The objective was to investigate the effects of STTD Ca and P levels on performance, deposition of Ca and P, and bone development at STTD Ca: STTD P of 1.2:1; this study also aimed to determine the optimal STTD Ca and STTD P concentrations at the ratio of 1.2:1. A total of 144 weaned pigs (7.23 ± 0.92 kg) were randomly assigned to 6 treatments with 6 replicate pens. Two phases (7-11kg and 11-25kg) were included. The ratio of STTD Ca and P (1.2:1) remained consistent in each diet. The 6 graded STTD Ca and P were 1) 0.216% and 0.180% (LCAP); 2) 0.312% and 0.260%; 3) 0.408% and 0.340% (MCAP); 4) 0.504% and 0.420%; 5) 0.600% and 0.500%; 6) 0.696% and 0.580% (HCAP). Diets within each phase were isocaloric and isonitrogenous. Compared to group 1 (LCAP), F:G was lower (P < 0.05) in group 5 and 6 during phase 1; F:G was lower (P < 0.05) in group 2-6 during phase 2. As dietary Ca and P levels increase, plasma Ca (P = 0.101), PTH (P <0.001), calcitonin (CT; P <0.001), and vitamin D3 (VD3; P <0.05) increase, whereas plasma P declines (P = 0.105). Both bone mineral density and content increased with elevated dietary Ca and P (P < 0.05). The expression of FN1, COL3A1, COL1A2 and ITGβ2 were upregulated (P < 0.05) in the MCAP compared with the LCAP and HCAP. When the optimal F:G was achieved in phase 1, the STTD Ca and STTD P were 0.36% and 0.30%, respectively; when in phase 2, the STTD Ca and STTD P were 0.31% and 0.26%, respectively. When the dietary STTD Ca:STTD P ratio was at 1.2:1, the optimal levels of STTD Ca and STTD P were 0.36% and 0.30%, respectively, during Phase 1; and 0.31% and 0.26%, respectively, during Phase 2. The estimated breakpoints derived from the present study was lower than the NRC (2012) recommendation, indicating that under STTD Ca:STTD P ratio of 1.2:1, the requirements for Ca and P can be further reduced, thereby improving the utilization efficiency and conserving Ca and P resources.

This experiment aimed to study the effects of dietary supplementation with biosynthetic reuterin (RT) from Escherichia coli cells on the growth performance and intestinal health of pigs. A total of 72 pigs (Duroc × Landrace × Yorkshire, 21 d old, 5.7 ± 0.3 kg weight) were randomly divided into basal diet group (CON), basal diet supplemented with 5 × 1010 colony-forming unit (CFU)/kg Lactobacillus reuteri group (LR), and basal diet supplemented with 50 mg/kg reuterin group (RT) with 6 pens (4 pigs per pen) per group for a 14-d period. One piglet was randomly selected from each pen on the 15th d for sampling. The results showed that the addition of RT to the diet significantly improved the growth performance of piglets, specifically increasing average daily gain (ADG; P= 0.004), and reduced diarrhea rate (P = 0.012), improved the intestinal morphology by significantly increasing villus height and the villus height to crypt depth ratio (P < 0.05), and enhanced intestinal barrier and immune functions by upregulating the expression of related genes (ZO1, MUC1, pBD2, and PR39, P < 0.05). Simultaneously, RT upregulated TLR gene expression and activated the MAPK signaling pathway (P < 0.05). Combined analysis of microbiome and non-targeted metabolomics showed that RT improved metabolism by affecting the relative abundance of Phascolarctobacterium succinatutens YIT12067 (known for succinate production and impacting energy metabolism) and Holdemanella (implicated in carbohydrate metabolism and immune modulation) in pigs (P < 0.05). In addition, RT significantly reduced the deposition of intestinal collagen (P < 0.05). In conclusion, this study demonstrated that biosynthetic RT effectively improved the growth and intestinal health of pigs, which may provide some theoretical basis for the RT production as a feed additive.

