The involvement of NF-κB/P38 pathways in Scutellaria baicalensis extracts attenuating of Escherichia coli K88-induced acute intestinal injury in weaned piglets

Involvement of the AMPK Pathways in Muscle Development Disparities across Genders in Muscovy Ducks

The differences in muscle development potential between male and female ducks lead to variations in body weight, significantly affecting the growth of the Muscovy duck meat industry. The aim of this study is to explore the regulatory mechanisms for the muscle development differences between genders. Muscovy ducks of both sexes were selected for measurements of body weight, growth traits, hormone levels, and muscle gene expression. The results show that male ducks compared to females had greater weight and growth traits (p < 0.05). Compared to male ducks, the level of serum testosterone in female ducks was decreased, and the estradiol levels were increased (p < 0.05). The RNA-seq analysis identified 102 upregulated and 49 downregulated differentially expressed genes. KEGG analysis revealed that among the top 10 differentially enriched pathways, the AMPK signaling pathway is closely related to muscle growth and development. Additionally, the mRNA and protein levels of CD36, CPT1A, LPL, and SREBP1 were increased and the P-AMPK protein level decreased in the female ducks compared to the male ducks (p < 0.05). In conclusion, muscle development potential difference between male and female ducks is regulated by sex hormones. This process is likely mediated through the activation of the AMPK pathway.

Growth differentiation factor 9 activates the TGF-β pathway in follicle atresia of Muscovy ducks

Muscovy ducks' high broodiness hinders industry growth. Studying broodiness regulation contributes to the theoretical foundation for enhancing reproductive performance in Muscovy ducks. Experiment 1, a total of 18 Muscovy ducks were divided into 2 groups: Laying group (LO) and Broody group (BO). To collect ovaries for morphological and transcriptome analysis. Experiment 2, Primary Muscovy ducks granulosa cells (GC) were isolated and treated with or without GDF9 at appropriate concentrations as indicated. Experiment 3, GC were treated with or without GDF9 in the presence or absence of a receptor inhibitor. The cell viability, cell apoptosis rate and levels of TGF-β pathway were determined. In vivo, there was a gradual disappearance of follicles in the ovaries and accompanied by follicle atrophy and a concentration of cytoplasm in BO group. The transcriptome expression profile revealed a total of 1,185 up-regulated differentially expressed transcripts (DEs) and 1,258 down-regulated DEs in the BO group compared to the LO group. The up-regulated differentially expressed GDF9 is involved in regulating the TGF-β pathway, which is among the top 10 pathways identified through the KEGG pathway analysis (P < 0.05). Additionally, the fluorescence intensity of apoptosis is primarily observed in the granulosa layers of the ovary. Compared to the LO group, the mRNA level of TGF-β pathway and the protein of GDF9 and p-Smad2/3 were increased in ovary of the BO group (P < 0.05). In vitro, GDF9 supplementation demonstrated does-related promotion of GC (P < 0.01). Compared to CTRL group, 12 ng/mL GDF9 supplementation to GC increased the rate of cell apoptosis, the mRNA and protein expression of TGF-β pathway and the apoptosis-related genes. Pretreatment of GC with GDF9-receptor inhibitor largely abrogated the negative function of GDF9 treatment (P < 0.05). In summary, granulosa cell apoptosis leading to follicle atresia in broodiness of Muscovy ducks is associated with GDF9 activation of the TGF-β pathway. This discovery lays a solid foundation for understanding duck follicular development and enhancing egg production in Muscovy ducks.

Pyrroloquinoline Quinone Alleviates Intestinal Inflammation and Cell Apoptosis via the MKK3/6-P38 Pathway in a Piglet Model

This study investigates the underlying mechanism through which dietary supplementation of pyrroloquinoline quinone disodium (PQQ) alleviates intestinal inflammation and cell apoptosis in piglets challenged with lipopolysaccharide (LPS). Seventy-two barrows were divided into three groups: control (CTRL), LPS challenged (LPS), and LPS challenged with PQQ supplementation (PQQ + LPS). On d 7, 11, and 14, piglets received intraperitoneal injections of LPS or 0.9% of NaCl (80 μg/kg). After a 4 h interval following the final LPS injection on d 14, blood samples were obtained, and all piglets were euthanized for harvesting jejunal samples. The results showed that dietary supplementation of PQQ improved the damage of intestinal morphology, increased the down-regulated tight junction proteins, and reduced the increase of serum diamine oxidase activity, the intestinal fatty acid binding protein, and TNF-α levels in piglets challenged with LPS (p < 0.05). The proteomics analysis revealed a total of 141 differentially expressed proteins (DEPs), consisting of 64 up-regulated DEPs and 77 down-regulated DEPs in the PQQ + LPS group compared to the LPS group. The KEGG pathway analysis indicated enrichment of the tight junction pathway and the apoptosis pathway (p < 0.05). Compared to the LPS group, the piglets in the PQQ + LPS group had increased levels of Bcl-2 protein, reduced positive apoptosis signals, and a decrease in the abundance of MKK 3/6 and p-p38 proteins (p < 0.05). In conclusion, dietary supplementation of PQQ could alleviate jejunal inflammatory damage and cell apoptosis in piglets challenged with LPS through the MKK3/6-p38 signaling pathway.

