Effects of Dietary Marine Sulfated Polysaccharides Derived From Macroalgae on Intestinal Health of Nursery Pigs

Post-weaning stress in pigs leads to intestinal inflammation and oxidative stress. Macroalgae has gained attention with anti-inflammatory and anti-oxidative properties to mitigate these negative impacts. This study aimed to evaluate the efficacy of sulfated polysaccharides extracted from marine macroalgae (Ulva spp. and Solieria chordalis) promoting intestinal health and growth performance in nursery pigs. Twenty-four nursery pigs at 21 days of age, with initial body weight (BW) of 6.5 ± 0.2 kg, were allotted to dietary treatments in a randomized complete block design, with sex and BW as blocks. Pigs were assigned to either a control diet or a diet supplemented with 0.2% mixed macroalgae. Growth performance was recorded by phase. At 56 days of age (day 35 of the study), pigs were euthanized to collect jejunal tissues and mucosa to evaluate intestinal health. Supplementation with 0.2% mixed macroalgae decreased (p < 0.05) TNF-α, tended to decrease (p = 0.064) IL-8, and decreased (p < 0.05) protein carbonyl in jejunal mucosa, indicating reduced intestinal inflammation and oxidative stress, suggesting a potential protective effect of macroalgae in jejunum. In conclusion, dietary inclusion of 0.2% mixed macroalgae may serve as a functional strategy to support intestinal health in nursery pigs under inflammatory stress.