Abstract Background Weaning piglets are highly susceptible to enterotoxigenic Escherichia coli (ETEC) infections, which can cause intestinal barrier function dysfunction and death. However, there is still a lack of efficient, economical, and safe nutritional interventions. This study aimed to investigate the effects of combining butyrate with niacin on intestinal barrier function repair and resistance to ETEC infection in weaned piglets. In this study, two 14-d animal experiments were designed to observe the optimal butyrate-to-niacin ratio and assess their responses to the ETEC challenge. Results Supplementation with butyrate and niacin at a ratio of 100:2 (2,000 mg/kg butyrate and 40 mg/kg niacin, BN2) increased the average daily gain (ADG) and reduced the diarrhea incidence. We also observed an increase in the levels of nicotinamide adenine dinucleotide (NAD) in the colon of weaned piglets. Notably, BN2 promoted amino acid anabolism in the colon and enhanced glycolysis and the tricarboxylic acid (TCA) cycle by increasing the acetylation of key enzymes in the TCA. Furthermore, BN2 enhanced the expression of indispensable genes for the colonic mucosal barrier, including antimicrobial peptides such as porcine β defensin 1 (pBD1), porcine β defensin 2 (pBD2), and proline-arginine rich 39-amino acid peptide (PR39), tight junction proteins, and improved colonic microbiome composition. Based on these findings, we found that BN2 alleviated growth restriction and diarrhea, and modulated the expression of antimicrobial peptides, tight junction proteins, and cytokines to reduce colonic barrier function dysfunction in weaned piglets challenged with ETEC. Mechanistically, we confirmed that BN2 elevated the protein expression of acetylation of histone 3 lysin 27 (H3K27ac) and enhanced the binding of acH3K27 to the promoter regions of pBD1 and PR39. Conclusions Supplementation with BN2 improved growth performance, supported colonic barrier function repair, and enhanced disease resistance in weaned piglets challenged with ETEC. This offers new insights into nutritional strategies for intestinal barrier function repair of piglets infected with ETEC.

Weaning stress leads to intestinal dysfunction and impaired growth performance and intestinal development in piglets. This study aims to investigate the effects of Lactobacillus reuteri LR1 on growth performance and amino acid metabolism in the gut–liver axis of weaned piglets. A total of 48 weaned piglets (Duroc × Landrace × Yorkshire, 21 days old) were randomly assigned to the CON group (fed a basal diet) and the LR1 group (fed the basal diet supplemented with 5 × 1010 CFU/kg of Lactobacillus reuteri LR1) with six pens per group and 4 piglets each pen. The results demonstrated that LR1 significantly increased average daily gain (ADG), average daily feed intake (ADFI), and final body weight (p < 0.05). Additionally, LR1 significantly enhanced the villus height of the ileum (p < 0.05) and upregulated the expression of SLC6A19 in the jejunum, as well as SLC6A19, SLC7A1, and SLC38A9 in the ileum (p < 0.05). Amino acid analysis revealed that LR1 elevated the serum concentrations of glycine and hydroxyproline, along with increased taurine in the liver. Masson staining indicated LR1 reduced ileum fiber deposition, with COL3A1 identified as a key component. Furthermore, untargeted metabolomic analysis identified 27 amino acid-related differential metabolites and 11 significantly up-regulated in the plasma of the hepatic portal vein, including L-asparagine, L-citrulline, His-Cys, N-acetyltryptophan, 4-hydroxy-l-isoleucine, Gly-Arg, creatine, ornithine, ectoine, 3-methyl-l-histidine, and stachydrine. Correlation analysis suggested that COL1A2 and COL3A1 were closely associated with these metabolic changes. Overall, these findings suggest that LR1 supplementation promotes growth, improves intestinal morphology, reduces fiber deposition, and enhances amino acid metabolism in the gut–liver axis of weaned piglets.

