Dietary Citrus Flavonoids Improved Growth Performance and Intestinal Microbiota of Weaned Piglets via Immune Function Mediated by TLR2/NF-κB Signaling Pathway.

This study investigated the effects of citrus flavonoids (CF) and compared to antibiotics on piglet growth and gut health. Weaned piglets were fed either a basal diet (CON) or a basal diet supplemented with 75 mg/kg chlortetracycline (CTC), 20 mg/kg CF (CF1), 40 mg/kg CF (CF2), or 80 mg/kg CF (CF3). The CF group, especially CF3, exhibited improved growth performance; reduced diarrhea; significantly higher levels of serum growth factors, immunoglobulins, and anti-inflammatory cytokines; and significantly lower levels of pro-inflammatory factors and markers of intestinal barrier damage (P < 0.05). The intestinal mucosa proteins ZO-1 and occludin increased, while NF-κB and TLR2 decreased, correlating with CF dosage (P < 0.05). Furthermore, CF promoted a favorable balance in the gut microbiota, with an increased relative abundance of Bacteroidetes and Prevotella and decreased taxa Tenericutes and Clostridiales. Overall, CF enhanced piglet growth and gut health by modulating the TLR2/NF-κB pathway, offering a natural antibiotic alternative. The optimal dose of CF was 80 mg/kg.

Dietary tryptophan improves growth and intestinal health by promoting the secretion of intestinal ß-defensins against enterotoxigenic Escherichia coli F4 in weaned piglets.

Adequate dietary L-tryptophan (Trp) governs intestinal homeostasis in piglets. However, the defensive role of Trp in the diet against enterotoxigenic Escherichia coli F4 (K88) in pigs is still poorly understood. Here, sixty (6.15 ± 1.52 kg, 24-day-old, Duroc × Landrace × Yorkshire) weaned piglets were used for an E. coli F4 attack test in a 2 × 2 factorial design. The growth (ADG, ADFI, GH), immune factors (IL-10, IgA, IgG, IgM), Trp metabolite 5-HT, intestinal morphology (jejunal and colonic VH), mRNA expression of ß-defensins (jejunal BD-127, BD-119, ileal BD-1, BD-127), and abundance of beneficial microorganisms in the colon (Prevotella 9, Lactobacillus, Phascolarctobacterium, Faecalibacterium) were higher in the piglets in the HT (High Trp) and HTK (High Trp, K88) groups than in the LT (Low Trp) and LTK (Low Trp, K88) groups (P<.05), while FCR, diarrhea rate, diarrhea index, serum Trp, Kyn, IDO, D-LA, ET, and abundance of harmful microorganisms in the colon (Spirochaetes, Fusobacteria, Prevotella, Christensenellaceae R7) were lower in the HT and HTK groups than in the LT and LTK groups (P<.05). High Trp reduced the expression of virulence genes (K88 and LT) after E. coli F4 attack (P<.05). The IL-6, TNF-α was lower in the HTK group than in the LT, LTK group (P<.05). In short, a diet containing 0.35% Trp protected piglets from enterotoxigenic E. coli F4 (K88) via Trp metabolism promoting BD expression in the intestinal mucosa, which improved growth and intestinal health.

Dietary Taurine Improves Growth Performance and Intestine Health via the GSH/GSSG Antioxidant System and Nrf2/ARE Signaling Pathway in Weaned Piglets.

