Effects of supplementing dietary laminarin and fucoidan on intestinal morphology and the immune gene expression in the weaned pig.

Previous studies have shown the benefit of combining seaweed extracts laminarin (LAM) and fucoidan (FUC) on improving growth in piglets' performance after weaning. A 2 × 2 factorial experiment was conducted to investigate the interaction between FUC (0 and 240 mg/kg) and LAM (0 and 300 mg/kg) levels on gut morphology and colonic cytokine gene expression in the weaned pig. Twenty-eight piglets (6.9 kg BW) were assigned to 1 of 4 dietary treatments for 8 d after weaning and then sacrificed. The dietary treatments were as follows: (i) basal diet, (ii) basal diet + 240 mg/kg FUC, (iii) basal diet + 300 mg/kg LAM, and (iv) basal diet + 300 mg/kg LAM and 240 mg/kg FUC. There was an interaction (P < 0.01) between LAM and FUC supplementation on duodenal villous height and the villus height to crypt depth ratio. Pigs offered the LAM or FUC diet singularly had an increased villus height and villus height to crypt depth ratio compared with pigs offered the basal diet. However, there was no effect of the LAM and FUC combination diet on morphology. Pigs offered the LAM-supplemented diets had a lower IL-6 (P < 0.05), IL-17 (P < 0.001), and IL-1β (P < 0.001) mRNA expression in the colon compared with pigs offered diets without LAM supplementation. In conclusion, the enhancement in intestinal structure and downregulation of inflammatory cytokine gene expression obtained suggest that LAM may provide a dietary means to improve gut health in weaned pigs.