) and nuclear factor of activated T cells c1 (NFATc1) and protein expressions of CNA and NFATc1. The results indicate that dietary TAU supplementation improves meat quality and mitochondrial biogenesis and function and promotes muscle fiber-type conversion from the glycolytic fiber to the oxidative fiber via the CaN/NFATc1 pathway.

Tryptophan alleviates lipopolysaccharide-induced liver injury and inflammation by modulating necroptosis and pyroptosis signaling pathways in piglets.

The liver plays crucial roles in material metabolism and immune response. Bacterial endotoxin can cause various liver diseases, thereby causing significant economic losses to pig industry. Tryptophan is an essential amino acid in piglets. However, whether tryptophan can alleviate liver injury and inflammation by regulating necroptosis and pyroptosis has not been clarified. This study aimed to investigate whether dietary tryptophan can alleviate lipopolysaccharide (LPS)-induced liver injury in weaned piglets. 18 weaned piglets were randomly distributed to three treatments, each with 6 replicates: (1) control; (2) LPS-challenged control; (3) LPS + 0.2% tryptophan. After feeding with control or 0.2% tryptophan-supplemented diets for 35 d, pigs were intraperitoneally injected with saline or LPS (100 mg/kg body weight). At 4 h post-injection, blood samples and liver were collected. Results indicated that tryptophan reduced alanine aminotransferase, aspartate aminotransferase, decreased the mRNA expression and protein expression of 70-kDa heat shock proteins. Moreover, tryptophan increased the mRNA expression and protein expression of claudin-1, occludin and zonula occludens and decreased hydrogen peroxide and malondialdehyde contents, and increased catalase, glutathione peroxidase and total superoxide dismutase activities and proinflammatory cytokine levels in the liver. Meanwhile, tryptophan inhibited pyroptosis-related and necroptosis-related protein expression in liver. Collectively, tryptophan could relieve liver damage, increased the antioxidant capacity and reduced inflammation by inhibiting pyroptosis and necroptosis signaling pathways.

Organic zinc glycine chelate is better than inorganic zinc in improving growth performance of cherry valley ducks by regulating intestinal morphology, barrier function, and the gut microbiome.

Zinc (Zn) is an essential trace element that has physiological and nutritional functions. However, excessive use of Zn can lead to waste of resources. In this study, we compared the effects of inorganic (ZnSO4) and organic Zn glycine chelate (Zn-Gly) on the growth performance, intestinal morphology, immune function, barrier integrity, and gut microbiome of Cherry Valley ducks. We randomly divided 180 one-day-old male meat ducks into three groups, each with six replicates of 10 birds: basal diet group (CON), basal diet with 70 mg Zn/kg from ZnSO4 (ZnSO4 group), and basal diet with 70 mg Zn/kg from Zn-Gly (Zn-Gly group). After 14 and 35 d of feeding, birds in the Zn groups had significantly increased body weight and average daily gain (ADG), decreased intestinal permeability indicator d-lactate, improved intestinal morphology and barrier function-related tight junction protein levels, and upregulated mucin 2 and secretory immunoglobulin A levels compared to the control (P < 0.05). Additionally, compared to the ZnSO4 group, we found that supplementation with Zn-Gly at 70 mg/kg Zn resulted in the significant increase of body weight at 35 d, 1 to 35 d ADG and average daily feed intake, villus height at 14 and 35 d, secretory immunoglobulin A and immunoglobulin G at 14 d, and mucin 2 mRNA level at 14 d (P < 0.05). Compared with the control group, dietary Zn had a significant effect on the gene expression of metallothionein at 14 and 35 d (P < 0.05). 16S rRNA sequencing showed that Zn significantly increased alpha diversity (P < 0.05), whereas no differences in beta diversity were observed among groups (P > 0.05). Dietary Zn significantly altered the cecal microbiota composition by increasing the abundances of Firmicutes, Blautia, Lactobacillus, Prevotellaceae NK3B31, and [Ruminococcus] torques group and reducing that of Bacteroides (P < 0.05). Spearman correlation analysis revealed that the changes in microbiota were highly correlated (P < 0.05) with growth performance, intestinal morphology, and immune function-related parameters. Taken together, our data show that, under the condition of adding 70 mg/kg Zn, supplementation with Zn-Gly promoted growth performance by regulating intestinal morphology, immune function, barrier integrity, and gut microbiota of Cherry Valley ducks compared with the use of ZnSO4 in feed.