Early weaning of piglets was prone to increase reactive oxygen species, disrupt the redox balance, decrease antioxidant capacity, cause oxidative stress and intestinal oxidative damage, and lead to diarrhea in piglets. This research aimed to study dietary taurine (Tau) supplementation at a level relieving intestinal oxidative damage in early-weaned piglets. A total of 48 piglets were assigned to four groups of 12 individuals and fed a basal diet with 0.0% Tau (CON), 0.2% Tau (L-Tau), 0.3% Tau (M-Tau), or 0.4% Tau (H-Tau), respectively. The animal experiment lasted 30 days. The final weight, weight gain, average daily gain, and feed conversion rate increased with the increase in dietary Tau (Linear, p < 0.05; Quadratic p < 0.05), while the diarrhea index of piglets decreased with the increase in dietary Tau (Linear, p < 0.05). Serum malondialdehyde, nitric oxide (NO), D-lactose, and oxidized glutathione (GSSG) concentrations decreased with the increase in dietary Tau (Linear, p < 0.05). The O2•- and •OH clearance rate in serum, liver, and jejunum mucosa increased with the increase in dietary Tau (Linear, p < 0.05). Serum superoxide dismutase (SOD) activity, glutathione peroxidase (GPX) activity, catalase (CAT) activity, and peroxidase (POD) activity and total antioxidant capacity increased with the increase in dietary Tau (Linear, p < 0.05). The serum glutathione (GSH) concentration and the ratio of GSH to GSSG increased with the increase in dietary Tau (Linear, p < 0.05). The POD and glutathione synthase activity in the liver and jejunum mucosa increased with the increase in dietary Tau (Linear, p < 0.05). The mRNA abundances of HO-1 and GPX1 in the H-Tau group were higher than that in the L-Tau, M-Tau, and CON groups (p < 0.05). The mRNA abundances of SOD1 and Nrf2 in the M-Tau and H-Tau groups were higher than in the L-Tau and CON groups (p < 0.05). The mRNA abundance of SOD2 in the L-Tau, M-Tau, and H-Tau groups was higher than in the CON group (p < 0.05). The VH and the ratio of VH to CD of jejunum and ileum increased with the increase in dietary Tau (Linear, p < 0.05). The mRNA abundances of occludens 1 and claudin 1 in the H-Tau group were higher than that in the CON, L-Tau, and M-Tau (p < 0.05). The mRNA abundance of occludin in the L-Tau, M-Tau, and H-Tau groups was higher than that in CON (p < 0.05). The abundance of Firmicutes increased with the increase in dietary Tau (Linear, p < 0.05), while Proteobacteria and Spirochaetota decreased with the increase in dietary Tau (Linear, p < 0.05). Collectively, dietary supplementation of 0.3% and 0.4% Tau in feed could significantly improve the growth performance and enhance the antioxidant capacity of piglets.

Effect of High Efficiency Digestion and Utilization of Organic Iron Made by Saccharomyces cerevisiae on Antioxidation and Caecum Microflora in Weaned Piglets.

Organic iron is expected to replace inorganic iron used in diets as an iron source. Organic iron possesses high absorption efficiency and low fecal iron excretion. This study aims to study the effect of organic iron produced by Saccharomyces cerevisiae (yeast iron) on digestion, utilization, antioxidation and caecum microflora in weaned piglets. In total, 20 piglets that had been weaned after 28 days were divided into 4 groups, each of which followed a different basal diet. The basal diet of each of these 4 groups contained, respectively, 104 mg/kg iron (ferrous sulfate, CON), 84 mg/kg iron (yeast iron, LSC), 104 mg/kg iron (yeast iron, MSC) or 124 mg/kg iron (yeast iron, HSC). This experiment lasted 35 d. The apparent digestibility of iron in LSC, MSC and HMS was higher than that in CON (p < 0.01) and the fecal iron content in LSC, MSC and HMS was lower than that in CON (p < 0.01). Serum iron contents in LSC, MSC and HMS were higher than that in CON (p < 0.01). The iron contents of the heart, lungs, liver, kidney and left gluteus muscle in the MSC and HMS groups were higher than that in CON and LSC (p < 0.05). Serum catalase, glutathione peroxidase, superoxide dismutase activity, superoxide anion, glutathione, hydroxyl free radical scavenging rate, total antioxidant capacity, and liver superoxide anion clearance rate and peroxidase in MSC and HMS were higher than that in CON and LSC (p < 0.05). The contents of nitric oxide and peroxide of the weaned piglets in MSC and HMS were lower than that in CON and LSC (p < 0.05). The abundance of Firmicutes, Blautia and Peptococcus in LSC, HSC and MSC was higher than that in CON (p < 0.01). The abundance of Lactobacillus in CON and LSC was higher than that in MSC and HSC (p < 0.01). The abundance of Acinetobacter, Streptococcus and Prevotella in LSC, MSC and HSC was lower than that in CON (p < 0.01). The results suggested that a diet containing 84 mg/kg iron of yeast iron has the same effect as a diet containing 104 mg/kg iron of ferric sulfate, and that a diet containing 104 or 124 mg/kg iron of yeast iron is superior to a diet containing 104 mg/kg iron of ferric sulfate.