Selenium-enriched yeast (SeY), a high-quality organic source of selenium, enhances antioxidant activity and intestinal health in swine. This study aims to evaluate the effects of varying dietary SeY levels on intestinal morphology, epithelial mucus production, antioxidant activity, and colonic bacterial communities in growing-finishing pigs. Thirty 90-day-old Duroc×Landrace×Yorkshire growing-finishing pigs (average body weight of 54.37±2.13 kg) were randomly assigned to five treatment groups. The control group (CON) was fed a basal diet, while the other four groups were fed the basal diet supplemented with SeY at 0.3, 1, 3, and 5 mg/kg, respectively, for an 80-day of feeding trial. The results showed that the addition of SeY at 0.3 mg/kg increased villus height, villus height/crypt ratio, and mucus production in the ileum, as evidenced by the increase in goblet cell number and mucus thickness (P < 0.05). Furthermore, 0.3 mg/kg SeY up-regulated the mRNA expression levels of the MUC-1, claudin-1, occludin, and ZO-1 genes (P < 0.05). In contrast, high-dose SeY at 5 mg/kg resulting in damage to mucosal morphology. Ileal antioxidant activity of SOD and GSH-Px, and jejunal mRNA expression of GPX-1 and GPX-4, were higher in response to SeY (P < 0.05). Faecal Se excretion increased in SeY groups in a dose-dependent manner (P < 0.05). SeY led to a significant difference in beta diversity among treatment groups (P = 0.002) and led to a significant decrease in the concentrations of isobutyric and isovaleric acids when compared to the control group (P < 0.05). The acetate, propionate, butyrate, and total short-chain fatty acids were positively correlated with the biomarker genera Agathobacter (SeY at 0.3mg/kg), while isobutyrate and isovalerate were negatively correlated with biomarker genera Lactobacillus (SeY at 0.3mg/kg) (P < 0.05). Faecal accumulation of Se was positively correlated with the biomarker genera Alloprevotella (SeY at 3mg/kg) and Prevotellaceae_UCG-001 (SeY at 5mg/kg) and was negatively correlated with biomarker genera Agathobacter (SeY at 0.3mg/kg), Bacteroides (CON), and Faecalibacterium (CON) (P < 0.05). In conclusion, SeY doses of 0.3 mg/kg have beneficial effects on intestinal health, whereas prolonged SeY doses up to 5 mg/kg may compromise the intestinal mucus function in growing-finishing pigs.

Background Butyrate is the primary energy substrate in the colon, whereas niacin can enhance energy metabolic flux by increasing nicotinamide adenine dinucleotide (NAD) synthesis. Therefore, this study aimed to investigate the effects of combining butyrate with niacin on colonic metabolism and resistance to enterotoxigenic Escherichia coli (ETEC) infection in weaned piglets. In this study, two animal experiments were designed to observe the optimal butyrate-to-niacin ratio and assess their responses to the ETEC challenge. Results Supplementation with Butyrate and niacin at a ratio of 100:2 (2000 mg/kg butyrate and 40 mg/kg niacin, BN2) increased the average daily gain (ADG) and reduced the diarrhea incidence. We also observed an increase in the levels of NAD in the colon of weaned piglets. Notably, BN2 promoted amino acid anabolism in the colon and enhanced glycolysis and the tricarboxylic acid (TCA) cycle by increasing the acetylation of key enzymes in the TCA. Furthermore, BN2 enhanced the expression of indispensable genes for the colonic mucosal barrier, including antimicrobial peptides (porcine β defensin 1, pBD1; porcine β defensin 2, pBD2; and proline-arginine rich 39-amino acid peptide, PR39), tight junction proteins, and improved colonic microbiome composition. Based on these findings, we found that BN2 alleviated growth restriction and diarrhea, and modulated the expression of antimicrobial peptides, tight junction proteins, and cytokines to reduce colonic barrier function dysfunction in weaned piglets challenged with ETEC. Mechanistically, we confirmed that BN2 elevated the protein expression of acetylation of histone 3 lysin 27 (H3K27ac) and enhanced the binding of acH3K27 to the promoter regions of pBD1 and PR39. Conclusions Supplementation with BN2 improved growth performance, supported colonic health, and enhanced disease resistance in weaned piglets challenged with ETEC. This offers new insights for nutrients-based strategies against ETEC infection.

