Effect of seaweed-derived laminarin and fucoidan and zinc oxide on gut morphology, nutrient transporters, nutrient digestibility, growth performance and selected microbial populations in weaned pigs.

In the present study, two experiments were conducted to (1) evaluate the effect of laminarin and/or fucoidan on ileal morphology, nutrient transporter gene expression and coefficient of total tract apparent digestibility (CTTAD) of nutrients and (2) determine whether laminarin inclusion could be used as an alternative to ZnO supplementation in weaned pig diets. Expt 1 was designed as a 2x2 factorial arrangement, comprising four dietary treatments (n 7 replicates, weaning age 24d, live weight 6 center dot 9kg). The dietary treatments were as follows: (1) basal diet; (2) basal diet+300ppm laminarin; (3) basal diet+240ppm fucoidan; (4) basal diet+300ppm laminarin and 240ppm fucoidan. There was an interaction between laminarin and fucoidan on the CTTAD of gross energy (GE) (P<0 center dot 05) and the expression of sodium-glucose-linked transporter 1 (SGLT1/SLC5A1) and GLUT1/SLC2A1 and GLUT2/SLC2A2 (P<0 center dot 05) in the ileum. The laminarin diet increased the CTTAD of GE and increased the expression of SGLT1, GLUT1 and GLUT2 compared with the basal diet. However, there was no effect of laminarin supplementation on these variables when combined with fucoidan. Expt 2 was designed as a complete randomised design (n 8 replicates/treatment, weaning age 24d, live weight 7 center dot 0kg), and the treatments were (1) basal diet, (2) basal diet and laminarin (300ppm), and (3) basal diet and ZnO (3100ppm, 0-14d, and 2600ppm, 15-32d post-weaning). The laminarin diet increased average daily gain and gain:feed ratio compared with the basal diet during days 0-32 post-weaning (P<0 center dot 01) and had an effect similar to the ZnO diet. These results demonstrate that laminarin provides a dietary means to improve gut health and growth performance post-weaning.