Developmental changes of jejunal brush-border enzyme activity in growing Jinhua gilts

The present study was aimed to investigate the developmental changes of small intestinal morphometry and jejunal brush-border enzyme activity in growing Jinhua gilts. The weight, length, and mucosa weight of the small intestine were measured at 35, 80 and 125 days of age, respectively. Sucrase, maltase, lactase and alkaline phosphatase (ALP) activities of the jejunal brush-border membrane were determined at the respective stages. Body weights and body weight gains significantly increased with age (P<0.05). Weights of the small intestine and of the intestinal mucosa increased faster from 35 to 80 d than from 80 to 125 d (P<0.05). Weights of the duodenum, jejunum, and ileum, and mucosa from the respective sections increased with age (P<0.05). Mucosa weight relative to the weight of the section was greater (P<0.05) for the duodenum, jejunum than for the ileum. Jejunal maltase and sucrase activity increased with age (P<0.05), whereas, lactose and ALP activity decreased with age (P<0.05) during growth. There was a 15-fold increase in both total jejunal maltase and sucrase activity from 35 to 125 days of age, and a 5-fold increase in both total jejunal lactase and ALP activity; the greatest rate of increase occurred between 35 and 80 days of age. The results suggest increases in body weight of growing Jinhua gilts are accompanied by significant developmental changes in intestinal weight, length and mucosal weights as well as jejunal brush border maltase, sucrase, lactase and ALP activities.