Effects of Dietary Lonicera flos and Sucutellaria baicalensis Mixed Extracts Supplementation on Reproductive Performance, Umbilical Cord Blood Parameters, Colostrum Ingredients and Immunoglobulin Contents of Late-Pregnant Sows

The present study aimed to determine the effects of dietary Lonicera flos and Sucutellaria baicalensis mixed extract (LSE) supplementation during the late-pregnancy period on the reproductive performance, umbilical cord blood hematological parameters, umbilical cord serum biochemical parameters, immune indices, hormone levels, colostrum ingredients, and immunoglobulin contents of sows. A total of 40 hybrid pregnant sows were randomly assigned to the control group (CON; sows fed a basal diet) and LSE group (LSE; sows fed a basal diet supplemented with 500 g/t PE). The results indicated that dietary LSE supplementation significantly increased (p < 0.05) the number of alive and healthy piglets and the litter weight at birth, and significantly increased (p < 0.05) the platelet counts in umbilical cord blood. Dietary LSE supplementation significantly increased (p < 0.05) the levels of prolactin (PRL) and growth hormone (GH), and the content of interleukin 2 (IL-2) in umbilical cord serum. Moreover, immunoglobulin A (IgA) and immunoglobulin M (IgM) in the colostrum were increased with PE supplementation (p < 0.05). In conclusion, dietary LSE supplementation in late-pregnancy sows could improve reproductive performance and colostrum quality, and could also regulate the levels of reproductive hormone in umbilical cord serum.

Escherichia coli K88 activates NLRP3 inflammasome-mediated pyroptosis in vitro and in vivo

Pyroptosis induced by lipopolysaccharide (LPS) has an obvious impact on intestinal inflammation and immune regulation. Enterotoxigenic Escherichia coli (ETEC) K88 has been proved to induce inflammatory responses in several models, but whether E. coli K88 participates in the same process of pyroptotic cell death as LPS remains to be identified. We conducted a pilot experiment to confirm that E. coli K88, instead of Escherichia coli O157 and Salmonella typhimurium, promotes the secretion of interleukin-1 beta (IL-1β) and interleukin-18 (IL-18) in macrophages. Further experiments were carried out to dissect the molecular mechanism both in vitro and in vivo. The Enzyme-Linked Immunosorbent Assay (ELISA) results suggested that E. coli K88 treatment increased the expression of pro-inflammatory cytokines IL-18 and IL-1β in both C57BL/6 mice and the supernatant of J774A.1 cells. Intestinal morphology observations revealed that E. coli K88 treatment mainly induced inflammation in the colon. Real-time PCR and Western blot analysis showed that the mRNA and protein expressions of pyroptosis-related factors, such as NLRP3, ASC, and Caspase1, were significantly upregulated by E. coli K88 treatment. The RNA-seq results confirmed that the effect was associated with the activation of NLRP3, ASC, Caspase1, GSDMD, IL-18, and IL-1β, and might also be related to inflammatory bowel disease and the tumor necrosis factor pathway. The pyroptosis-activated effect of E. coli K88 was significantly blocked by NLRP3 siRNA. Our data suggested that E. coli K88 caused inflammation by triggering pyroptosis, which provides a theoretical basis for the prevention and treatment of ETEC in intestinal infection.

