Remodeling of Hepatic Glucose Metabolism in Response to Early Weaning in Piglets.

This study aimed to investigate the dynamic changes in hepatic glucose metabolism in response to early weaning. A total of 60 piglets were randomly selected and weaned at 21 days old. Six piglets were slaughtered on the weaning day (d0) and at 1 (d1), 4 (d4), 7 (d7), and 14 (d14) days postweaning. The results illustrated that body weight significantly increased from d4 to d14 ( p < 0.001). Serum glucose fell sharply after weaning and then remained at a low level from d1 to d14 ( p < 0.001). Serum insulin decreased from d4 ( p < 0.001), which caused hepatic glycogen to be broken down ( p = 0.007). The glucose-6-phosphatase activity increased from d0 to d4 and then decreased from d4 to d14 ( p = 0.039). The pyruvate carboxylase activity presented a significant sustained increase from d0 to d14 ( p < 0.001). The succinate ( p = 0.006) and oxaloacetate ( p = 0.003) content on d4 was lower than that on d0. The succinate dehydrogenase activity ( p = 0.008) and ATP ( p = 0.016) production decreased significantly on d4 compared to that on d0. Taken together, these findings reveal the dynamic changes of metabolites and enzymes related to hepatic glycometabolism and the TCA (tricarboxylic acid) cycle in piglets after weaning. Our findings enrich weaning stress theory and might provide a reference for dietary intervention.