Marine bacteria are an untapped resource for exopolysaccharides (EPS) with broad potential applications in biomedicine, bioremediation, and food industries. However, industrial utilization remains limited due to low yields and strain-specific variability. This study explores seven novel marine bacterial strains (Limnobacter alexandrii LZ-4, Nioella ostreopsis Z7-4, Mesorhizobium alexandrii Z1-4, Marinobacter shengliensis subsp. Alexandrii LZ-6, Marinobacter alexandrii LZ-8, Memelialla alexandrii LZ-28, and Sulfitobacter alexandrii AM1-D1) isolated from marine dinoflagellate microbiota. A genome-guided, high-throughput fermentation strategy was employed to optimize EPS production. Genomic analysis identified distinct EPS biosynthesis pathways (e.g., alginate and cellulose synthesis) and key genes (algA/C/D, bcsB, and epsE/H/J) involved in both the polymerization and the secretion of EPS. High-throughput screening under 50 fermentation conditions revealed sucrose and fructose as optimal carbon sources, with alkaline pH (7-9) significantly enhancing EPS yields (up to 159.6 µg/mL). Strain-specific optimization demonstrated that LZ-4 and Z7-4 achieved maximal EPS production at 28°C, whereas LZ-8 exhibited a high EPS production at 37°C. The study underscores the synergy between genomic insights and systematic screening, offering a scalable framework for rapid strain optimization. These findings pave the way for sustainable EPS bioproduction, reducing reliance on synthetic polymers and advancing industrial biotechnology in alignment with circular bioeconomy goals.IMPORTANCEThis study integrates genomic analysis with high-throughput fermentation to optimize exopolysaccharide (EPS) production in seven novel marine bacterial strains. By identifying key EPS biosynthesis genes and pathways, we tailored fermentation conditions using sucrose and alkaline pH, achieving yields up to 159.6 µg/mL. Strain-specific optimizations revealed significant enhancements in EPS production, highlighting the potential for sustainable industrial applications. This work bridges ecological insights with bioprocessing, offering a scalable framework for efficient EPS production that reduces reliance on synthetic polymers, advancing circular bioeconomy goals. The findings underscore the importance of marine microbial resources in biotechnology.

The objective of this study was to investigate the effects of replacing fishmeal with H. illucens larval meal on the colonic immune homeostasis in weaned piglets in enterotoxigenic Escherichia coli (ETEC)-challenged pig housing. Seventy-two weaned piglets, aged 28 days, were randomly divided into three groups for dietary treatment: the basal diet (negative control, NC), the positive control diet (PC) supplemented with 1445 mg zinc/kg zinc oxide in the basal diet, and the H. illucens larval meal complete replacement of fishmeal in the basal diet (HILM), for 28 days in ETEC-challenged pig housing. The results showed that the relative transcript abundances of ZO-1, pBD2, PR39, and PG1–5 were increased (p < 0.05) in pigs fed the HILM diet compared with those fed the NC diet. In addition, the HILM diet reduced (p < 0.05) the serum contents of IL-8 and increased (p < 0.05) the serum contents of IL-10 and IgG compared with the NC diet. In terms of the molecular mechanisms by which immune homeostasis is improved, the p-NF-κB/ NF-κB ratio and TLR2 protein expression in the colon were decreased (p < 0.05) in pigs fed the HILM diet compared with those fed the NC diet. Compared with the NC diet, the HILM diet reduced (p < 0.05) the protein expression of HDAC3 and HDAC7 in the colon of pigs. The SIRT1, acH3K9, and pH3S10 protein expressions in the colon were the greatest (p < 0.05) in pigs fed the HILM diet compared with the NC diet. HILM diets improved the colonic immune homeostasis in weaned piglets by enhancing the antimicrobial peptide expression, thereby mitigating ETEC challenges in pig housing. Mechanistically, HILM diets promote antimicrobial peptide expression through increased histone acetylation (acH3K9 and pH3S10).

