This study was conducted to determine the effect weaning has on intestinal alkaline

phosphatase (IAP) activity. IAP is important for enteric health of the growing pig, playing roles

in immune health, intestinal health, digestion, and fat absorption. 12 piglets were weaned at ten

days old and put on standard commercial weaning diet and 12 piglets remained suckling with the

sow as the control treatment. Overall, weaning decreased IAP affinity by 26% and maximal enzyme

activity by 22%.  The main effect was seen in the jejunal region becasue the jejunum expresses 84-86%

of the total gut mucosal IAP activity. Weaning decreased the amount of IAP associated with the

proximal jejunal apical membrane by 64% and proximal jejunal IAP mRNA by 58% which was

associated with a decrease in the abundances of cytoplasmic (27%) and nuclear (29%) IAP caudal-

associated homeobox transcription factor 1. In conclusion, weaning decreased the amount of

IAP available in the pigs gut to facilitate gut and immune health. This may, in part, contribute

to the growth check and increased susceptibility to gastro-intestinal disease in early weaned pigs.