Zinc (Zn) is an essential trace element that is required for physiological and nutritional functions, but excessive use of Zn can lead to environmental pollution. Few studies have directly compared the impact of different Zn sources on growth performance and intestinal barrier function in Cherry Valley ducks. This study was conducted to investigate the effects of two sources of Zn (inorganic ZnSO4 or organic Zn glycine chelate, Zn-Gly) on growth performance, intestinal morphology, barrier function, and gut microbiome of ducks. Compared to the ZnSO4 group, we found that supplementation with Zn-Gly resulted in the significant increase of body weight at 35 d, 1 to 35 d average daily gain and average daily feed intake, villus height at 14 and 35 d, secretory immunoglobulin A and immunoglobulin G at 14 d, and mucin 2 mRNA level at 14 d. At the genus level, the relative abundance of Blautia was higher in the Zn-Gly group than that in the control and ZnSO4 group. Therefore, Zn-Gly supplementation at 70 mg/kg Zn had positive effects in promoting growth performance by regulating intestinal morphology, barrier function, and gut microbiota of ducks when compared with the same dosage use of ZnSO4 in feed.

Selenoproteins synergistically protect porcine skeletal muscle from oxidative damage via relieving mitochondrial dysfunction and endoplasmic reticulum stress.

BACKGROUND: The skeletal muscle of pigs is vulnerable to oxidative damage, resulting in growth retardation. Selenoproteins are important components of antioxidant systems for animals, which are generally regulated by dietary selenium (Se) level. Here, we developed the dietary oxidative stress (DOS)-inducing pig model to investigate the protective effects of selenoproteins on DOS-induced skeletal muscle growth retardation. RESULTS: Dietary oxidative stress caused porcine skeletal muscle oxidative damage and growth retardation, which is accompanied by mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and protein and lipid metabolism disorders. Supplementation with Se (0.3, 0.6 or 0.9 mg Se/kg) in form of hydroxy selenomethionine (OH-SeMet) linearly increased muscular Se deposition and exhibited protective effects via regulating the expression of selenotranscriptome and key selenoproteins, which was mainly reflected in lower ROS levels and higher antioxidant capacity in skeletal muscle, and the mitigation of mitochondrial dysfunction and ER stress. What's more, selenoproteins inhibited DOS induced protein and lipid degradation and improved protein and lipid biosynthesis via regulating AKT/mTOR/S6K1 and AMPK/SREBP-1 signalling pathways in skeletal muscle. However, several parameters such as the activity of GSH-Px and T-SOD, the protein abundance of JNK2, CLPP, SELENOS and SELENOF did not show dose-dependent changes. Notably, several key selenoproteins such as MSRB1, SELENOW, SELENOM, SELENON and SELENOS play the unique roles during this protection. CONCLUSIONS: Increased expression of selenoproteins by dietary OH-SeMet could synergistically alleviate mitochondrial dysfunction and ER stress, recover protein and lipid biosynthesis, thus alleviate skeletal muscle growth retardation. Our study provides preventive measure for OS-dependent skeletal muscle retardation in livestock husbandry.

Caffeic acid improves intestinal barrier functions by regulating colonic bacteria and tight junction protein expression and alleviating inflammation in weaning piglets.

The experiment investigated the effect of caffeic acid on bacteria, short-chain fatty acids (SCFA), and the expression of tight junction protein and inflammation related genes in the colon of weaning piglets. Thirty-six weaning piglets were allocated to three treatment groups, which were fed with a basal diet, a basal diet supplemented with 250 mg/kg or 500 mg/kg caffeic acid for 28 days. The results showed that caffeic acid treatment increased the contents of acetate acid, propionate acid and total SCFA. Moreover, real-time quantitative PCR showed that the number of Bifidobacterium (p < 0.05) and Lactobacillus (p < 0.05) were increased and the number of Escherichia coli (p < 0.05) was decreased by caffeic acid in colonic mucosa. Real-time quantitative PCR also showed that the mRNA levels of zonula occludens-1 (p < 0.01), claudin-1 (p < 0.01), occludin (p < 0.01), mucin 1 (MUC1) (p < 0.01), MUC2 (p < 0.01), interleukin 4 (IL-4) (p < 0.01) and IL-10 (p < 0.05) were increased, while the mRNA expression levels of histone deacetylases (p < 0.01), IL-1 (p < 0.01), IL-6 (p < 0.01) and tumor necrosis factor-α (TNF-α) (p < 0.01) were decreased, by caffeic acid in colonic mucosa. These results suggested that caffeic acid could improve intestinal barrier function in weaned pigs, which might be mediated by regulating colonic bacteria and tight junction protein expression and alleviating inflammation.