Reuterin, a mixture of different forms of 3-hydroxypropanal (3-HPA), including HPA hydrate and HPA dimer, is an antimicrobial compound converted from glycerol by Lactobacillus reuteri and other strains. Although its antimicrobial function may be related to its interaction with thiol groups, its temperature stability and effect on the gut environment remain unclear. The present study evaluated the antimicrobial effects and activity of reuterin against Escherichia coli and Salmonella typhimurium. Utilization of a reliable in vitro gut microbiome fermentation system revealed that reuterin has a modulatory effect on the gut microbial community. Reuterin treatment completely inhibited H2 and NH3 production in the gut and significantly enhanced the synthesis of branched short-chain fatty acids. 16s rRNA sequencing indicated that reuterin promoted the growth of Proteobacteria and Bacteroidetes in the in vitro system and significantly modulated gut microbiota composition.

Background In the realm of swine production, optimizing body composition and reducing excessive fat accumulation is critical for enhancing both economic efficiency and meat quality. Despite the acknowledged impact of dietary calcium (Ca) and phosphorus (P) on lipid metabolism, the precise mechanisms behind their synergistic effects on fat metabolism remain elusive. Results Research observations have shown a decreasing trend in the percentage of crude fat in carcasses with increased calcium and phosphorus content in feed. Concurrently, serum glucose concentrations significantly decreased, though differences in other lipid metabolism-related indicators were not significant across groups. Under conditions of low calcium and phosphorus, there is a significant suppression in the expression of FABPs, CD36 and PPARγ in the jejunum and ileum, leading to inhibited intestinal lipid absorption. Concurrently, this results in a marked increase in lipid accumulation in the liver. Conversely, higher levels of dietary calcium and phosphorus promoted intestinal lipid absorption and reduced liver lipid accumulation, with these changes being facilitated through the activation of the CAMKK2/AMPK signaling pathway by high-calcium-phosphorus diets. Additionally, the levels of calcium and phosphorus in the diet significantly altered the composition of liver lipids and the gut microbiota, increasing α-diversity and affecting the abundance of specific bacterial families related to lipid metabolism. Conclusion The evidence we provide indicates that the levels of calcium and phosphorus in the diet alter body fat content and lipid metabolism by modulating the response of the gut-liver axis to lipids. These effects are closely associated with the activation of the CAMKK2/AMPK signaling pathway.

Selenium nanoparticles (SeNPs) are proposed as a safer and more effective selenium delivery system than sodium selenite (Na2SeO3). Here, we investigated the effects of replacing dietary Na2SeO3 with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of early-weaned piglets. Seventy-two piglets (Duroc × Landrace × Large Yorkshire) weaned at 21 d of age were divided into the control group (basal diet containing 0.3 mg Se/kg from Na2SeO3) and SeNPs group (basal diet containing 0.3 mg Se/kg from SeNPs) during a 14-d feeding period. The results revealed that SeNPs supplementation increased the average daily gain (P = 0.022) and average daily feed intake (P = 0.033), reduced (P = 0.056) the diarrhea incidence, and improved (P = 0.013) the feed conversion ratio compared with Na2SeO3. Additionally, SeNPs increased jejunal microvilli height (P = 0.006) and alleviated the intestinal barrier dysfunction by upregulating (P < 0.05) the expression levels of mucin 2 and tight junction proteins, increasing (P < 0.05) Se availability, and maintaining mitochondrial structure and function, thereby improving antioxidant capacity and immunity. Furthermore, metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis, secretion and action of parathyroid hormone, proximal tubule bicarbonate reclamation and tricarboxylic acid cycle. Moreover, SeNPs increased (P < 0.05) the abundance of Holdemanella and the levels of acetate and propionate. Correlation analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid metabolism. Overall, replacing dietary Na2SeO3 with biogenic SeNPs could be a potential nutritional intervention strategy to prevent early-weaning syndrome in piglets.

