Yeast and its derivatives, including yeast extract and yeast cell wall, are well established as safe and environmentally sustainable feed additives that significantly improve animal production performance and health. Their incorporation into swine production serves as an innovative nutritional strategy aimed at improving growth performance, bolstering health status, and enhancing immune function in pigs. As a versatile microorganism, yeast generates a variety of bioactive compounds through fermentation, such as amino acids, vitamins, enzymes, and growth factors, which collectively contribute to improved growth and overall health in pigs. This review consolidates current research on the utilization of yeast and yeast derivatives in swine production, highlighting their biological functions and practical implications within the industry.

The aim of this experiment is to evaluate the effects of adding porous zinc oxide, plant polyphenols, and their combination to diets without antibiotics and high-dose zinc oxide on the growth performance, diarrhea incidence, intestinal morphology, and microbial diversity of weaned piglets. A total of 150 Duroc × Landrace × Large White weaned piglets were allocated to one of five diets in a randomized complete block design with six replicates and five piglets per replicate. The experimental period was 42 d, divided into two feeding stages: pre-starter (0–14 d) and starter (14–42 d). In the pre-starter stage, the negative control group (NC) was fed a basal diet, the positive control group (PC) was fed a basal diet with 2000 mg/kg of zinc oxide, the porous zinc oxide group (PZ) was fed a basal diet with 500 mg/kg of porous zinc oxide, the plant polyphenol group (PP) was fed a basal diet with 1500 mg/kg of plant polyphenols, and the combination group (PZ + PP) was fed a basal diet with 500 mg/kg of porous zinc oxide and 1500 mg/kg of plant polyphenols. In the starter stage, the NC, PC, and PZ groups were fed a basal diet, while the PP and PZ + PP groups were fed a basal diet with 1000 mg/kg of plant polyphenols. The results showed that, (1) compared with the PZ group, adding plant polyphenols to the diet showed a trend of increasing the ADFI of weaned piglets from 14 to 28 d (p = 0.099). From days 28 to 42 and days 0 to 42, porous zinc oxide and the combination of porous zinc oxide and plant polyphenols added to the control diet improved the FCR to the level observed in pigs fed the PC diet. (2) Dietary PZ + PP tended to increase the jejunal villus height (VH) of weaned piglets (p = 0.055), and significantly increased the villus-height-to-crypt-depth ratio compared to the NC group (p < 0.05). (3) Compared with the NC group, PZ supplementation decreased the relative abundance of Firmicutes and increased the relative abundance of Bacteroidetes, and the relative abundance of Lactobacillus in the PZ and PZ + PP groups were both increased. In conclusion, porous zinc oxide and plant polyphenols may have synergistic effects in modulating intestinal health in weaned piglets and be a potential alternative to high-dose zinc oxide.

This study was conducted to investigate the effects of dietary supplementation with stimbiotics (STB) on growth performance, diarrhoea incidence, plasma antioxidant capacity, immunoglobulin concentration and hormone levels, and faecal microorganisms in weaned piglets. Compared with the control (CT) group, the addition of STB improved the body weight (BW) of piglets on days 28 and 42 (p < 0.05) and increased daily weight gain and daily feed intake from days 14–28 and throughout the trial period (p < 0.05). Correspondingly, the plasma insulin-like growth factor 1 (IGF-1) level on day 42 was significantly improved by STB (p < 0.05). VistaPros (VP) group levels of immunoglobulin (Ig) A and G were significantly higher on days 14 and 42 (p < 0.05) than the CT group levels. In addition, the activity of plasma catalase tended to be increased on day 14 (p = 0.053) in the VP group, as for superoxide dismutase, glutathione peroxidase, and malondialdehyde, STB did not significantly affect their levels (p > 0.05). Moreover, dietary STB increased the relative abundance of beneficial bacteria, including norank_f_Muribaculaceae, Rikenellaceae_RC9_gut_group, Parabacteroides, and unclassified_f__Oscillospiraceae. In summary, STB improved the immunity and IGF-1 levels in the plasma of weaned piglets and consequently promoted the growth performance of weaned piglets.

Growth stagnation or weight loss is prevalent in weaned piglets, with post-weaning diarrhea severely compromising intestinal health, underscoring the criticality of intestinal structural integrity for preventing digestive disorders. Tight junction proteins (TJPs), core components of intestinal intercellular junctions, play indispensable roles in maintaining barrier function, nutrient absorption, and intestinal homeostasis by regulating paracellular permeability and mediating immune defense-related signaling pathways. Dysregulated TJP expression disrupts these processes and impairs piglet growth performance. Despite recent progress in characterizing TJP-mediated regulation of intestinal health in weaned piglets, key knowledge gaps remain regarding the specific regulatory mechanisms by which distinct TJP subtypes modulate intestinal microbiota–immune crosstalk. Future research should prioritize elucidating the effects of nutritional interventions on TJP expression and intestinal health, as well as the molecular mechanisms underlying TJP involvement in intestinal diseases. These efforts will provide theoretical support for developing novel feed additives and nutritional strategies to improve weaned piglet health.