Hydroxy-Selenomethionine Mitigated Chronic Heat Stress-Induced Porcine Splenic Damage via Activation of Nrf2/Keap1 Signal and Suppression of NFκb and STAT Signal.

Chronic heat stress (CHS) compromised the immunity and spleen immunological function of pigs, which may associate with antioxidant suppression and splenocyte apoptosis and splenic inflammation. Selenium (Se) exhibited antioxidant function and immunomodulatory through selenoprotein. Thus, this study aimed to investigate the protective effect of dietary hydroxy-selenomethionine (Selisso®, SeO) on chronic heat stress (CHS)-induced porcine splenic oxidative stress, apoptosis and inflammation. Growing pigs were raised in the thermoneutral environment (22 ± 2 °C) with the basal diet (BD), or raised in hyperthermal conditions (33 ± 2 °C) with BD supplied with 0.0, 0.2, 0.4 and 0.6 mg Se/kg SeO for 28 d, respectively. The results showed that dietary SeO supplementation recovered the spleen mass and enhanced the splenic antioxidant capacity of CHS growing pigs. Meanwhile, SeO activated the Nrf2/Keap1 signal, downregulated p38, caspase 3 and Bax, inhibited the activation of NFκb and STAT3, and enhanced the protein expression level of GPX1, GPX3, GPX4, SELENOS and SELENOF. In summary, SeO supplementation mitigates the CHS-induced splenic oxidative damages, apoptosis and inflammation in pigs, and the processes are associated with the activation of Nrf2/Keap1 signal and the suppression of NFκb, p38(MAPK) and STAT signal. It seems that the antioxidant-related selenoproteins (GPXs) and functional selenoproteins (SELENOS and SELENOF) play important roles in the alleviation processes.

Dietary tryptophan supplementation enhances mitochondrial function and reduces pyroptosis in the spleen and thymus of piglets after lipopolysaccharide challenge.

The thymus and spleen, the main reservoirs for T lymphocytes, modulate the innate immune response. Oxidative stress, excessive inflammation and abnormal pyroptosis can cause dysfunction of these organs. This study aimed to examine whether tryptophan supplementation can improve growth performance and mitochondrial function via the adenosine 5'-monophosphate-activated protein kinase (AMPK)/sirtuin1 (Sirt1)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) signalling pathway and decrease pyroptosis via the nucleotidebinding oligomerisation domain-like receptor protein 3 (NLRP3)/caspase-1/gasderminD (GSDMD) signalling pathway in the spleen and thymus of piglets after lipopolysaccharide (LPS) challenge. Eighteen weaned piglets were allotted to three treatment groups: non-challenged control, LPS-challenged control and LPS + 0.2% tryptophan. On day 35, the pigs in the LPS and LPS + 0.2% tryptophan groups were injected with 100 µg/kg BW LPS, whereas those in the control group were administered with sterile saline. At 4 h postchallenge, the weaned piglets were sacrificed, and their thymuses and spleens were collected. Results showed that tryptophan enhanced growth performance and antioxidant status by increasing catalase, glutathione peroxidase and total superoxide dismutase activities and decreasing malondialdehyde and reactive oxygen species contents. Tryptophan also reduced the mRNA levels of proinflammatory cytokine genes and enhanced mitochondrial function by increasing the mRNA levels of mitochondrial transcription factor A, nuclear respiratory factor-1, mitochondria transcription factor B1, AMPKα1, AMPKα2, Sirt1 and PGC1α and the protein expression of phosphorylated AMPK, Sirt1 and PGC1α. It also reduced pyroptosis by decreasing the mRNA levels of NLRP3, apoptosis-associated speck-like protein containing CARD, caspase-1 and GSDMD and the protein expression of NLRP3, caspase-1 and GSDMD. These results indicate that tryptophan supplementation enhances growth performance and mitochondrial function via the AMPK/Sirt1/PGC1α signalling pathway and decreases pyroptosis via the NLRP3/caspase-1/GSDMD signalling pathway in the spleen and thymus of LPS-challenged piglets.

