Yuyong He

Newborn piglets in intensive pig farms are often prone to pulmonary diseases due to underdeveloped fetal lung neural systems, and ATRA is often regarded as an important morphogen that displays pleiotropic functions during embryonic development. However, information about the effect of maternal administration with ATRA on the peripheral neural system of fetal lungs is still scare. Fifteen pregnant sows were assigned to the ATRA0 (0 mg/kg diet), ATRA4, ATRA8, ATRA16 and ATRA32 treatment groups and offered their own feed from d12 to d95 after artificial insemination; then two neonatal pigs with birth weights similar to the average birth weight were taken out from each litter for the collection of lung samples, and samples were subjected to immunofluorescence staining, RNA-seq and RT-qPCR assays. Results indicated that compared to newborn piglets from the ATRA0 treatment group, newborn piglets from the ATRA4 treatment group had higher percentages of GFAP-positive astrocyte cells (p < 0.05) and GFAP-TUBB3 colocalization (p < 0.05) in the lungs. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that differential expressed genes are mainly enriched in the pathways of neuroactive ligand–receptor interaction, GABAergic synapses and cell adhesion molecules. Addition of ATRA at 4 mg/kg to the diet of pregnant sows can enhance the healthy development of the pulmonary nervous systems of fetal pigs.

(1) Background: How to reduce respiratory diseases in animals is a matter of great concern, and this study aimed to investigate the effect of maternal administration with all-trans retinoic acid (ATRA) on the lung health of neonatal pigs. (2) Methods: Fifteen sows were randomly allotted to one of five ATRA groups (0, 4, 8, 16, and 32 mg/kg diet), respectively; on average, from days 12 to 95 after insemination, lung samples of neonatal pigs were harvested for HE staining, 16S DNA sequencing, and transcriptomic analysis. (3) Results: Compared to neonatal pigs from the ATRA0 group, neonatal pigs from the ATRA4 group had an increased (p > 0.05) alveolar number and the thinner (p < 0.05) alveolar septum, higher (p < 0.05) abundance of Akkermansia and unidentified_Mitochondria, and a lower (p < 0.05) abundance of Acinetobacter, Cutibacterium, Stenotrophomonas, Enterobacter, Saccharomonospora, and Alistipes in the lungs. Maternal supplementation of ATRA at 4 mg/kg diet had the benefits of reducing pathogen virulence and drug resistance, but it poses the risk of increasing the resistance to β-lactam antibiotics. In addition, it reduced (p < 0.05) the virulence, drug resistance, and stress tolerant capacity of potential pathogens (Proteobacteria, Acinetobacter, Cupriavidus, and Pseudomonas), enriched the highest number of genes in neuroactive ligand–receptor interaction pathway, and decreased gene expression of CCL11 and IL9 in the asthma pathway. (4) Conclusions: Maternal supplementation of ATRA at 4 mg/kg diet can strengthen the lung health of neonatal pigs by improving alveolar development, decreasing the number and virulence of pathogens, and down-regulating the expression of asthma-related genes.

The influence of supplementing glycerol, vitamin C and niacinamide on the liver of growing-finishing pigs has not yet been examined. This study investigated the effect of 10% glycerol, 0.06% vitamin C and 0.05% niacinamide supplementation at single or combination on liver of growing-finishing pigs. Compared with pigs supplemented with 0% glycerol, 0% vitamin C and 0% niacinamide, pigs supplemented only with 10% glycerol had higher (p < 0.05) TNF-α concentration, partially hepatic steatosis, higher (p < 0.05) relative abundances of Escherichia_shigella, Prevotellaceae_UCG_003, Lachnospiraceae_XPB1014_group, Coprococcus, Lactococcus and Megamonas, lower (p < 0.05) solute carrier family 7 member 11 (SLC7A11) expression in liver tissue. However, pigs offered the diet with a mixture of 0.06% vitamin C and 0.05% niacinamide had higher (p < 0.05) relative abundance of Faecalibaculum and expression of SLC7A11, lower (p < 0.05) relative abundances of Staphylococcus and Clostridium_sensu_stricto_1 in liver tissue. Supplementation of 10% glycerol, 0.06% vitamin C and 0.05% niacinamide simultaneously to pigs increased (p < 0.05) the ferrous ion level, the relative abundances of Escherichia_Shigella, Lactococcus and Desulfobacterota, the expressions of gene Cryptochrome-1(CRY1) and SLC7A11, but decreased (p < 0.05) the expressions of gene C-reactive protein (CRP) and galactokinase 1 (GALK1) in liver tissue. Supplementation with 0.06% vitamin C and 0.05% niacinamide can alleviate the damage in liver of pigs fed a diet containing 10% glycerol.

