The transition from liquid to solid feed during weaning results in morphological, histological and microbial changes in the young animal’s
intestinal tract and often is associated with diarrhoea. The ban of in-feed antibiotics in pig production in the European Union has led to
increasing interest in alternatives to overcome weaning-associated problems. Among others, nucleotides may have the potential to alleviate
health impairments due to weaning. Nucleotides are natural components of the non-protein fraction of milk and have important effects on
the maintenance of health in young animals. Nucleotides and their related metabolic products play key roles in many biological processes
and become essential dietary components when endogenous supply is insufficient for normal function. The present review summarises
nucleotide composition of milk from different species, the biology of nucleotides and possible effects of dietary nucleotides on intestinal
morphology and function, intestinal microbiota, immune function, nutrient metabolism, hepatic morphology and function as well as
growth performance. Special attention is given to data available for pigs, and suggestions are made for inclusion of nucleotides in the
diet to benefit piglets’ health and reduce the consequences accompanying early weaning