Effect of dietary licorice flavonoids powder on performance, intestinal immunity and health of weaned piglets.

Licorice flavonoids, a bioactive substance derived from glycyrrhiza, have been reported for many pharmacological properties and are beneficial to animal health. This study aimed to explore the effects of licorice flavonoids powder (LFP) on growth performance and intestinal health of piglets. A total of 96 weaned piglets were randomly assigned into four treatments and supplemented with 0, 50, 150 and 250 mg/kg LFP for 5 weeks. Dietary LFP supplementation tended to increase (p = 0.068) average daily gain (ADG) and reduce (p = 0.089) the feed intake/body gain (F/G) of piglets than that of the control group during 15-35 days; and concentrations of LFP supplementation reduced (p < 0.01) diarrhoea index during 14-35 days and 0-35 days. Piglets fed on diets supplied with LFP had a lower (p < 0.05) pH in caecum and colon. Dietary LFP supplementation increased (p < 0.01) the villi height and the ratio of villi height/crypt depth in duodenum, and reduced (p < 0.05) crypt depth in duodenum. Compared with the control group, 250 mg/kg LFP supplementation up-regulated (p < 0.05) the mRNA level of occludin (OCLN) in ileum. Meanwhile, dietary LFP supplementation down-regulated (p < 0.05) mRNA abundance of Interleukin (IL)-1ß, IL-8 and induced nitrogen monoxide synthase (INOS) in duodenum. Dietary 150 mg/kg LFP supplementation down-regulated (p < 0.05) mRNA abundance of IL-1ß and 250 mg/kg LFP up-regulated (p < 0.05) the expression of IL-10 in ileum. In summary, dietary LFP supplementation has a trend to improve the performance of weaning piglets, those improvements are accompanied by reduction in diarrhoea, enhancement of intestinal morphological structure, barrier function, immune function, and development. In general, 150 mg/kg LFP supplementation is more effective.

Dietary supplementation of ferrous glycinate improves intestinal barrier function by modulating microbiota composition in Cherry Valley ducks.

Ferrous glycinate (Fe-Gly) has been increasingly used as iron fortification in the diets of weaned piglets and broilers, but the effect of Fe-Gly on intestinal barrier function in meat ducks has not been well defined. This study therefore investigated the effect of Fe-Gly on apparent nutrient utilization, hematological indices, intestinal morphological parameters, intestinal barrier function and microbial composition in meat ducks. A total of 672 one-day-old Cherry Valley ducks were randomly divided into 6 treatments (8 replicates for each treatment and 14 ducks for each replicate) and fed diets with 0 (control), 30, 60, 90 and 120 mg/kg Fe-Gly or 120 mg/kg FeSO4 for 35 d. The results showed that diets supplemented with Fe-Gly significantly increased average daily gain (ADG), average daily feed intake (ADFI), hematocrit (HCT), mean cell volume (MCV), the apparent utilization of dry matter (DM) and metabolizable energy (ME), villus height (VH) and villus height-to-crypt depth ratio (V:C) (P < 0.05). Fe-Gly also significantly up-regulated barrier-related genes including zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), mucin 2 (MUC2) and lysozyme (LYZ) (P < 0.05), and down-regulated the mRNA expression of claudin-2 (CLDN2) and occludin (OCLN) in the jejunum (P < 0.05). The 16S rRNA sequence analysis indicated that the diet with Fe-Gly had a higher relative abundance of Intestinimonas and Romboutsia (P < 0.05), which have an ability to produce short chain fatty acids (SCFAs), especially butyric acid. It also decreased the relative abundance of pathobiont, including Megamonas, Eubacterium_coprostanoligenes_group and Plebeius (P < 0.05). Additionally, diets supplemented with 120 mg/kg Fe-Gly significantly increased the apparent utilization of DM and ME (P < 0.05) and decreased the relative abundance of Megamonas_unclassified and Bacteroides_unclassified compared with those fed 120 mg/kg FeSO4 (P < 0.05). These results revealed that diets supplemented with Fe-Gly exerted a potent beneficial effect on physical, chemical, immune and microbial barriers, thereby improving the integrity of the intestinal structure, promoting the digestion and absorption of nutrients to a certain extent, and ultimately elevating the growth performance of ducks.