Background: The use of in-feed antibiotics was banned in numerous countries within the animal production industry as a result of the emergence of antibiotic-resistant bacteria and the presence of residual antibiotics. Bacteriophages, which are viruses that infect host bacterial cells, are considered the natural predators of bacteria. Over the past two decades, bacteriophages have garnered increasing attention for their potential in controlling pathogenic bacteria in weaned piglets. Aims: The aim of this overview was to update the progress of bacteriophage application in weaned piglets. Methods: For the section on bacteriophage application in weaned piglets, a systematic search was performed to identify relevant articles published before June 2025 in databases such as Web of Science. Results: In this review, we provide a brief overview of bacteriophages, followed by a summary of the isolation of specific bacteriophages in weaned piglets. In addition, we have summarized the application progress of bacteriophages in weaned piglets, including the effects of oral administration or dietary supplementation with bacteriophages on growth performance, diarrhea characteristics, intestinal morphology, intestinal pH, nutrient digestibility, inflammatory response, intestinal barrier function, and intestinal microecology. Conclusions: This updated overview novelly highlights the potential of bacteriophages as anti-pathogenic agents in mitigating infections caused by pathogenic bacteria in weaned piglets. This review could provide a scientific basis for controlling pathogenic bacteria infections in weaned piglets in the post-antibiotic era.

The aim of this study was to investigate the effects on the tibia, liver, and gut, and on performance, when supplementing nursery pigs with different levels of rare earth–chitosan chelate (RECC). A total of 80 piglets, weaned at 7.67 ± 0.09 kg, were randomly assigned to groups RECC0 (RECC, 0 mg/kg diet), RECC200 (RECC, 200 mg/kg diet), RECC400 (RECC, 400 mg/kg diet), and RECC600 (RECC, 600 mg/kg diet), with four replicates in each group and five pigs per replicate during a 28 d experiment. Samples of the left hind tibia, serum, and feces were collected for analysis. The results indicated that, compared to pigs from group RECC0, pigs from group RECC200 presented with the following: a longer trabecular perimeter (p < 0.05), a larger trabecular area (p < 0.01), a higher trabecular number (p < 0.05), a smaller degree of trabecular separation (p < 0.01), and a lower number of osteoclasts (p < 0.01) in the tibia; higher abundances of beneficial fecal bacteria such as g_Prevotellaceae_NK3B31_group, g_UCG_005, g_Rikenellaceae_RC9_gut_group, g_Acetitomaculum, g_Glutamicibacter, g_Frisingicoccus, and g_Alistipes; higher (p < 0.01) serum levels of IgM, IgA, IgG, and IL-10; a lower (p < 0.01) serum concentration of TNF-α; a higher (p < 0.05) average daily gain and feed conversion ratio; and a lower (p < 0.01) incidence of diarrhea. The dietary addition of RECC contributes to improvements in tibia quality, gut health, and performance in nursery pigs.

