BACKGROUND This study was conducted to evaluate the health benefits to weaning pigs, raised under low sanitary conditions, of dietary supplementation with a multi‐strain yeast fraction product (Cyberlindnera jadinii and Saccharomyces cerevisiae). In total, 160 weaning pigs (7.21 ± 1.05 kg) were randomly allotted to two dietary treatments in a 6‐week feeding trial. The dietary treatments included a corn‐soybean meal‐based basal diet (CON) and CON + 2 g kg−1 multi‐strain yeast fraction product (MsYF) during weeks 1–2 and 0.4 g kg−1 MsYF during weeks 3–6. RESULTS The MsYF supplementation increased (P < 0.05) body weight (BW) at day 42 and average daily gain (ADG) during days 1–14 and days 1–42 (P < 0.05) compared to CON. The total tract digestibility of dry matter (DM), fecal Lactobacillus counts, and serum immunoglobulin G (IgG) concentration at day 42 were higher (P < 0.05) in pigs fed a MsYF supplemented diet. The concentration of serum haptoglobin in pigs receiving a MsYF‐supplemented diet was higher (P < 0.05) at days 7, 14, and 42 than those receiving CON. The mRNA expression for INF‐γ and TNF‐α genes were lower (P < 0.05) at days 14 and 7 respectively and the expression of IL‐6 and TLR‐2 genes was lower (P < 0.01) at days 7 and 14 in pigs fed an MsFY supplemented diet than those fed CON. CONCLUSION Supplementation with a multi‐strain yeast fraction product had a positive effect on ADG during the early post‐weaning period and led to better health in weaning pigs. © 2019 Society of Chemical Industry

The objective of the trial was to evaluate the effect of a novel multi-strains yeast fractions product (MsYF) on performance, digestibility, and gene expression of several cytokines in weanling piglets reared under low sanitary environment (uncleaned). In total, 160 piglets weaned at 24 days (7.21 ± 1.05kg) were distributed in 2 treatments according to body weight and sex: control (CON), and MsYF (CON+2kg/ton of yeast product in the first 14 days post weaning; CON+400g/ton of product between days 14 and 42). Individual body weight (BW) and feed intake (FI) were measured on days 1, 14 and 42. Apparent total tract digestibility (ATTD) of dry matter (DM) and crude protein (CP) was estimated at the end of the experiment using chromium oxide as indigestible marker. On days 7, 14 and 42, 6 piglets per treatment were slaughtered and sampled from the mid-jejunum to measure cytokines mRNA gene expression: tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), toll-like receptor 2 (TLR2), interleukin 1 receptor 1 (IL-1-R1), interleukin 10 (IL-10), interleukin 1β (IL-1β), interleukin 12 (IL-12), interferon gamma (INF- γ), and (GATA3). Data were analyzed by ANOVA using the T-test procedure of SAS (SAS Inst. Inc., Cary, US) with treatment as main effect. Piglets fed MsYF had greater (P < 0.05) final BW and greater (P < 0.01) ADG compared to piglets fed CON. Piglets fed MsYF tended to have greater (P < 0.1) ATTD of DM than piglets fed CON. Supplementation of MsYF down-regulated the expressions of TNF-α, IL-6, and TLR2 on days 7 and 14 (P < 0.01 and P < 0.1 for TNF-α, P < 0.01 and P < 0.001 for IL-6, and P < 0.0001 and P < 0.001 for TLR2) while a reduced (P < 0.01) INF-γ expression occurred in piglets fed MsYF at day 14. In conclusion, supplementation with yeast improved performance, DM digestibility, and may modulate intestinal mucosa inflammation of weanling piglets under low sanitary environment.