Pyrroloquinoline quinone supplementation attenuates inflammatory liver injury by STAT3/TGF-β1 pathway in weaned piglets challenged with lipopolysaccharide

This study is aimed to evaluate the effect and underling mechanism of dietary supplementation with pyrroloquinoline quinone (PQQ) disodium on improving inflammatory liver injury in piglets challenged with lipopolysaccharide (LPS). A total of seventy-two crossbred barrows were allotted into four groups as follows: the CTRL group (basal diet + saline injection); the PQQ group (3 mg/kg PQQ diet + saline injection); the CTRL + LPS group (basal diet + LPS injection) and the PQQ + LPS group (3 mg/kg PQQ diet + LPS injection). On days 7, 11 and 14, piglets were challenged with LPS or saline. Blood was sampled at 4 h after the last LPS injection (day 14), and then the piglets were slaughtered and liver tissue was harvested. The results showed that the hepatic morphology was improved in the PQQ + LPS group compared with the CTRL + LPS group. PQQ supplementation decreased the level of serum inflammatory factors, aspartate aminotransferase and alanine transaminase, and increased the HDL-cholesterol concentration in piglets challenged with LPS; piglets in the PQQ + LPS group had lower liver mRNA level of inflammatory factors and protein level of α-smooth muscle actin than in the CTRL + LPS group. Besides, mRNA expression of STAT3/TGF-β1 pathway and protein level of p-STAT3(Tyr 705) were decreased, and mRNA level of PPARα and protein expression of p-AMPK in liver were increased in the PQQ + LPS group compared with the CTRL + LPS group (P < 0·05). In conclusion, dietary supplementation with PQQ alleviated inflammatory liver injury might partly via inhibition of the STAT3/TGF-β1 pathway in piglets challenged with LPS.

Dietary Supplementation of Tannins: Effect on Growth Performance, Serum Antioxidant Capacity, and Immunoglobins of Weaned Piglets-A Systematic Review with Meta-Analysis

In recent years, the swine industry has witnessed the withdrawal of antibiotics and continuous regulation of zinc and copper oxides in the early-life nutrition of piglets. Due to this development, alternative additives from plant sources have been extensively explored. Therefore, this study's objective was to evaluate the effect of dietary supplementation with tannins on weaned piglets' growth performance, serum antioxidant capacity, and serum immune status using a systematic review and meta-analysis approach. A total of 16 studies with parameters of interest were deemed eligible after a two-step screening process following a comprehensive literature search in the scientific databases of Web of Science, Scopus, ScienceDirect, PubMed, and Google Scholar. The inclusion criteria were mainly (1) studies involving basal diet supplemented with tannins and (2) studies with the quantification of tannin doses, while the exclusion criteria were (1) studies with pre- and post-weaning pigs and (2) challenged studies. Applying the random-effects models, Hedges' g effect size of supplementation with tannins was calculated using R software to determine the standardized mean difference (SMD) at a 95% confidence interval. Sub-group analysis and meta-regression further explored heterogeneity (PSMD < 0.05, I2 > 50%, n ≥ 10). Supplementation with tannins reduced the feed conversion ratio (p < 0.01) but increased the final body weight (p < 0.01) of weaned piglets. Chestnut and grape seed proanthocyanidin tannin sources yielded higher effects on growth performance. In addition, meta-regression models indicated that tannin dosage and supplementation duration were directly associated with tannins' effectiveness on productive performance. In the serum, the concentration of glutathione peroxidase, superoxide dismutase, and total antioxidant capacity were elevated (p < 0.01) in response to tannin supplementation, whereas malondialdehydes was reduced (p < 0.01). Likewise, increased immunoglobin M and G levels (p < 0.01) were detected. In conclusion, dietary supplementation with tannins, particularly with chestnut and grape seed proanthocyanidins, increases the productivity of weaned piglets. At the same time, it is a possible nutritional strategy to mitigate oxidative stress and stimulate gut health. Thus, supplementing chestnut and grape seed proanthocyanidin tannins in the early phase of swine production could be used to alleviate the incidence of diarrhea.

Alternatives to antibiotics in pig production: looking through the lens of immunophysiology

In the livestock production system, the evolution of porcine gut microecology is consistent with the idea of "The Hygiene Hypothesis" in humans. I.e., improved hygiene conditions, reduced exposure to environmental microorganisms in early life, and frequent use of antimicrobial drugs drive immune dysregulation. Meanwhile, the overuse of antibiotics as feed additives for infectious disease prevention and animal growth induces antimicrobial resistance genes in pathogens and spreads related environmental pollutants. It justifies our attempt to review alternatives to antibiotics that can support optimal growth and improve the immunophysiological state of pigs. In the current review, we first described porcine mucosal immunity, followed by discussions of gut microbiota dynamics during the critical weaning period and the impacts brought by antibiotics usage. Evidence of in-feed additives with immuno-modulatory properties highlighting probiotics, prebiotics, and phytobiotics and their cellular and molecular networking are summarized and reviewed. It may provide insights into the immune regulatory mechanisms of antibiotic alternatives and open new avenues for health management in pig production.

