Effects of extruded corn distillers dried grains with solubles on growth performance, nutrient digestibility, gut health, and microbiota diversity in weaned piglets

This study was conducted to investigate the effects of extruded distillers dried grains with solubles (DDGS) on growth performance, nutrient digestibility, gut health, and gut microbiota in weaned piglets. A total of 144 piglets (Duroc × Landrace × Yorkshire, initial body weight (BW) 6.60 ± 0.35 kg) were randomly assigned to 3 treatments based on BW. The control group was fed a basal diet, while the experimental groups were fed diets supplemented with 8% and 16% extruded corn DDGS for 28 d. The results showed that feeding diets containing extruded corn DDGS had no significant impact on piglet growth performance (P > 0.05). There were no significant differences in the apparent total-tract digestibility (ATTD) of gross energy, day matter, organic matter, and crude protein between the 8% extruded corn DDGS group and the control group (P > 0.05). However, 16% DDGS supplementation reduced the digestibility of these nutrients (P < 0.05). Both the 8% and 16% extruded corn DDGS groups increased the ATTD of ether extract (EE) (P < 0.05). Furthermore, the 8% extruded corn DDGS group increased the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the liver and jejunum, as well as upregulated total antioxidant capacity (T-AOC) activity and the levels of immune factors such as IL-1β, IL-6, IL-10, and TNF-α in the jejunum (P < 0.05). The expression of tight junction-associated proteins, such as claudin-1, occludin, and ZO-1, was also upregulated in this group (P < 0.05). The 16% DDGS supplementation had no significant effect on these indicators, but it reduced the villus-to-crypt ratio in the jejunum (P < 0.05). Additionally, the inclusion of extruded corn DDGS increased the diversity of microorganisms in colonic digesta, significantly reducing the relative abundance of Lactobacillus and Sharpea, while promoting the enrichment of Turicibacter, norank_f_Erysipelotrichae, unclassified_f_Lachnospiraceae, Ruminococcus, and Marvinbryantia (P < 0.05). Taken together, these results indicate that extruded corn DDGS have no adverse effects on growth performance. The addition of 8% extruded corn DDGS can enhance jejunal immunity and barrier function, increase intestinal microbial diversity, and improve EE digestibility by modulating the structure and composition of the gut microbiota. Therefore, extruded corn DDGS could be considered a feasible ingredient to replace corn and soybean meal in piglet diets, thereby reducing feed costs.