This study aimed to investigate the effects of dietary bacteriophage administration on diarrhea and intestinal impairment induced by enterotoxigenic Escherichia coli (ETEC) in a newly weaned mouse model. Forty-four newly weaned C57BL/6 mice were divided into four treatment groups, where they were provided either the control diet or the bacteriophage-supplemented diet, with or without ETEC infection. The results show that the bacteriophage administration resulted in increased body weight, decreased diarrhea score, and improved jejunal histopathology in ETEC-infected mice. The bacteriophage administration enhanced the intestinal barrier function of the ETEC-infected mice, as indicated by the reduced serum DAO level and the increased expression of Claudin-1, Occludin, and ZO-1 at both the mRNA and protein levels in the jejunum. Also, the bacteriophage administration resulted in a decrease in serum TNF-α and IL-1β levels, a down-regulation of TNF-α and IL-6 mRNA levels in the jejunum, and the inhibition of jejunal TLR-4/NF-κB pathway activation induced by ETEC infection. Moreover, the bacteriophage administration increased the levels of acetic acid, propionic acid, butyric acid, and total short-chain fatty acids in the caecum content. The bacteriophage administration increased the Shannon index, increased the abundance of Bacteroidota and Muribaculaceae, and decreased the abundance of Verrucomicrobiota and Akkermansiaceae in the colon contents of the ETEC-infected mice. Spearman’s correlation analysis indicates that the protective effects of bacteriophage on ETEC-induced intestinal impairment, inflammation, and intestinal barrier function are associated with regulating the abundance of Bacteroidota and Muribaculaceae in the colon contents of mice. Collectively, bacteriophage administration alleviates ETEC-induced diarrhea and intestinal impairment through regulating intestinal inflammation and gut microbiota in newly weaned mice.

The addition of glycerin, vitamin C, and niacinamide to pig diets increased the redness of longissimus dorsi; however, it remains unclear how these supplements affect gut microbiota and metabolites. A total of 84 piglets (20.35 ± 2.14 kg) were randomly allotted to groups A (control), B (glycerin-supplemented), C (vitamin C and niacinamide-supplemented), and D (glycerin, vitamin C and niacinamide-supplemented) during a feeding experiment. Metagenomic and metabolomic technologies were used to analyze the fecal compositions of bile acids, metabolites, and microbiota. The results showed that compared to pigs in group A, pigs in group D had lower virulence factor expressions of lipopolysaccharide (p < 0.05), fatty acid resistance system (p < 0.05), and capsule (p < 0.01); higher fecal levels of ferric ion (p < 0.05), allolithocholic acid (p < 0.01), deoxycholic acid (p < 0.05), tauroursodeoxycholic acid dihydrate (p < 0.01), glycodeoxycholic acid (p < 0.05), L-proline (p < 0.01) and calcitriol (p < 0.01); and higher (p < 0.05) abundances of iron-acquiring microbiota (Methanobrevibacter, Clostridium, Clostridiaceae, Clostridium_sp_CAG_1000, Faecalibacterium_sp_CAG_74_58_120, Eubacteriales_Family_XIII_Incertae_Sedis, Alistipes_sp_CAG_435, Alistipes_sp_CAG_514 and Methanobrevibacter_sp_YE315). Supplementation with glycerin, vitamin C, and niacinamide to pigs significantly promoted the growth of iron-acquiring microbiota in feces, reduced the expression of some virulence factor genes of fecal pathogens, and increased the fecal levels of ferric ion, L-proline, and some secondary bile acids. The administration of glycerol, vitamin C, and niacinamide to pigs may serve as an effective measure for muscle redness improvement by altering the compositions of fecal microbiota and metabolites.