Effects of Multi-Bacteria Solid-State Fermented Diets with Different Crude Fiber Levels on Growth Performance, Nutrient Digestibility, and Microbial Flora of Finishing Pigs.

This study aimed to investigate the effects of multi-bacteria solid-state fermented diets with different crude fiber (CF) levels on growth performance, nutrient digestibility, and microbial flora of finishing pigs. The multi-bacteria solid-state fermented diets were made up of Lactobacillus amylovorus, Enterococcus faecalis, Bacillus subtilis, and Candida utilis. According to a 2 (factors) × 2 (levels) design, with the two factors being multi-bacteria solid-state fermentation (fed non-fermented diet or multi-bacteria fermentation) or CF levels (fed a basal diet containing 2.52% CF or 7.00% CF), a total of 36 finishing pigs (70.80 ± 5.75 kg) were divided into 4 treatments with 9 barrows per group: (1) pigs fed a diet containing 7.00% CF (HF), (2) pigs fed a multi-bacteria fermentation diet containing 7.00% CF (HFM), (3) pigs fed a diet containing 2.52% CF (LF), and (4) piglets fed a multi-bacteria fermentation diet containing 2.52% CF (LFM). This experiment lasted 28 days. The multi-bacteria solid-state fermented diet increased the backfat thickness (p < 0.05) and apparent total tract nutrient digestibility (ATTD) of CF, neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), 8 amino acids (Trp, Asp, Gly, Cys, Val, Met, Ile, and Leu), total essential amino acids (EAA), total non-essential amino acids (NEEA), and total amino acids (TAA) (p < 0.05). Multi-bacteria solid-state fermented diet increased serum concentrations of HDL-c, ABL, TP, and GLU, the serum enzyme activities of GSH-Px, T-AOC, SOD, and CAT (p < 0.05), the relative abundance of Lactobacillus, Oscillospira, and Coprococcus (p < 0.05), and the abundance of YAMINSYN3-PWY, PWY-7013, GOLPDLCAT-PWY, ARGORNPROST-PWY, and PWY-5022 pathways (p < 0.05). The multi-bacteria solid-state fermented diet reduced the digestion amount of CF, NDF, and ADF (p < 0.05), the serum concentrations of TC, TG, LDL-c, BUN, and MDA (p < 0.05), the relative abundance of Streptococcaceae (p < 0.05), and the abundance of PWY-6470, PWY0-862, HSERMETANA-PWY, LACTOSECAT-PWY, MET-SAM-PWY, PWY-6700, PWY-5347, PWY0-1061, and LACTOSECAT-PWY pathways (p < 0.05). The high-fiber diet increased average daily feed intake (p < 0.05), the serum concentrations of TC, TG, LDL-c, BUN, and MDA (p < 0.05), the relative abundance of Clostridiaceae_Clostridium and Coprococcus (p < 0.05), and the abundance of TCA-GLYOX-BYPASS, GLYCOLYSIS-TCA-GLYOX-BYPASS, and PWY-6906 pathways (p < 0.05). The high-fiber diet reduced chest circumference (p < 0.05) and ATTD of ether extract (EE), CF, NDF, ADF, Ca, CP, 18 amino acids (Trp, Thr, Val, Met, Ile, Leu, Phe, Lys, His, Arg Asp, Ser, Glu, Gly, Ala, Cys, Tyr, and Pro), EAA, NEAA, and TAA (p < 0.05). The high-fiber diet also reduced the serum concentrations of HDL-c, TP, ABL, and GLU, the serum enzyme activities of T-AOC, GSH-Px, SOD, and CAT (p < 0.05), and the relative abundance of Akkermansia and Oscillospira (p < 0.05). There was no significant effect of the interaction between multi-bacteria fermentation and dietary CF levels, except on the digestion amount of CF (p < 0.05). The 7.00% CF had a negative effect on the digestion of nutrients, but multi-bacteria solid-state fermentation diets could relieve this negative effect and increase backfat thickness. High-fiber diets and multi-bacteria solid-state fermentation improved the diversity and abundance of fecal microorganisms in finishing pigs.