Post-weaning diarrhea (PWD) in piglets poses a significant challenge and presents a grave threat to the global swine industry, resulting in considerable financial losses and compromising the welfare of animals. PWD is commonly associated with gut homeostatic imbalance, including oxidative stress, excessive inflammation, and microbiota dysbiosis. Antibiotic use has historically been a common initiative to combat PWD, but concerns about the development of antibiotic resistance have led to increased interest in alternative strategies. Mitochondria are key players in maintaining cellular homeostasis, and their dysfunction is intricately linked to the onset and progression of PWD. Accumulating evidence suggests that targeting mitochondrial function using antioxidant nutrients, such as vitamins, minerals and polyphenolic compounds, may represent a promising approach for preventing and treating PWD. Moreover, nutrients based on antioxidant strategies have been shown to improve mitochondrial function, restore intestinal redox balance, and reduce oxidative damage, which is a key driver of PWD. The present review begins with an overview of the potential interplay between mitochondria and gut homeostasis in the pathogenesis of PWD in piglets. Subsequently, alternative strategies to prevent and treat PWD using antioxidant nutrients to target mitochondria are described and discussed. Ultimately, we delve into potential limitations and suggest future research directions in this field for further advancement. Overall, targeting mitochondria using antioxidant nutrients may be a promising approach to combat PWD and provides a potential nutrition intervention strategy for regulating gut homeostasis of weaned piglets.

[Objective]It aims to preliminarily reveal the effect of dietary supplementation with porcine Lactobacillus reuteri LR1 on the expression of intestinal extracellular matrix(ECM)in weaned piglets,providing references for the promotion and application of porcine LR1 in animal husbandry.[Method]One hundred and forty-four Duroc-Landrace-Yorkshire crossbred weaned piglets with similar body weights at 21 days of age were selected and randomly divided into three treatment groups,which were fed a basal diet(control group,CON group),a basal diet supplemented with 75 mg/kg of aureomycin and 100 mg/kg of quinol(antibiotic group,AO group),and a basal diet supplemented with 5×1010 CFU/kg of porcine L.reuteri LR1(porcine L.reuteri LR1 group,LR1 group),respectively,and each treatment group was divided into 8 pens for feeding,with 6 pigs in each pen.The experiment lasted for 42 days.On the 43rd day,one piglet from each group was randomly selected for slaughter,and samples of the duodenum(proximal),jejunum(middle),and ileum(distal)were taken for the detection of extracellular matrix related indicators such as intestinal collagen,fibronectin,tenascin and related regulatory factors.[Result]Masson staining observations showed that collagen fibers in the duodenum,jejunum and ileum all extended from the lower to the upper layers of the intestinal mucosa.Compared with the CON group,the collagen volume fraction of the duodenum decreased significantly in both the LR1 and AO groups(P<0.05),and the collagen volume fraction of the ileum also decreased significantly in the LR1 group(P<0.05).TMT high-throughput proteomics results showed that the ECM-receptor interaction pathway was one of the major differential protein-enriched pathways,and the expression of its differential proteins,COL1A2,COL4A2,COL6A1,ITGA1,and other ECM molecules,was significantly lower in the LR1 group than that in the CON group(P<0.05).In addition,the gene expression of COL1A2,COL3A1 and ITGβ2 in jejunum and ileum of LR1 and AO groups was significantly reduced compared with the CON group(P<0.05),and the gene expression of COL4A2,COL5A1,COL6A1,FN1,TNC,ITGα1 in jejunum,and ITGα1 in ileum was also significantly reduced in the LR1 group(P<0.05),but there were no significant effect on COL4A2,COL5A1,COL6A1,FN1 and TNC in ileum.Compared with the CON group(P<0.05),in the ileum of the LR1 and AO groups,the contents of Collagen I,Collagen Ⅱ,Collagen Ⅲ,Collagen Ⅳ,Collagen Ⅴ and Collagen Ⅵ significantly decreased;the gene expression of ileal cellular regulatory factors SEC6A1 and PDE4D in LR1 group significantly decreased(P<0.05).Compared with the AO group(P<0.05),the gene expression of the extracellular regulator MMP2 was significantly lower in the LR1 group(P<0.05);and the gene expression of the intracellular regulator SEC6A1 and cytokine TGF-β significantly decreased in the LR1 group.[Conclusion]Addition of porcine L.reuteri LR1 to the diet could modulate ECM remodeling by reducing gene expression of ECM regulators SEC6A1,PDE4D and other genes.