The objective of this study was to determine the influence of supplementing the diet of growing–finishing pigs with glycerin and/or a mixture of vitamin C and niacinamide on carcass traits and pork quality. Eighty-four weaned piglets with an initial average body weight of 20.35 ± 2.14 kg were assigned, at random, to four groups for a 103-day feeding experiment: control; glycerin-supplemented group; vitamin C and niacinamide-supplemented group; and glycerin, vitamin C and niacinamide-supplemented group. At the end of the experiment, three pigs/group were randomly selected and slaughtered, and samples were collected for analysis. The results indicated that supplementing crossbred pigs with glycerin, vitamin C and niacinamide simultaneously increased the redness (a*) value (p < 0.05), glycerol content (p < 0.01) and myristoleic acid content (p < 0.01) in the longissimus dorsi and tended to increase the level of flavor amino acids, linoleic acid, linolenic acid and erucic acid, as well as the percentage and density of type I myofibers in the longissimus dorsi and the semimembranosus muscle. Glycerin had an influence (p < 0.01) on the erucic acid content in the longissimus dorsi and the semimembranosus muscle, and vitamin C and niacinamide had an interaction effect (p < 0.05) on the redness (a*) value of the longissimus dorsi. Glycerin, vitamin C and niacinamide supplementation in the diet of crossbred pigs improved the color, flavor and nutritional value of pork, which contributed to an increased intent to purchase this product.

Neonatal Hoxa1^−/− piglets were characterized by dyspnea owing to the Hoxa1 mutation, and maternal administration with ATRA alleviated the dyspnea of neonatal Hoxa1^−/− piglets. The purpose of this experiment was to explore how maternal ATRA administration rescued the abnormal fetal lungs of Hoxa1^−/− piglets. Samples of the lungs were collected from neonatal Hoxa1^−/− and non-Hoxa1^−/− piglets delivered by sows in the control group, and from neonatal Hoxa1^−/− piglets born by sows administered with ATRA at 4 mg/kg body weight on dpc 12, 13, or 14, respectively. These were used for the analysis of ELISA, histological morphology, immunofluorescence staining, immunohistochemistry staining, and quantitative real-time PCR. The results indicate that the Hoxa1 mutation had adverse impacts on the development of the alveoli and pulmonary microvessels of Hoxa1^−/− piglets. Maternal administration with ATRA at 4 mg/kg body weight on dpc 14 rescued the abnormal lung development of Hoxa1^−/− piglets by increasing the IFN-γ concentration (p < 0.05), airspace area (p < 0.01) and pulmonary microvessel density (p < 0.01); increasing the expression of VEGFD (p < 0.01), PDGFD (p < 0.01), KDR (p < 0.01), ID1 (p < 0.01), and NEDD4 (p < 0.01); and decreasing the septal wall thickness (p < 0.01) and the expression of SFTPC (p < 0.01) and FOXO3 (p < 0.01). Maternal administration with ATRA plays a vital role in rescuing the abnormal development of lung of Hoxa1^−/− fetal piglets.

Different untargeted metabolomics approaches were used to identify the differential metabolites between milk samples collected from two groups. Sows were supplemented with fermented compound Chinese medicine feed additive at levels of 0 g/d/sow (control group, n = 10) and 50 g/d/sow (experimental group, n = 10), respectively, from d 104 of gestation to d 25 of lactation, samples of colostrum and mature milk were collected. Data indicated that supplementing fermented compound Chinese medicine feed additive to sows significantly increased the concentrations of quercetin, pinocembrin, chlorogenic acid, methyl succinic acid, L-tryptophan, adenosine, guanine, arteannuin, ferulic acid, echimidine N-oxide, pogostone and kynurenine in the colostrum and inosine, guanosine, benzene-1,2,4-triol, hypoxanthine, adenine, trehalose 6-phosphate in mature milk, respectively. Seven pathways (flavone and flavanol biosynthesis, galactose metabolism, phenylpropanoid biosynthesis, stilbenoid and gingerol biosynthesis, flavonoid biosynthesis, ABC transporters and purine metabolism) in colostrum and two pathways (sucrose metabolism and retrograde endocannabinoid signaling) in mature milk were significantly enriched in the experimental group compared to control group, respectively. The supplementation of fermented compound Chinese medicine feed additive to sows increased the level of antibacterial and anti-inflammatory ingredients in milk and the findings of this study hint that supplementation with fermented compound Chinese medicine feed additive in sows is beneficial for the improvement of milk quality.