Cutting-edge knowledge on the roles of phytobiotics and their proposed modes of action in swine

With the ban on antibiotics in the swine industry, the exploration of alternative options has highlighted phytobiotics as a promising substitute for antibiotic growth promoters, aiming to foster a more sustainable swine industry. Phytobiotics are non-nutritive natural bioactive components derived from plants that offer numerous health benefits. They exhibit antioxidative, antimicrobial, and anti-inflammatory effects. Phytobiotics can be utilized in various forms, including solid, dried, ground, or as extracts, either in crude or concentrated form. They are characterized by low residual levels, a lack of resistance development, and minimal adverse effects. These qualities make phytobiotics an attractive choice for enhancing health and productivity in swine, presenting them as a viable alternative to antibiotics. While there is a general understanding of the effects of phytobiotics, there is still a need for detailed information regarding their effectiveness and mechanisms of action in practical settings. Therefore, the purpose of this mini review was to summarize the current knowledge supporting the roles of phytobiotics and their proposed modes of action, with a specific focus on swine.

Development of an amoxicillin-radix scutellaria extract formulation and evaluation of its pharmacokinetics in pigs

BACKGROUND

A new antibacterial compound powder of amoxicillin (AMO)/Radix Scutellaria extract (RSE) was developed, and its pharmacokinetics were determined in pigs following oral administration.

RESULTS

The MIC ranges of AMO against Escherichia coli, Staphylococcus aureus and Streptococcus were 1-8 μg/mL, 0.5-4 μg/mL and 0.5-64 μg/mL, respectively. The MIC ranges of RSE against E. coli, S. aureus, and Streptococcus were greater than 2.5 mg/mL, 0.156-2.5 mg/mL, and greater than 2.5 mg/mL, respectively. For S. aureus, the combined drug susceptibility test showed that AMO and RSE had an additive or synergistic effect. The results of compatibility test, the excipient screening test and the drug quality control test showed that the formulation had stable quality and uniform properties under the test conditions. Two studies were conducted to investigate the pharmacokinetics of the compound product in pigs. First, the pharmacokinetics of the AMO-RSE powder were compared with those of their respective single products. The results showed no significant change in the main pharmacokinetic parameters when either component was removed from the compound formulation; thus, AMO and RSE have no pharmacokinetic interaction in pigs. Second, pigs were orally administered three different doses of AMO-RSE powder. The Cmax and AUC increased proportionally with increasing p.o. dose; thus, the λz, t1/2λ, MRT, and Tmax were unchanged for the doses of 10, 20, and 30 mg/kg AMO and the doses of 5, 10, and 15 mg/kg BCL, showing that AMO/baicalin in AMO-RSE powder showed linear pharmacokinetic characteristics in pigs.

CONCLUSIONS

The combined drug sensitivity test of AMO and RSE against S. aureus showed that the combination was additive or synergistic. Pharmacokinetic studies indicated that AMO and BCL do not interfere with each other in pigs when used in a compound formulation. The pharmacokinetic parameters remained unchanged regardless of the dose for p.o. administration, indicating linear pharmacokinetic properties over the tested dose range. The quality of the AMO-RSE powder was good and stable, providing a foundation for its clinical application in veterinary medicine. Further bioavailability, PK/PD and clinical trials are still needed to determine the final dosage regimen.

Pyrroloquinoline quinone regulates glycolipid metabolism in the jejunum via inhibiting AMPK phosphorylation of weaned pigs

Maintenance of intestinal metabolic function is important for optimal growth performance in post-weaning pigs. This study aimed to evaluate the effect of pyrroloquinoline quinone (PQQ) on maintaining intestinal glycolipid metabolism in weaned pigs. Seventy-two Duroc × Landrace × Yorkshire crossbred pigs were divided into two groups: pigs fed a basal diet (CTRL group) and pigs fed a basal diet supplemented with 3.0 mg kg^-1 PQQ (PQQ group). On d 14, serum was harvested from six pigs per group and the pigs were slaughtered to sample jejunal tissue. Compared with the CTRL group, pigs in the PQQ group had increased average daily gain (P < 0.05), decreased feed : gain (P < 0.05) and tended to have a reduced diarrhea ratio (P = 0.057). Jejunal villus height and villus height/crypt depth ratio were increased, and the crypt depth was decreased in the PQQ group (P < 0.01). The proteomics results showed that PQQ supplementation acted on three metabolic pathways, type I diabetes mellitus, the pancreatic secretion pathway and immune-related signalling. Compared with the CTRL group, PQQ supplementation increased (P < 0.05) serum insulin and jejunal mucosal pyruvate, triglyceride, total cholesterol and low-density lipoprotein cholesterol in the pigs. Jejunal mucosal lactic dehydrogenase and high-density lipoprotein cholesterol levels in the pigs were decreased by PQQ supplementation (P < 0.05). In addition, PQQ supplementation reduced glucose transporter 5 and phosphorylated-AMP-activated protein kinase expression in the jejunal mucosa of the pigs (P < 0.05). In conclusion, dietary supplementation with PQQ improved the growth performance and jejunal morphology and regulated glycolipid metabolism via inhibiting AMPK phosphorylation in weaned pigs.