IntroductionMore effective and environment-friendly organic trace minerals have great potential to replace the inorganic elements in the diets of livestock. This study aimed to investigate the effects of dietary replacement of 100% inorganic trace minerals (ITMs) with 30–60% organic trace minerals (OTMs) on the performance, meat quality, antioxidant capacity, nutrient digestibility, and fecal mineral excretion and to assess whether low-dose OTMs could replace whole ITMs in growing-finishing pigs' diets.MethodsA total of 72 growing-finishing pigs (Duroc × Landrace × Yorkshire) with an initial average body weight of 74.25 ± 0.41 kg were selected and divided into four groups with six replicates per group and three pigs per replicate. The pigs were fed either a corn-soybean meal basal diet containing commercial levels of 100% ITMs or a basal diet with 30, 45, or 60% amino acid-chelated trace minerals instead of 100% ITMs, respectively. The trial ended when the pigs' weight reached ~110 kg.ResultsThe results showed that replacing 100% ITMs with 30–60% OTMs had no adverse effect on average daily gain, average daily feed intake, feed/gain, carcass traits, or meat quality (P > 0.05) but significantly increased serum transferrin and calcium contents (P < 0.05). Meanwhile, replacing 100% ITMs with OTMs tended to increase serum T-SOD activity (0.05 ≤ P < 0.1), and 30% OTMs significantly increased muscle Mn-SOD activity (P < 0.05). Moreover, replacing 100% ITMs with OTMs tended to increase the apparent digestibility of energy, dry matter, and crude protein (0.05 ≤ P < 0.1) while significantly reducing the contents of copper, zinc, and manganese in feces (P < 0.05).DiscussionIn conclusion, dietary supplementation with 30–60% OTMs has the potential to replace 100% ITMs for improving antioxidant capacity and nutrient digestibility and for reducing fecal mineral excretion without compromising the performance of growing-finishing pigs.

Proanthocyanidins（PACs）are important natural biologically active substances that are widely existing in various plants. Recent studies have shown that the addition of PACs from different sources in animal diets can regulate the diversity and composition of intestinal microbiota,and interact with the intestinal mucosal immune system through the microbiota and their metabolites to regulate the intestinal immune response. This paper reviewed the role of PACs played in shaping intestinal microbiota and their metabolites,and summarized the regulation of PACs on intestinal immune response and possible mechanisms,providing a reference for the basic research and application of PACs in improving animal intestinal health.[Chinese Journal of Animal Nutrition,2023,35（3）:1454-1467]

This experiment was conducted to evaluate effects of zine oxide (ZnO) and condensed tannins (CT), independently or in combination, on the growth performance and intestinal health of weaned piglets in enterotoxigenic Escherichia coli (ETEC-K88)-challenged environment. Randomly divided 72 weaned piglets into 4 groups. Dietary treatments included the following: basic diet group (CON), 1,500 mg/kg zinc oxide group (ZnO), 1,000 mg/kg condensed tannins group (CT), and 1,500 mg/kg zinc oxide +1,000 mg/kg condensed tannins group (ZnO + CT). Dietary ZnO supplementation decreased diarrhea rate from 0 to 14 days, 15 to 28 days, and 0 to 28 days (p < 0.05) and no significant on growth performance. The effect of CT on reducing diarrhea rate and diarrhea index was similar to the results of ZnO. Compared with the CON group, ZnO increased the ileum villus height and improved intestinal barrier function by increasing the content of mucin 2 (MUC-2) in jejunum and ileum mucosa and the mRNA expression of zonula occludens-1 (ZO-1) in jejunum (p < 0.05) and the expression of Occludin in duodenum and ileum (p < 0.05). The effects of CT on intestinal barrier function genes were similar to that of ZnO. Moreover, the mRNA expression of cystic fibrosis transmembrane conductance regulator (CFTR) in jejunum and ileum was reduced in ZnO group (p < 0.05). And CT was also capable of alleviating diarrhea by decreasing CFTR expression and promote water reabsorption by increasing AQP3 expression (p < 0.05). In addition, pigs receiving ZnO diet had higher abundance of phylum Bacteroidetes, and genera Prevotella, and lower phylum Firmicutes and genera Lactobacillus in colonic contents. These results indicated that ZnO and CT can alleviate diarrhea and improve intestinal barrier function of weaned pigs in ETEC-challenged environment. In addition, the application of ZnO combined with CT did not show synergistic effects on piglet intestinal health and overall performance. This study provides a theoretical basis for the application of ZnO in weaning piglet production practices, we also explored effects of CT on the growth performance and intestinal health of weaned piglets in ETEC-challenged environment.

