Traditional Chinese medicine decoction enhances growth performance and intestinal glucose absorption in heat stressed pigs by up-regulating the expressions of SGLT1 and GLUT2 mRNA

This study was conducted to investigate the effects of high temperature stressor on porcine growth performance, small intestinal absorption and SGLT1 and GLUT2 mRNA expressions, and probe the regulation of traditional Chinese medicine decoction (CMD) on them. Forty-eight 2-month-old Chinese experimental pigs were screened according to weight and litter origin, and then allotted to three groups and treated as follows: normal temperature Control group (Control; 23 °C), high temperature stressor group (HS; 26 °C for 19 h, 40 °C for 5 h); Chinese medicine decoction anti-stress group (CMD; 26 °C for 19 h, 40 °C for 5 h) (n = 16 per group). Porcine average dairy feed intake (ADFI), average dairy gain (ADG) and feed:gain ratio (F:G) were examined, and their intestinal disaccharidase activity and xylose absorption were investigated on days 1, 3, 6 and 10 of trial. A method of real-time PCR was applied to determine SGLT1 and GLUT2 mRNA expressions in the small intestine. The results showed that high temperature treatment decreased (p < 0.05) the growth performance and intestinal glucose absorption but there was no change (p > 0.05) in the expressions of SGLT1 and GLUT2 genes in the small intestine compared with the Control. Dietary supplementation with CMD improved porcine growth performance (p < 0.05), as well as increased total disaccharidase activity and xylose absorption in the small intestine of heat stressed pigs on days 3 and 6 (p < 0.05). CMD treatment up-regulated SGLT1 and GLUT2 mRNA expressions of pigs on day 6 compared to the HS and Control groups (p < 0.05). These results indicated that high temperature stressor decreased porcine growth performance and intestinal absorption of pigs, and CMD treatment improved the growth performance and intestinal glucose absorption of heat stressed pigs by up-regulating SGLT1 and GLUT2 mRNA expressions in the small intestine.