Hydrolysed yeast from Kluyveromyces fragilis improves plasma antioxidant efficiency and immunoglobulin concentration, and faecal microbiota of weaned piglets

The aim of this study was to evaluate the effect of hydrolysed yeast from Kluyveromyces fragilis (HK) on growth performance, diarrhoea incidence, plasma antioxidant efficiency and immune status, and faecal microbiota of weaned piglets. A total of 100 weaned piglets with BW (7.03 ± 0.14 kg) and age (25 ± 1 days) were randomly allotted to 4 groups with 5 replicates in a 21-day experiment. Piglets were fed with basal diet (NC), NC + 2 g/kg zinc oxide (PC), NC + 7.5 g/kg HK (HK1), or NC + 10 g/kg HK (HK2). Blood and faecal samples were collected on day 21. Significant differences were pointed out in the PC and HK2 piglets compared to the NC group as to the diarrhoea incidence from day 0 to 21 (p < 0.001; p = 0.032), the activity of plasma superoxide dismutase (p = 0.019; p = 0.003) and the concentration of plasma malondialdehyde (p = 0.042; p = 0.010). Moreover, significant differences were pointed out in the HK2 piglets compared to the NC group as to the content of plasma immunoglobulin A (p = 0.005), the Ace index and Chao1 index (p = 0.023; p = 0.018,) and the relative abundance of Campylobacterota and Escherichia-Shigella (p = 0.023; p = 0.032). In conclusion, dietary HK at 10 g/kg alleviated diarrhoea incidence of piglets that might be attribute to the improved plasma antioxidant efficiency and immune status and the regulated faecal microbial community, and could be alternative to the high dose ZnO.