本试验旨在研究饲粮添加甜叶菊废渣提取物对断奶仔猪生长性能、血常规及生化指标、抗氧化活性、脏器指数和内脏组织病理的影响,以系统评价断奶仔猪对甜叶菊废渣提取物的耐受性.试验选用平均初始体重为(6.79±0.02)kg的21日龄杜×长×大断奶仔猪108头,随机分为3组,每组6个重复,每个重复6头.对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加400、4 000 mg/kg甜叶菊废渣提取物的饲粮.试验期42 d.结果表明:与对照组相比,1)试验第1～28天及第1～42天,添加甜叶菊废渣提取物对断奶仔猪平均日增重、平均日采食量、料重比及腹泻率均无显著影响(P＞0.05);2)添加甜叶菊废渣提取物对断奶仔猪血常规指标均无显著影响(P＞0.05),添加4 000 mg/kg甜叶菊废渣提取物可显著提高血清碱性磷酸酶活性(P＜0.05);3)添加400 mg/kg甜叶菊废渣提取物可显著降低血清丙二醛(MDA)含量并显著提高总超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性(P＜0.05),且添加4 000 mg/kg甜叶菊废渣提取物显著降低血清MDA含量并显著提高T-SOD活性(P＜0.05);4)添加甜叶菊废渣提取物对心脏、肝脏、脾脏、肺脏、肾脏、胰腺等脏器指数均无显著影响(P＞0.05),且组织病理学观测未发现心脏、肝脏、脾脏、肺脏、肾脏等组织有明显病变.综上所述,饲粮中添加甜叶菊废渣提取物可改善断奶仔猪抗氧化性能,对生长性能、血常规指标、脏器指数等均无不良影响,且组织病理学观测未发现明显病理变化.因此,断奶仔猪可耐受饲粮中4 000 mg/kg甜叶菊废渣提取物.

本试验旨在研究低氮磷玉米-豆粕型饲粮对育肥后期猪生长性能、粪污排放及肉品质的影响.选取60头体重为(131.68±0.62)kg的杜×长×大育肥猪,随机分为3个组,分别为对照组、试验Ⅰ组和试验Ⅱ组,每组5个重复,每个重复4头猪.对照组的饲粮为玉米-豆粕型基础饲粮,不添加植酸酶;试验Ⅰ组的饲粮在对照组饲粮基础上降低磷水平(0.35％vs 0.24％)并添加植酸酶(1 000 IU/kg),且停用微量元素;试验Ⅱ组的饲粮在试验Ⅰ组饲粮的基础上进一步降低饲粮氮水平(11.09％vs 9.87％).试验期28 d.结果表明:与对照组比较,试验Ⅰ组和试验Ⅱ组的生长性能、血清钙和磷含量、粗蛋白质表观消化率、肉品质及抗氧化活性等均无显著差异(P＞0.05);但是干物质表观消化率分别提高了 2.45％和3.00％(P＜0.05),粗灰分表观消化率分别提高了 69.10％和78.49％(P＜0.05);同时粪便粗灰分含量分别下降了 12.44％和17.83％(P＜0.01),粪便磷含量分别下降了 17.31％和21.92％(P＜0.01),粪便铜含量分别下降了 54.81％和60.25％(P＜0.01),粪便锌含量分别下降了 71.10％和75.65％(P＜0.01).并且试验Ⅰ组和试验Ⅱ组之间的生长性能、养分表观消化率、粪污排放、肉品质及抗氧化活性等均无显著差异(P＞0.05).综上所述,育肥后期饲喂停用微量元素的低氮磷玉米-豆粕型饲粮,可以显著提高养分表观消化率,并有效减少粪便磷、铜及锌等的排放,且对猪生长性能和肉品质无负面影响.