Gama-aminobutyric acid (GABA) alleviates hepatic inflammation via GABA receptors/TLR4/NF-κB pathways in growing-finishing pigs generated by super-multiparous sows

The offspring of super-multiparous sows face problems such as decreased growth performance, poor meat quality and even diseases in animal husbandry. Gama-aminobutyric acid (GABA) has long been known to promote growth and suppress inflammation, but little is known about the mechanisms. A total of 72 growing-finishing pigs from the 8th generation were randomly allotted to 2 groups with 6 replicates per treatment to receive a corn–soybean basal diet or the basal diet supplemented 20 mg/kg GABA for 60 d. After the animal-trial period, samples of serum and liver were collected for further analysis. Additionally, a lipopolysaccharide (LPS)-induced inflammatory model using HepG2 cells was established to explore the role of GABA on regulating hepatic inflammation. The results indicated that inflammatory cell infiltration occurs in the liver of progeny of super-multiparous sows, and dietary supplementation with GABA influenced liver morphology, increased activities of antioxidant enzymes and decreased the expression abundance of pro-inflammatory cytokines, including tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, in the liver of growing-finishing pigs (P < 0.05). In addition, GABA supplementation increased mRNA expressions of peroxisome proliferator-activated receptor γ (PPARγ) and GABA receptors (GABARs), and reduced the expression of toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling (P < 0.05). Additionally, an in vitro experiment demonstrated that GABA decreased the expressions of hepatic TLR4/NF-κB signaling via activating GABARs under LPS-stress (P < 0.05). In summary, liver injury may affect the growth performance of growing-finishing pigs by changing hepatic mitochondrial metabolism, the expression of pro-inflammatory cytokines and TLR4/NF-κB pathway and that GABA supplementation has a restorative effect by acting on GABARs.

Long-term administration of a commercial supplement enriched with bioactive compounds does not affect feed intake, health status, and growth performances in beef cattle

Abstract. Feed additives including natural bioactive compounds (BCs) in combination with vitamin E (VitE) and organic Se could mitigate animal stress associated with intensive livestock farming due to their anti-inflammatory and antioxidant properties. Yeast and yeast derivate are included in feed additives as probiotic products and digestion promoters. Scutellaria baicalensis is a source of bioactive compounds and has been tested in monogastrics, exhibiting many immunostimulating and hepato-protective activities. However, the literature lacks information regarding S. baicalensis effects on beef cattle performance and health status. The aim of the present study was to evaluate the impact on beef cattle's feed intake, health and oxidative status, and growth performances of the inclusion of a commercial supplement (CS) containing VitE, organic Se, yeast derivate, and S. baicalensis extract during the fattening and finishing period. A total of 143 Charolaise male cattle were allotted into 12 pens of 11–12 animals each and assigned to a control (463.9±21.48 body weight – BW) or a treated (469.8±17.91 BW) group. Each group included two replicates of three pens. The treated groups were supplemented with 20 gCSanimal-1d-1. Feed intake was measured monthly on a pen base during two consecutive days. Total mixed ration and fecal samples were collected at three time points (monthly, from November to February) and pooled by replicate for the analyses to monitor digestibility. Blood samples were individually collected at the beginning and at the end of the trial for oxidative status and metabolic profile determination. Final BW and carcass weight were individually recorded to calculate average daily gain, feed conversion ratio, and carcass yield. Similar feed digestibility between groups were observed during the whole experiment. Feed intake, growth performances, final body weight, average daily gain, feed conversion rate, oxidative status, and metabolic profile were not affected by the dietary inclusion of the tested CS indicating no detrimental effect of the treatment. Different doses of this product should be tested in the future in order to provide a more complete report on the product efficacy.

