Dietary replacement of inorganic trace minerals with lower levels of organic trace minerals leads to enhanced antioxidant capacity, nutrient digestibility, and reduced fecal mineral excretion in growing-finishing pigs.

Introduction: More 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. Methods: A 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. Results: The 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). Discussion: In 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.

Effects of zinc oxide and condensed tannins on the growth performance and intestinal health of weaned piglets in ETEC-challenged environment.

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.

Dietary supplementation with potassium-magnesium sulfate modulates the antioxidant capacity, immunity, and gut microbiota in weaned piglets.

The purpose of this study was to evaluate the effects of different levels of potassium magnesium sulfateon (PMS) on growth performance, diarrhea rate, intestinal morphology, antioxidant capacity, intestinal immunity, and gut microbiota in weaned piglets. A total of 216 weaned piglets were randomly divided into six dietary groups: the basal diet with 0% (CON), 0.15, 0.3, 0.45, 0.6, and 0.75% PMS. The results showed that the ADFI of 29-42 days and 1-42 days was linearly and quadratically increased by the PMS supplementation (P < 0.05), and significantly reduced the diarrhea rate in weaned piglets (P < 0.05). Moreover, dietary supplementation with PMS significantly reduced the serum adrenaline and noradrenaline levels in weaned piglets (P < 0.05). Furthermore, 0.3% PMS significantly increased the activity of glutathione peroxidase (GSH-Px) in the jejunum (P < 0.05) and tended to increase the activity of superoxide dismutase (SOD) in the jejunal mucosa of piglets (P < 0.1). Additionally, dietary supplementation with PMS significantly reduced the interleukin-1ß (IL-1ß) level in the jejunal mucosa (P < 0.05), and 0.3% PMS increased the serum IgM content in piglets (P < 0.05). Furthermore, the analysis of colonic microbiota by 16S RNA sequencing showed that the addition of PMS increased the Shannon index (P < 0.05) and Observed Species index (P < 0.05). Based on linear discriminant analysis effect size (LEfSe) and T-test analysis, the addition of PMS increased the relative abundance of Ruminococcaceae and Peptostreptococcaceae in the colonic digesta (P < 0.05). Spearman analysis showed that there was a positive correlation between intestinal GSH-Px activity and the relative abundance of Peptostreptococcaceae. These results showed that dietary supplementation with PMS could improve growth performance, alleviate diarrhea incidence, and modulate the antioxidant capacity and intestinal immunity in weaned piglets, which was partially related to the significant changes in colonic microbiota composition.

Dietary Hermetia illucens Larvae Meal Improves Growth Performance and Intestinal Barrier Function of Weaned Pigs Under the Environment of Enterotoxigenic Escherichia coli K88.

The aim of this study was to evaluate the effect of Hermetia illucens larvae meal (HI) on the growth performance and intestinal barrier function of weaned pigs. To achieve this, 72 weaned pigs [28-day-old, 8.44 ± 0.04 kg body weight (BW)] were randomly assigned to three dietary treatments: basal diet (negative control, NC), zinc oxide-supplemented diet (positive control, PC), and HI-supplemented diet [100% replacement of fishmeal (FM), HI], for 28 days in the presence of enterotoxigenic Escherichia coli (ETEC). The results showed that HI and PC increased (p < 0.05) the average daily gain (ADG) and average daily feed intake (ADFI) of weaned pigs from day 1 to 14, and decreased diarrhea incidence from day 1 to 28. Additionally, HI increased (p < 0.05) claudin-1, occludin, mucin-1 (MUC-1), and MUC-2 expression, goblet cell number, and secretory immunoglobulin A (sIgA) concentration in the intestine of weaned pigs. Compared with NC, HI downregulated (p < 0.05) interleukin-1ß (IL-1ß) and IL-8 expression, and upregulated IL-10, transforming growth factor-ß (TGF-ß), antimicrobial peptide [porcine ß defensin 1 (pBD1), pBD2, protegrin 1-5 (PG1-5)] expression in the jejunum or ileum. Moreover, HI decreased (p < 0.05) toll-like receptor 2 (TLR2), phosphorylated nuclear factor-κB (p-NF-κB), and phosphorylated mitogen-activated protein kinase (p-MAPK) expression, and increased sirtuin 1 (SIRT1) expression in the ileum. Additionally, HI increased histone deacetylase 3 (HDAC3) expression and acetylation of histone 3 lysine 27 (acH3k27) in the ileum. Furthermore, HI positively influenced the intestinal microbiota composition and diversity of weaned pigs and increased (p < 0.05) butyrate and valerate concentrations. Overall, dietary HI improved growth performance and intestinal barrier function, as well as regulated histone acetylation and TLR2-NF-κB/MAPK signaling pathways in weaned pigs.

Arginine accelerates intestinal health through cytokines and intestinal microbiota.

Arginine supplementation improves intestinal damage and intestinal immunity, but the underlying mechanism of the effects of arginine supplementation on intestinal SIgA secretion is largely unknown. Therefore, this study was conducted to investigate the underlying pathway on the effects of arginine supplementation in secretory IgA (SIgA) production in mice. The results showed that 0.4% arginine supplementation promoted (P < 0.05) SIgA production in intestinal lumina and IgA+ plasma cell numbers in the ileum of mouse. Arginine supplementation significantly increased (P < 0.05) cytokines expression in mouse ileal associated with T cell-dependent and T cell-independent pathways of SIgA induction, including IL-5, IL-6, IL-13, transforming growth factor (TGF-)ß2, TGF-ß3, TGF-ßR2, a proliferation-inducing ligand (APRIL), B cell-activating factor (BAFF), vasoactive intestinal peptide (VIP) receptor, and retinal dehydrogenases. Further study showed that 0.4% arginine supplementation markly decreased (P < 0.05) bacterial loads in mouse mesenteric lymph nodes and increased bacterial invasion into the mouse ileal wall, while supplementation of antibiotic abrogated the influence of arginine supplementation on SIgA secretion. Therefore, these data suggest that arginine supplementation might promote SIgA secretion through cytokines and intestinal microbiota might play an important role in SIgA secretion by arginine supplementation in the mouse intestine.