Recent studies have highlighted the critical roles of the microbiota in faeces, vagina and colostrum in reproductive success and piglet development. Understanding the structural and functional dynamics of these microbial communities is essential for optimizing the health and productivity of high-yielding (HY) sows. This study aimed to characterize the structural and functional features of these microbial communities in HY sows (litter size>10 piglets) vs. low-yielding (LY) sows (≤10 piglets) and to explore their associations with sow performance and piglet health. Fifteen Yorkshire sows from each group were selected, and fresh faecal, vaginal mucus and colostrum samples were collected post-parturition. Microbial composition was analysed using 16S rRNA gene amplicon sequencing, and functional potential was predicted via PICRUSt2. Results showed that HY sows exhibited higher alpha diversity in vaginal and colostrum microbiota and greater community stability (higher neutral community model R ² values) compared to LY sows. In faeces, HY sows were enriched with Terrisporobacter and Romboutsia , while depleted in Ruminococcus _ torques _group. In the vagina, Campylobacter and Peptoniphilus were increased, whereas Eubacterium _ nodatum _group decreased. In colostrum, Lactobacillus , Bifidobacterium and Romboutsia were enriched, with reduced Peptostreptococcus , indicating a more beneficial profile for neonatal health. Functional predictions revealed distinct metabolic profiles: HY faecal microbiota upregulated cysteine/methionine metabolism and porphyrin and chlorophyll metabolism; vaginal microbiota enhanced oxidative phosphorylation and thiamine metabolism; colostrum microbiota showed enrichment in monobactam and novobiocin biosynthesis, which is associated with antimicrobial activity and stress response. These findings demonstrate that HY sows harbour a more stable and functionally advantageous microbiome across multiple biological niches, which may contribute to superior reproductive performance and improved offspring health. The results provide a foundation for developing microbiome-targeted strategies to enhance productivity and welfare in commercial pig production.

This study assessed the effect of dietary supplementation with Kluyveromyces lactis (K. lactis) hydrolysate (HKL) on growth performance, apparent nutrient digestibility, systemic immune–antioxidant status, and fecal microbiota in weaned piglets. A total of fifty-four piglets, with an initial body weight of 6.07 ± 0.086 kg and age of 25 ± 1 days, were randomly assigned to three dietary treatments over 28 days (6 replicates per treatment; 3 piglets per replicate): a control diet (CON), CON supplemented with 5 g/kg HKL (HKL1), or CON supplemented with 10 g/kg HKL (HKL2). Throughout the trial, growth performance was monitored, apparent total tract digestibility of nutrients was determined, serum samples were collected for immune and antioxidant assessments, and fecal samples were gathered for microbiota analysis. The results indicated that compared to the CON group, both HKL1 and HKL2 groups exhibited improved growth performance, as evidenced by increased average daily feed intake (ADFI) from day 0 to 28 (p < 0.05). Furthermore, HKL2 significantly enhanced average daily gain (ADG) from day 0 to 14 and reduced the feed-to-gain ratio (F: G) during the same period (p < 0.05). Diarrhea incidence was markedly decreased by HKL supplementation at both day 1–14 and day 15–28 (p < 0.001). HKL supplementation increased the apparent digestibility of dry matter, ash, calcium, and phosphorus (p < 0.05). On day 14, serum total protein and immunoglobulin A (IgA) levels were elevated, while malondialdehyde (MDA) levels were reduced in HKL-supplemented piglets (p < 0.05). By day 28, serum immunoglobulin G (IgG) concentrations, as well as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, were increased, while interleukin-6 (IL-6) levels were decreased in HKL-supplemented piglets (p < 0.05), suggesting HKL possesses immunomodulatory and antioxidant regulatory capacities. HKL also enriched several health-associated commensal bacteria, including [Eubacterium]_xylanophilum_group, unclassified_f_Peptostreptococcaceae, Candidatus Saccharimonas, Erysipelotrichaceae_UCG-003, and Negativibacillus, suggesting a microbiota-modulatory effect in weaned piglets. These results indicate that dietary supplementation with HKL could improve growth performance and nutrient utilization, reduce post-weaning diarrhea, and promote a more favorable immune–antioxidant status and microbial profile in weaned piglets, with the 10 g/kg dosage demonstrating greater overall efficacy. These findings provide a theoretical basis for the development of novel K. lactis products and the application of K. lactis hydrolysate in weaned piglets.