Pharmacological Applications and Action Mechanisms of Phytochemicals as Alternatives to Antibiotics in Pig Production

Antibiotics are widely used for infectious diseases and feed additives for animal health and growth. Antibiotic resistant caused by overuse of antibiotics poses a global health threat. It is urgent to choose safe and environment-friendly alternatives to antibiotics to promote the ecological sustainable development of the pig industry. Phytochemicals are characterized by little residue, no resistance, and minimal side effects and have been reported to improve animal health and growth performance in pigs, which may become a promising additive in pig production. This paper summarizes the biological functions of recent studies of phytochemicals on growth performance, metabolism, antioxidative capacity, gut microbiota, intestinal mucosa barrier, antiviral, antimicrobial, immunomodulatory, detoxification of mycotoxins, as well as their action mechanisms in pig production. The review may provide the theoretical basis for the application of phytochemicals functioning as alternative antibiotic additives in the pig industry.

Dietary Hermetia illucens Larvae Replacement Alleviates Diarrhea and Improves Intestinal Barrier Function in Weaned Piglets Challenged With Enterotoxigenic Escherichia coli K88

A high-quality protein substitute, Hermetia illucens (black soldier fly) larvae powder, is rich in protein and often used in animal feed. This study aimed to investigate the feasibility and optimal ratio of replacing fish meal with H. illucens larvae in weaned piglets and to demonstrate the effects on piglets' growth performance, intestinal microflora and immune performance. Forty-eight female weaned piglets were randomly classified into three groups. Each group consisted of eight pens (replicates), with two piglets per pen. Three groups containing different proportions of H. illucens larvae (0, 4, and 8%) were referred to as C, HI4, and HI8. We first designed a 28-day feeding experiment to detect growth performance; after that, the piglets were induced with oral gavage of enterotoxigenic Escherichia coli K88 (ETEC K88) and recording diarrhea on day 29 of the experiment. Samples were taken on the 32nd day to detect the effect of H. illucens larvae on the immune performance of the weaned piglets. H. illucens larvae replacement did not cause any obvious change in the growth performance nether in HI4 nor in HI8 of weaned piglets with 28 d feeding stage. H. illucens larvae could improve the intestinal health of weaned piglets by increasing the content of Lactobacillus and reducing the content of Streptococcus. Compared with C+K88 group, the diarrhea rate was attenuated for the H. illucens supplemented group. The integrity of ileum villi in HI4+K88 and HI8+K88 groups was better than that in C+K88 group, and the villi in C+K88 group were severely damaged. The expression of IL-10, Occludin and Claudin-3 in the intestinal mucosa of the HI4+K88 group and HI8+K88 group were significantly increased (P < 0.05), and the expression of TNF-α was significantly decreased (P < 0.05) compared with the C+K88 group. The results of immunoblotting also validated that the same ETEC K88 treatment of weaned piglets enhanced the expression of tight junction protein in the intestinal mucosa of the H. illucens addition group. ETEC-induced diarrhea will be reduced by the diet of weaned piglets containing H. illucens larvae, ameliorating the immune performance of piglets. Our results indicates that the optimal dosage of H. illucens replacement in weaned piglets is 4%.

Nano chitosan-zinc complex improves the growth performance and antioxidant capacity of the small intestine in weaned piglets

The present study was conducted to test the hypothesis that dietary supplementation with a nano chitosan-zinc complex (CP-Zn, 100 mg/kg Zn) could alleviate weaning stress in piglets challenged with enterotoxigenic Escherichia coli K88 by improving growth performance and intestinal antioxidant capacity. The in vivo effects of CP-Zn on growth performance variables (including gastrointestinal digestion and absorption functions and the levels of key proteins related to muscle growth) and the antioxidant capacity of the small intestine (SI) were evaluated in seventy-two weaned piglets. The porcine jejunal epithelial cell line IPEC-J2 was used to further investigate the antioxidant mechanism of CP-Zn in vitro. The results showed that CP-Zn supplementation increased the jejunal villus height and decreased the diarrhoea rate in weaned piglets. CP-Zn supplementation also improved growth performance (average daily gain and average daily feed intake), increased the activity of carbohydrate digestion-related enzymes (amylase, maltase, sucrase and lactase) and the mRNA expression levels of nutrient transporters (Na+-dependent glucose transporter 1, glucose transporter type 2, peptide transporter 1 and excitatory amino acid carrier 1) in the jejunum and up-regulated the expression levels of mammalian target of rapamycin (mTOR) pathway-related proteins (insulin receptor substrate 1, phospho-mTOR and phospho-p70S6K) in muscle. In addition, CP-Zn supplementation increased glutathione content, enhanced total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-px) activity, and reduced malondialdehyde (MDA) content in the jejunum. Furthermore, CP-Zn decreased the content of MDA and reactive oxygen species, enhanced the activity of T-SOD and GSH-px and up-regulated the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway-related proteins (Nrf2, NAD(P)H:quinone oxidoreductase 1 and haeme oxygenase 1) in lipopolysaccharide-stimulated IPEC-J2 cells. Collectively, these findings indicate that CP-Zn supplementation can improve growth performance and the antioxidant capacity of the SI in piglets, thus alleviating weaning stress.

