The brown seaweed Laminaria digitata, recognized for its prebiotic properties, combined with alginate lyase supplementation, may support the growth and muscle development of piglets during the sensitive post-weaning stage. This research investigated the impact of including 10% L. digitata and 0.01% alginate lyase on the proteomic and metabolomic profile of the longissimus lumborum in weaned piglets. The results revealed that alginate lyase produced minimal changes in muscle protein composition relative to the effects of seaweed alone compared to the control. Diets containing L. digitata increased the abundance of proteins involved in muscle structure and contraction (ACTBL2) while decreasing glycolytic enzymes such as GPI and ALDOC. Proteins associated with the inhibition of insulin receptor signaling, including RABGAP1 and TSC2, were also elevated. Alginate lyase supplementation, however, increased proteins linked to fatty acid breakdown (ALOXE3) and calcium regulation (WFS1), reflecting dietary n-3 polyunsaturated fatty acids and reduced calcium content. Muscle metabolite profiles remained largely unchanged, except for increases in mannitol and threonine attributed to seaweed inclusion.