Early supplementation with Lactobacillus plantarum in liquid diet modulates intestinal innate immunity through toll-like receptor 4-mediated mitogen-activated protein kinase signaling pathways in young piglets challenged with Escherichia coli K88

This study was conducted to investigate the effects of early supplementation during 4 to 18 d of age with Lactobacillus plantarum (LP) in liquid diets on intestinal innate immune response in young piglets infected with enterotoxigenic Escherichia coli (ETEC) K88. Seventy-two barrow piglets at 4 d old were assigned to basal or LP-supplemented liquid diet (5 × 1010 CFU·kg-1). On day 15, piglets from each group were orally challenged with either ETEC K88 (1 × 108 CFU·kg-1) or the same amount of phosphate-buffered saline. The intestinal mucosa, mesenteric lymph node (MLN), and spleen samples were collected on day 18. Here, we found that LP pretreatment significantly decreased the mRNA relative expression of inflammatory cytokines (interleukin [IL]-1β, IL-8, and tumor necrosis factor-α), porcine β-defensin 2 (pBD-2), and mucins (MUC1 and MUC4) in the jejunal mucosa in piglets challenged with ETEC K88 (P < 0.05). Moreover, LP significantly decreased the ileal mucosa mRNA relative expression of IL-8 and MUC4 in young piglets challenged with ETEC K88 (P < 0.05). Furthermore, the piglets of the LP + ETEC K88 group had lower protein levels of IL-8, secretory immunoglobulin A, pBD-2, and MUC4 in the jejunal mucosa than those challenged with ETEC K88 (P < 0.05). Besides, LP supplementation reduced the percentage of gamma/delta T cells receptor (γδTCR) and CD172a+ (SWC3+) cells in MLN and the percentage of γδTCR cells in the spleen of young piglets after the ETEC K88 challenge. Supplementation with LP in liquid diets prevented the upregulated protein abundance of toll-like receptor (TLR) 4, phosphorylation-p38, and phosphorylation-extracellular signal-regulated protein kinases in the jejunal mucosa induced by ETEC K88 (P < 0.05). In conclusion, LP supplementation in liquid diet possesses anti-inflammatory activity and modulates the intestinal innate immunity during the early life of young piglets challenged with ETEC K88, which might be attributed to the suppression of TLR4-mediated mitogen-activated protein kinase signaling pathways. Early supplementation with LP in liquid diets regulates the innate immune response, representing a promising immunoregulation strategy for maintaining intestinal health in weaned piglets.

Pyrroloquinoline quinone regulates the redox status in vitro and in vivo of weaned pigs via the Nrf2/HO-1 pathway

Background

Oxidative stress is a main cause of piglet gut damage and diarrhea. Pyrroloquinoline quinone (PQQ), is a novel redox cofactor with antioxidant properties. However, the effect and mechanism that PQQ supplementation decreases oxidative injury in weaned pigs is not understood. Therefore, the aim of this study is to confirm the effect of PQQ on regulating redox status in weaned pigs and the mechanism for antioxidant function by porcine intestinal epithelial cell line (IPEC-J2) challenged with H₂O₂.

Results

Experiment 1, 144 Duroc × Landrace × Yorkshire pigs (weaned at 28 d) were allocated to four groups: received a basal diet (control) and diets supplemented with 0.15%, 0.30% and 0.45% PQQ, respectively. On d 28, growth performance, diarrhea incidence and redox factors were measured. Experiment 2, IPEC-J2 were treated with or without PQQ in the presence or absence of H₂O₂ for indicated time points. Experiment 3, IPEC-J2 were transfected with or without Nrf2 siRNA, then treated according to Experiment 2. The cell viability, redox factors, protein of tight junctions and Nrf2 pathway were determined.

In vivo, PQQ supplementation demonstrated dose-related improvements in average daily gain, and gain to feed ratio (Linear P < 0.05). During d 0–28, compared to controls, 0.45% PQQ supplementation for pigs decreased diarrhea incidence and MDA content in liver and jejunum, and increased concentration of SOD in liver; 0.3% PQQ supplementation decreased ileal and liver MDA concentration; and 0.15% PQQ supplementation decreased ileal MDA concentration (P < 0.05). In vitro, compared to cells cultured with H₂O₂, pre-treatment with PQQ increased cell viability, tight junction proteins expression including ZO-1, ZO-2, Occludin and Claudin-1; and decreased ROS concentration and level of Caspase-3 (P < 0.05); as well as upregulated the ratio of Bcl-2 to Bax and protein expression of nuclear Nrf2, HO-1. Notably, Nrf2 knockdown by transfection with Nrf2 siRNA largely abrogated the positive effects of PQQ pretreatment on H₂O₂-induced intracellular changes.

Conclusions

PQQ administration attenuated oxidative stress in weaned pigs which is associated with activation of Nrf2/HO-1 pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-021-00595-x.

The Use of Chinese Skullcap (Scutellaria baicalensis) and Its Extracts for Sustainable Animal Production

Simple Summary

With the increasing pressure to address the problems of bacterial resistance and drug residues, medicinal herbs are gradually taking a more important role in animal production. Scutellaria baicalensis is a common and widely used Chinese medicinal herb. The main bioactive compounds in the plant are baicalein and baicalin. These compounds have many biological functions including anti-oxidation, antipyretic, analgesic, anti-inflammatory, antiallergic, antimicrobial, immunomodulatory, and antitumor effects. S. baicalensis and its extracts can effectively promote animal growth, improve the production performance of dairy cows, reduce the stress and inflammatory response, and have effective therapeutic effects on diseases caused by bacteria, viruses, and other pathogenic microorganisms. This paper summarizes the biological function of S. baicalensis and its application in sustainable animal production to provide a reference for future application of S. baicalensis and other medicinal herbs in animal production and disease treatment.

Abstract

Drugs have been widely adopted in animal production. However, drug residues and bacterial resistance are a worldwide issue, and thus the most important organizations (FAO, USDA, EU, and EFSA) have limited or banned the use of some drugs and the use of antibiotics as growth promoters. Natural products such as medicinal herbs are unlikely to cause bacterial resistance and have no chemical residues. With these advantages, medicinal herbs have long been used to treat animal diseases and improve animal performance. In recent years, there has been an increasing interest in the study of medicinal herbs. S. baicalensis is a herb with a high medicinal value. The main active compounds are baicalin and baicalein. They may act as antipyretic, analgesic, anti-inflammatory, antiallergenic, antimicrobial, and antitumor agents. They also possess characteristics of being safe, purely natural, and not prone to drug resistance. S. baicalensis and its extracts can effectively promote the production performance of livestock and treat many animal diseases, such as mastitis. In this review, we summarize the active compounds, biological functions, and applications of S. baicalensis in the production of livestock and provide a guideline for the application of natural medicines in the production and treatment of diseases.

Pyrroloquinoline Quinone Alleviates Jejunal Mucosal Barrier Function Damage and Regulates Colonic Microbiota in Piglets Challenged With Enterotoxigenic Escherichia coli

This study aimed to evaluate the effect of dietary supplementation with pyrroloquinoline quinone (PQQ) on gut inflammation and microbiota dysbiosis induced by enterotoxigenic Escherichia coli (ETEC). Twenty Duroc × Landrace × Yorkshire crossbred barrows were assigned to four groups: two E. coli K88 challenge groups and two non-challenge groups, each provided a basal diet supplemented with 0 or 3 mg/kg PQQ. On day 14, piglets were challenged with 10 mL 1 × 10⁹ CFU/mL of E. coli K88 or PBS for 48 h. The villus height (VH) and villus height/crypt depth (VCR) ratio of the E. coli K88-challenged group supplemented with PQQ was significantly reduced than in the non-supplemented challenge group (P < 0.05), while levels of jejunal zonula occludens-3 (ZO-3), diamine oxidase, secretory immunoglobulin A (SIgA), interleukin-10 (IL-10), and IL-22 proteins were higher (P < 0.05), as were the activities of glutathione peroxidase, total superoxide dismutase, and total antioxidant capability (P < 0.05). Moreover, PQQ supplementation alleviated an increase in levels of mucosal inflammatory cytokines and reduced the activity of nuclear factor-kappa B (NF-κB) pathway by E. coli K88 (P < 0.05). Gene sequencing of 16S rRNA showed dietary supplementation with PQQ in E. coli K88-challenged piglets attenuated a decrease in Lactobacillus count and butyrate, isobutyrate level, and an increase in Ruminococcus and Intestinibacter counts, all of which were observed in non-supplemented, challenge-group piglets. These results suggest that dietary supplementation with PQQ can effectively alleviate jejunal mucosal inflammatory injury by inhibiting NF-κB pathways and regulating the imbalance of colonic microbiota in piglets challenged with E. coli K88.